source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-1701 | ecology, population-dynamics, ecosystem, antipredator-adaptation, predation
I would also like to talk about other things that might be of interest in your model (two of them need you to allow evolutionary processes in your model):
1) lineage selection: predators that eat too much end up disappearing because they caused their preys to get extinct. This hypothesis has nothing to do with some kind of auto-regulation for the good of species. Of course you'd need several species of predators and preys in your model. This kind of hypothesis are usually considered as very unlikely to have any explanatory power.
2) Life-dinner principle. While the wolf runs for its dinner, the rabbit runs for its life. Therefore, there is higher selection pressure on the rabbits which yield the rabbits to run in average slightly faster than wolves. This evolutionary process protects the rabbits from extinction.
3) You may consider..
more than one species of preys or predators
environmental heterogeneity
partial overlapping of distribution ranges between predators and preys
When one species is absent, the model behave just like an exponential model. You might want to make a model of logistic growth for each species by including $K_x$ and $K_y$ the carrying capacity for each species.
Adding a predator (or parasite) to the predator species of interest
... and you might get very different results.
The following is multiple choice question (with options) to answer.
An animal species' population may decrease because of | [
"construction activity",
"mating",
"more food",
"growth"
] | A | harming an animal species causes that animal 's population to decrease |
OpenBookQA | OpenBookQA-1702 | measurements, home-experiment
Title: How to measure speed of a ceiling fan? I thought for fun I might measure how my ceiling fan slows down when turned off, and maybe find out what forces act on it when it slows down. My problem is that for that I need to measure its rotational speed when it's turned on. When it's in the lowest speeds it's easy because you can see it rotate, but for higher speeds that's not an option.
I thought one way would be to use a strobe light and try to match up the frequency, but I don't have one of those. Can you think of any DIY way to measure the speed of a very fast ceiling fan? If you have a smart phone with a flash, you probably have a strobe feature at your disposal.
You can put a drinking straw into it and record the sound it makes, and measure the frequency in sound-editing software. Imagine the fun explaining this to paramedics.
Similarly, a laser-pointer, a mirror, and a photo-diode cleverly hooked up to your computer's sound card can be coaxed into doing science.
Finally, a laser pointer, two mirrors and knowledge of the speed of light in your room can be used to to determine the rotational speed of the fan, provided your room is big enough, and the fan is moving fast enough. If this is going to work, it will probably be the least accurate but most fun.
The following is multiple choice question (with options) to answer.
Speed is measuring how fast an object is doing what? | [
"melting",
"evaporating",
"rotating",
"changing location"
] | D | speed is a measure of how fast an object is moving |
OpenBookQA | OpenBookQA-1703 | reproduction, human-genetics, human-genome
I missed the "as a species" part of your question. Inbreeding will only likely have an effect within small, closed populations, though it will continue to have a lasting effect even as those populations grow and open up. Two textbook examples are French Canadians and Ashkenazi Jews. Even now, there is continued elevated risk of certain rare genetic diseases in these populations. As for the species as a whole, it is likely to be really detrimental only if the effective population size of the species becomes really low: a general rule of thumb used by conservation biologists is that the effective population size should be at least 50 to avoid the effects of inbreeding (and 500 to avoid the effects of genetic drift) (50/500 rule).
Sorry about the confusion.
The following is multiple choice question (with options) to answer.
As the population of zebra decreases | [
"competition among African wild dogs increases",
"predators learn to swim",
"prey communities get larger",
"prey will be more visible"
] | A | as the population of prey decreases , competition between predators will increase |
OpenBookQA | OpenBookQA-1704 | species-identification, zoology, marine-biology, arthropod
Title: What is this large, lively barnacle? Yesterday I found this creature in a rocky cove in central California, around mid tide (+ 3 feet). It's about 3-4 inches long. At first I thought it was dead, but it closed its mouth when I removed the tiny white pebble, and rotated the operculum rapidly when I poked the bit of exposed yellowish flesh underneath. I think it's some sort of acorn barnacle, but haven't been able to identify a species with the white shell and distinctive red-and-white color and texture differences on the opercular plates. What could it be? Update: this is a giant acorn barnacle, Balanus nubilis. Between Pacific Tides mentions that they can vary widely in coloration, and there's a picture of a similarly colored one here.
We had our ID confirmed by email by a representative of the Monterey Bay Aquarium, who added this info:
You beat me to it. That is indeed a giant acorn barnacle (Balanus
nubilus). Unfortunately, barnacles can’t survive long after being
detached from their rocks and they’re unable to reattach on their own.
Rocky intertidal zones are harsh environments and animals living in
these areas must deal with both water and air, rapidly changing
temperatures, exposure to sunlight, desiccation, high wave energy, and
predators from both land and sea.
The stringy threads attached to the barnacle in your photo are the
byssal threads of California mussels. Mussels secrete these threads
to anchor themselves to rocks, each other, barnacles, etc. It’s very
common to see mussels and barnacles clumped together in high surf
zones.
The following is multiple choice question (with options) to answer.
Squirrels can often be seen storing acorns during the | [
"summer",
"spring",
"fall",
"winter"
] | C | squirrels gather nuts in the autumn to eat during the winter |
OpenBookQA | OpenBookQA-1705 | human-biology, biochemistry, metabolism, food
Which seem to go in different, rather contradictory directions.
Also, Studies partially supporting either viewpoint can be found:
Study considering hemoglobin A1c levels
Study considering peak glucose levels
Study considering snacking
Which leaves the non-biologist asking themselves which is the "major effect" (certainly, there will be some truth to each position, but the question is which one(s) got the "main point"), and if there are any other important effects to be considered, hence this broad question here, so I understand, from a biological standpoint, what happens to the carbohydrates when I eat them, so I can conclude for myself how to adapt my diet for "optimal" health. Scope of Answer
The original poster provided ample context for his question, which related to health considerations. It was perhaps for this reason, among others, that the question had not received an answer at the time of writing: questions relating to medical or health advice are off-topic here. However, his actual question is primarily biochemical:
What are the biological differences between the digestion of sugar and
different types of carbs as constituents of different types of food in
humans?
Although this might be answered with a little internet search, I felt it would be hospitable if someone offered him an answer to this — and this only.
Definitions
The basic sugar unit is a mono-saccharide, those of relevance to this question being hexoses or pentoses, having six or five carbon atoms, respectively.
What in non-technical language is called sugar, refers to a specific molecule, sucrose, which is a disaccharide of covalently-bonded glucose and fructose.
What in non-technical language are referred to as dietary carbohydrates generally refers to the storage polysaccharide of plants such as potato and other root vegetables, rice, and other cereal crops used to make bread. This is a homo-polymer composed solely of glucose units.
Summary of the differences in metabolism
Arising from these definitions, the following differences in metabolism emerge:
Different enzymes (amylase for these polysaccharides, sucrase for saccharose) are used to catalyse the hydrolysis of the linkages between the monomeric units.
Absorption in the gut is different for glucose and fructose, as is transport into cells.
The following is multiple choice question (with options) to answer.
An example of something that contains sugar is | [
"air",
"cats",
"wind",
"Peppers"
] | D | carbohydrates are made of sugars |
OpenBookQA | OpenBookQA-1706 | zoology, ecology, species-distribution, migration
Title: How do animals end up in remote areas? I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough.
They usually don't seem to be connected to each other. If it were any other land animal I would figure they walk from one spot to another, but in the case of frogs, I don't imagine their range is very vast. But often these marshy spots can be separated by fairly large distances to a frog.
So this brings me to my question: how do each of these spots end up with frogs in them? I don't imagine a frog is going to go hopping over a hill to get to a marsh on the other side, is it? This question pertains to organism dispersal, which is a very active field of study with relation to it's impact on conservation efforts. Much of what I will say below has been covered in this wiki.
Definition: From the Wiki
Technically, dispersal is defined as any movement that has the
potential to lead to gene flow.
It can be broadly classified into two categories:
Density dependent dispersal
Density independent dispersal
The question of frogs and fishes both refer to Density independent dispersal, while an example of density independent dispersal can be the competition for habitat space between big cats and humans (this is a WWF pdf)
From the wiki:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage
of various forms of kinetic energy occurring naturally in the
environment. This is referred to as density independent or passive
dispersal and operates on many groups of organisms (some
invertebrates, fish, insects and sessile organisms such as plants)
that depend on animal vectors, wind, gravity or current for dispersal.
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends
on factors such as local population size, resource competition,
habitat quality, and habitat size.
Currently, some studies suggest the same.
This study in particular studied the movement and habitat occupancy patterns within ephemeral and permanent water bodies in response to flooding. They found that during flooding these frogs moved out to flooded ephemeral water bodies and later on moved back again to the permanent ones.
Other suggested readings for those highly interested in the subject may include this (a phd thesis) and this (a project report)
The following is multiple choice question (with options) to answer.
What can cause animals to leave an environment? | [
"grass",
"abundant food",
"earth tremors",
"natural winds"
] | C | natural disasters can cause animals to leave an environment |
OpenBookQA | OpenBookQA-1707 | asteroids, comets
Title: How significant are the recent results that Scholz’s Star has perturbed several observed hyperbolic objects? The Gizmodo article A Visiting Star Jostled Our Solar System 70,000 Years Ago refers to the the three year old ApJ. paper The Closest Known Flyby of a Star to the Solar System (also arXiv) which describes Scholz’s Star and it's pass close to our solar system about 70,000 years ago.
The Gizmodo article then discusses the newly published paper in MNRAS Where the Solar system meets the solar neighbourhood: patterns in the distribution of radiants of observed hyperbolic minor bodies. However, while I can access the earlier paper, the new result is paywalled and I'm not able to access it (at least not soon).
The second half of the abstract in particular is confusing me.
Here, we perform a systematic numerical exploration of the past orbital evolution of known hyperbolic minor bodies using a full N-body approach and statistical analyses to study their radiants. Our results confirm the theoretical expectations that strong anisotropies are present in the data. We also identify a statistically significant overdensity of high-speed radiants towards the constellation of Gemini that could be due to the closest and most recent known fly-by of a star to the Solar system, that of the so-called Scholz's star. In addition to and besides 1I/2017 U1 (‘Oumuamua), we single out eight candidate interstellar comets based on their radiants’ velocities.
The following is multiple choice question (with options) to answer.
what celestial body is after the 8th one in this solar system? | [
"earth",
"venus",
"pluto",
"jupiter"
] | C | Pluto is the planet that is ninth closest to the Sun |
OpenBookQA | OpenBookQA-1708 | mountains, rainfall
Title: Could a waterfall lashing onto a road lead to a landslide? Here is a video of a waterfall lashing on to a mountain road, with vehicles driving under it.
https://youtu.be/cHaguj--YBc
There appears to be a big hole carved out right next to the road, possibly by the force of the waterfall.
Is this a ticking time bomb for a landslide? Potentially, a landslide could occur. Whether it would be a minor slip or a major fall depends on the geological conditions at the site, the force of the water and the duration that the site is impacted by the water.
In the video in question, the rock face above the road appears competent, but there are not guarantees. The main issue would be is the water undermining the road which could cause a slip and the road to slide.
The more loose the geological material is, the easier it is to dislodge it. Once one item moves a chain of events can occur where additional items are dislodged and a slide occurs.
In addition to high pressure water dislodging material, water acts as a lubricant, making it easier for rocks and regolith to be dislodged.
To minimise the potential for a slide to occur in such a situation, the surface of the road would need to be sealed very well and a very good drainage system installed that would move the water away from the road and the slope below the road
The following is multiple choice question (with options) to answer.
A landslide is likely to occur on a slope as | [
"there is less vegetation",
"downward movement is facilitated",
"there is more debris",
"it means more shifting occurs there."
] | B | landslides often occur on mountains |
OpenBookQA | OpenBookQA-1709 | geology, rocks, mineralogy
Title: What is this Lake Michigan rock? Rock found along northern Lake Michigan, (Charlevoix, MI). Made up of very thin crystalline layers. There are small, round bubble like bumps that protrude from the surface. Doesn't show well in the picture, but the rock has a sugary appearance. I can't be definite but my three best guesses are Travertine, Agate and maybe Halite, if it fizzes in mild acid it's Travertine, a form of Limestone, if it dissolves in hot water it's Halite, or Rocksalt, otherwise if it's more or less inert it's probably Agate, an amorphous silicate. I find Halite unlikely, the other two are probably pretty equally likely in that location.
The following is multiple choice question (with options) to answer.
Lake Ontario formed from | [
"construction workers",
"mechanical weathering",
"tectonic shifts",
"asteroids"
] | B | a glacier causes mechanical weathering |
OpenBookQA | OpenBookQA-1710 | hydrology, rivers, dams
Title: Do dams reduce the flow of river downstream? There is a conflict between Egypt and Ethiopia, because the latter wants to build a dam on the Nile river. Citing this article:
[Egypt] fears the Nile dam will reduce its share of the river and leave the
country with dwindling options as it seeks to protect its main source
of fresh water.
What do they mean by "reduce its share of the river"? As far as I understand, the dam will create a reservoir, which will initially divert some water to be filled, but once that is done, the flow of the river should be the same. Is Egypt worried about this initial reduction, or do dams somehow reduce the flow of a river?
If so, what is the mechanism? I would guess that this is due to increased evaporation from the river, since the reservoir has a bigger surface than the usual river, but then again, it also collects more rain. Once a dam has been constructed in a river, the natural flow of water will be disrupted.
You correctly state that initially there will be a period required for the dam to fill. Until then, little of no water will flow beyond the dam.
Dams are created for one or more of three reasons:
To supply potable water to a population of humans for domestic or
industrial purposes.
For agricultural purposes.
To generate hydro-electricity.
The following is multiple choice question (with options) to answer.
If a river dries, deer may | [
"detect more water",
"carry on without",
"restore it",
"quest for sources"
] | D | if the amount of available food and water decreases in an environment then animals may leave that environment to find food and water |
OpenBookQA | OpenBookQA-1711 | terminology, meteorology
I've tried to illustrate the relationships with insolation and temperature here:
There are some other ways too:
Ecological. Scientists who study the behaviour of organisms (hibernation, blooming, etc.) adapt to the local climate, sometimes using 6 seasons in temperature zones, or only 2 in polar and tropical ones.
Agricultural. This would centre around the growing season and therefore, in North America and Europe at least, around frost.
Cultural. What people think of as 'summer', and what they do outdoors (say), generally seems to line up with local weather patterns. In my own experience, there's no need for these seasons to even be 3 month long; When I lived in Calgary, summer was July and August (hiking), and winter was December to March (skiing). Here's another example of a 6-season system, and a 3-season system, from the Aboriginal people of Australia, all based on weather.
Why do systems with later season starting dates prevail today? Perhaps because at mid-latitudes, the seasonal lag means that the start of seasonal weather is weeks later than the start of the 'insolation' period. In a system with no heat capacity, there would be no lag. In systems with high heat capacity, like the marine environment, the lag may be several months (Ibid.). Here's what the lag looks like in three mid-latitude cities:
The exact same effect happens on a diurnal (daily) basis too — the warmest part of the day is often not midday (or 1 pm in summer). As with the seasons, there are lots of other factors too, but the principle is the same.
These aren't mutually exclusive ways of looking at it — there's clearly lots of overlap here. Cultural notions of season are surely rooted in astronomy, weather, and agriculture.
The following is multiple choice question (with options) to answer.
Spring for north of the equator and Autumn for below the equator are attributed to | [
"earth's rotors",
"earth's slant",
"earth's games",
"earth's tone"
] | B | the Earth being tilted on its axis causes seasons |
OpenBookQA | OpenBookQA-1712 | radiation
You see similar things happening here. The metal rod at the top of the lamp acts as a capacitive ground - given the very high voltage, a tiny charge will flow from the tip of the filament to the rod. There is a small amount of gas in the tube which is ionized and gives rise to the light you see. The electrons eventually bombard the metal "anode" and produce Bremsstrahlung - note that without the metal, you were getting a glow and no reading on the Geiger counter. There is a similar demonstration online which is more convincing in its use of conventional materials, but which otherwise shows many of the same phenomena.
It is almost certainly very inefficient. Most of the energy in an X-ray tube is converted to heat as the electrons burrow too deeply into the tungsten target for their radiation to escape- apart from the fact that only the most violent deceleration produces X-rays with high enough energy to penetrate the bulb and be detected.
I noticed that when the "alpha window" was removed, the reading in your video went up. Since there was also a biscuit tin and glass bulb in the way I suspect there was a lot more low energy radiation generated than was detected. Good stuff for skin cancer.
The experiment as shown should not be repeated. Not only were the HV precautions extremely poor, but so were the radiation safety precautions. Please don't try this at home...
The following is multiple choice question (with options) to answer.
An unusual use for a flashlight may be | [
"a fridge",
"hand warmer",
"a plate",
"the new sun"
] | B | a flashlight emits light |
OpenBookQA | OpenBookQA-1713 | mechanical-engineering, gears
Hopefully this all makes sense so far.
A lever doesn't actually move strictly up-and-down, though. It rotates about the fulcrum. The actual distance the input traverses is $L_1\theta$, and the output moves $L_2\theta$, where $L_1$ is the length of the lever from the input side to the fulcrum, $L_2$ is the length of the lever from the output side to the fulcrum, and $\theta$ is the angle of how much the lever rotated.
Define the arc length, or distance actually traveled by the input or output end of the lever to be $s$. The input moves:
$$
s_1 = L_1\theta \\
$$
The output moves:
$$
s_2 = L_2\theta \\
$$
If you divide the output by the input, you can see that:
$$
\frac{s_2}{s_1} = \frac{L_2\theta}{L_1\theta} \\
$$
The thetas cancel, and you're left with:
$$
\frac{s_2}{s_1} = \frac{L_2}{L_1} \\
$$
which can be restated as:
$$
\boxed{s_2 = \left(\frac{L_2}{L_1}\right)s_1} \\
$$
The output distance traveled is equal to the input distance times the ratio of lever arm lengths. You can plug this back into the work equation:
$$
F_1 s_1 = F_2 s_2 \\
F_1 s_1 = F_2 \left(\frac{L_2}{L_1}\right)s_1 \\
$$
Cancel the $s_1$:
$$
F_1 = \left(\frac{L_2}{L_1}\right)F_2 \\
\boxed{F_2 = \left(\frac{L_1}{L_2}\right)F_1} \\
$$
The following is multiple choice question (with options) to answer.
What is a lever used to move? | [
"planets",
"small objects",
"liquids",
"substantial objects"
] | D | a lever is used for moving heavy objects |
OpenBookQA | OpenBookQA-1714 | virus
Assuming that you're not going splunking in bat inhabited caves in West Africa, it's safe to assume that what we are worried about is human to human transmission through infectious fluids. Ebola actual isn't that stable in water, so just soaking a surface in water and a little oil might help you out (if you don't have bleach handy). I want to be clear that I'm not recommending this, in reality you should just avoid contaminated objects. I think that we have clearly established that what we're really concerned about is infectious bodily fluid.
This leads me to the wonderful note by Jose Martin-Moreno titled "Is respiratory protection appropriate in the Ebola response?" I don't think I can express the problem better than he can, so hopefully I will be allowed a substantial quote:
This transmission [of ebola] occurs via close family contact or in
health-care settings, particularly when placing orotracheal intubation
or when caring for a patient who is vomiting or bleeding. Ebola is
rarely transmitted via an airborne route. Although these routes of
transmission are well known, most agencies, including governmental
agencies responsible for repatriating western patients, apply
infection-control measures appropriate for airborne diseases.
Excessive precautions could offer reassurance to those responding to
Ebola, yet complete respiratory protection is expensive,
uncomfortable, and unaffordable for countries that are the most
affected. Worse, such an approach suggests that the only defence is
individual protective equipment, which is inaccessible to the general
population. Moreover, the image of workers with spectacular protective
clothing might contribute to the panic in some communities. If this
leads people to flee affected areas it could increase the spread of
infection.
The following is multiple choice question (with options) to answer.
Weakened agents are introduced to kids to prevent | [
"strep",
"common cold",
"measles",
"diarrhea"
] | C | vaccines can help prevent illness |
OpenBookQA | OpenBookQA-1715 | geology, geomorphology, coastal
Title: What causes such a narrow slit in a cliff? (see photo)
I have this photo as a background image and I often wonder how such a narrow, well-defined slit could be formed. Is it natural or man-made? If natural, what processes could have formed it? The rest of the coastline is rugged but this appears very uniform. It is on the north-west coast of Jersey (UK). If you see the other user (Jan Doggen's) google maps link, you can see apparently similar features in different states - this is a particularly neat example of a general phenomenon.
These notches form when headlands are undercut by caves carved out by the sea. They may be initiated where there is a fault or jointing in the rock (northwest Jersey is granite, according to google).
In this particular case, the notch seems to have a rounded termination. Blowholes also form from undercutting of headlands producing caves whose roofs then collapse. It's possible this cave may have collapsed after a blowhole formed, so you get a notch where the inland end of the feature appears rounded. That bit is just speculation though.
I found this Jersey geology trail guide that might have more detail: http://jerseygeologytrail.net/Geomorph.shtml
The following is multiple choice question (with options) to answer.
Slate probably formed | [
"on top of a glacier",
"somewhere in the Internet",
"on a mountain top",
"deep within the earth"
] | D | shale can be metamorphosed into slate by increased pressure |
OpenBookQA | OpenBookQA-1716 | star, night-sky
Title: What is this rapidly twinkling red, blue, and white star I saw? Last night, I was on my balcony at 1AM (PST) and I looked up and saw two stars near the horizon (I'd guess ~30 degrees above the horizon), and they were "twinkling" about twice as fast as other stars higher in the sky, and I could clearly see them changing from red to white to blue repeatedly. Other stars in the sky only appeared white to me, and didn't seem to "twinkle" as rapidly as these two stars did. The red and blue make me think of red-shift and blue-shift, but I don't know how I would see both from the same object.
What was I seeing?
I don't know if it helps, but I am in the Los Angeles area, and I was looking in a roughly north direction. almost exactly to the east, according to google maps.
Edit: I tried taking a picture, but light pollution from the nearby street lights wouldn't permit me taking a decent picture. However, I noticed a group of three stars close together in nearly a perfect almost vertical line, and managed to find that in Stellarium. I think I found the two stars I am seeing: Procyon and Sirius
Is there anything about either of these stars that would make them show as red/blue? It's most probably Sirius. At this time of year (at 1 am local time) it's low in the sky in the East, so there is a lot of atmosphere in the way, and as Sirius is a bright bluish star, it will show all the colours described as it twinkles.
The following is multiple choice question (with options) to answer.
At night stars appear to move relative to the | [
"moon",
"skyline",
"treetops",
"ocean"
] | B | stars appear to move relative to the horizon during the night |
OpenBookQA | OpenBookQA-1717 | ecology, behaviour, sociality, predation, community-ecology
Title: How selective are wolves about the size of their prey? For an animal that lives and hunts socially like a wolf, is there a lower threshold to the size of prey items they will hunt? A pack wouldn't have much trouble with catching say a rabbit, but would the food provided be enough to actually make the hunt worthwhile? What is the limit in which a prey item becomes too small to be worth catching? You should not post here until you've demonstrated your own research effort. Given this stipulation -- and the rich literature about this very topic -- I will keep my answer cursory so as to act as starting points for your search. A simple Google or google Scholar search on your part will reveal many more details/studies.
You should review the following ecological concepts: prey switching, optimal foraging theory, principle of allocation, and others.
Some accessible articles on Prey-to-predator-size ratio include: Henriques et al. 2021, Tsai et al 2016, Cohen et al 1993, and Vézina 1985
Regarding wolves:
According to Becker et al 2018:
[Wolf] Prey selection is influenced by the absolute and relative abundances of prey types, the life history characteristics of predators and prey, and the attributes of the environment in which these interactions occur.
Smith et al. 2010 demonstrate that diets vary with season -- their focus being on winter diets.
Huggard 1993 shows the impact of environmental variables such as snow.
Herd density plays a significant role:
Sand et al. 2016
Davis et al 2012 showed that lower density of secondary prey mattered more than heightened density of primary prey.
Huggard 1993 (Canadian Journal of Zoology) showed that density of herds (vs herd density) mattered more in Banff National Park in Canada. Herd size and habitat also mattered -- with wolves avoiding some habitats and seemingly choosing places that optimized preferred habitats and large herd size.
Wolf scat/diet studies showing smallest species in their diet:
Sin et al 2019: smallest for Sandanavian wolves = domestic dogs
Nowak et al 2011 showed the following small prey made up the stated percentages of wolve's diets in Poland:
brown hare Lepus europeus (2.5%) and Eurasian beaver Castor fiber (1.4%). Domestic animals, exclusively dogs and cats, made up 1.0% of food biomass.
Works cited:
The following is multiple choice question (with options) to answer.
Some prey animals may elude predators by | [
"being stinky",
"being friendly",
"being slow",
"being loving"
] | A | most animals avoid bad odors |
OpenBookQA | OpenBookQA-1718 | species-identification, marine-biology
Title: help identify this fish
I came across this washed up fish in Panama City, Florida in November 2015. I'm guessing it's a puffer fish but I can't find anything like it online.
Thanks. This is a kind of trunkfish. (They have different names, this could be a smooth or spotted trunkfish.). It's really a lovely and comical little fish when observed alive in coral reefs. It has the ability to change its coloration depending on whether it's excited or calm, or to minimize its contrast to the background. It is related to puffer fish.
It has a boxy, triangular body shape, and propels itself with relatively tiny, delicate fins. Like pufferfish, they are toxin producers.
In death, the body shape and coloration are different, of course. Never saw a dead one before; sad. The juveniles are adorable:
Members of this family occur in a variety of different colors, and are notable for the hexagonal or "honeycomb" patterns on their skin. - Wikipedia
The following is multiple choice question (with options) to answer.
A fish lives in | [
"dihydrogen monoxide",
"carbon monoxide",
"dihydrotestosterone",
"iron sulfate"
] | A | a fish lives in water |
OpenBookQA | OpenBookQA-1719 | evolution, speculative
Title: Why Didn't Evolution Cause the Human Body to become Streamlined? If streamlining makes movement/locomotion quicker and easier, why didn't the apes evolve into life-forms that had streamlined bodies (much like fish)?
If streamlining makes movement/locomotion quicker and easier, why didn't the apes evolve into life-forms that had streamlined bodies (much like fish)?
As with everything in Evolutionary Biology, you must ask yourself: Gain vs. Cost?
In your specific case, the Gain is very little. Air isn't nearly as dense as water, so a streamlined form won't show a major benefit unless the organism is traveling very, very quickly. This is why you see it in birds; raptors can travel over 100mph while diving, and at those speeds small changes in drag can mean the difference between dinner and starving. Smaller birds often make very quick turnabouts and changes in direction mid-flight where, again, small changes in efficiency can mean the difference between life and death. The cost was is worth it.
For apes and monkeys, moving very quickly isn't a case of living or dying. That's what we evolved opposable thumbs and prehensile feet(/tails) for. You don't need to run fast when you can climb a tree and simply get away from any predators on the ground. After we came down from the trees permanently, our larger brains allowed us to use tools to fend off predators - which, again, is much simpler than evolving an aerodynamic form that won't make a difference until you're running at the speed of a car.
So, in lieu of becoming a land-shark, we have hands that can use keyboards and minds that can invent the keyboard. Unfortunately, while the gains are many, the costs do include both a very long period of time where humans are helpless without parents, and an absolutely terrible form of locomotion with our upright stance on forward-pointing knees. Though you won't catch Cheetahs digging sewers anytime soon.
The following is multiple choice question (with options) to answer.
A flamingo may be able to run across a pond easier than a human, sparrow or a cat because it has | [
"webbed feet",
"a tail",
"wings",
"a beak"
] | A | webbed feet are used for moving faster through water by aquatic animals |
OpenBookQA | OpenBookQA-1720 | biochemistry
Title: Is hydrolysis of polypeptides and polysaccharides "anabolic" or "catabolic" When a polysaccharide or polypeptide is hydrolyzed into mono-saccharides or amino acids, the building blocks can be oxidized to release energy. The oxidation is considered to be catabolic since it reduces the building blocks to simple compounds: carbon dioxide, water, ammonia, and releases energy.
Is the process of hydrolysis that breaks up polypeptides and polysaccharides a net endothermic or exothermic process?
Do the free amino acids and monosaccharides have more or less stored energy than the polypeptide or polysaccharide that they were broken down from?
Is it proper to call the isolated process of "hydrolysis" of proteins and polysaccharides "catabolic"?
Are protein synthesis, glycogen synthesis, (and triglyceride formation), by dehydration synthesis processes that require energy or release energy. I think that they release energy which is semantically interesting since protein and glycogen synthesis are the main examples of anabolism in the body but may actually release energy which is a key component of the definition of catabolism. Even if the energy released from protein synthesis is not generating ATP directly, wouldn't the heat produced conserve ATP in the long run.
1) Is the process of hydrolysis that breaks up polypeptides and polysaccharides a net endothermic or exothermic process?
Under physiological conditions, it is a process that goes forward, i.e. the Gibbs energy is negative. As a consequence, it can happen outside of cells in the absence of ATP. When we eat, the hydrolysis of polysaccharides starts in our mouths, while the hydrolysis of proteins occurs under harsher (acidic) conditions in the stomach and continues in the intestine (slightly basic conditions).
For warmblooded animals like us, exothermic or endothermic is less important, but you could look it up.
2) Do the free amino acids and monosaccharides have more or less stored energy than the polypeptide or polysaccharide that they were broken down from?
The following is multiple choice question (with options) to answer.
What breaks down food to produce energy? | [
"life forms",
"food packaging",
"refrigerators",
"the sun"
] | A | cellular respiration is when cells break down food to produce energy |
OpenBookQA | OpenBookQA-1721 | evolution, botany, development, fruit, seeds
What is the point of fruit if not to be eaten? It’s my understanding that organisms will adapt to survive and thrive. I understand that being eaten can spread seeds, but this just seems like too much of a risky tactic to rely on.
Following on from part one: If being eaten is the best way to spread seed, why do some plants avoid this (such as by being poisonous or thorny)? Seeds are spread by many mechanisms
Wind dispersal: When air currents used to spread seeds. Often these plants have evolved features to facilitate wind catching, for example dandelions. Aka, anemochory.
Propulsion & bursting: When seeds are propelled from the plant in an such as in these videos. This is called Ballochory.
Water: Similarly to wind dispersal plants can spread seeds by water movement/currents, aka Hydrochory. This is used by many algae and water living plants.
Sticky Seeds: There are many ways a seed can attach to the outside of an animal - by using hooks, barbs, sticky excretions, hairs. Seeds then get carried by an animal and fall off later. This is epizoochory.
Fruiting: Plants can use seed-bearing fruit to encourage animals to eat the seeds. They will then be spread when the waste is excreted after digestion. This is a process of endozoochory.
More than one way to spread a seed
The following is multiple choice question (with options) to answer.
Birds are a vehicle for spreading the seeds of what? | [
"winds",
"dissent",
"flame",
"oaks"
] | D | birds are a vehicle for spreading the seeds of a plant |
OpenBookQA | OpenBookQA-1722 | atmosphere, temperature, humidity, atmospheric-optics
Source As described here, condensation of cloud particles (i.e., contrail formation) will occur if the mixing between hot and moist exhaust from an aircraft engine and ambient environmental air results in the mixed air exceeding the ice saturation vapor pressure as its temperature changes. A conceptual diagram of this mixing process is shown here, for exhaust (parcel A) and environmental air (parcel B) with generic temperatures and saturation vapor pressures is shown here:
However, this would require knowledge of these specific temperatures and corresponding saturation vapor pressures. More practically, contrail prediction often just assumes that the air at altitudes where jets typically cruise (commonly, though not always, above 8 km/26,000 ft and at air temperatures below -40°C) is near or above supersaturation with respect to ice. This assumption is used operationally, for example, in NASA's publicly-available persistent contrail forecast. Note that the first source indicates that low wind speeds are also useful in identifying likely regions of persistent contrails.
Several sources of data may be useful in constructing similar analyses or forecasts and comparing to what might be expected on an average day, based on the local climatology. Observational data from radiosondes (i.e., weather balloons with instruments measuring temperature, moisture, and winds) is available globally in near-real time. This provides actual measurements of weather conditions through the relevant altitudes for contrail formation, and is particularly useful if measurements are needed relatively close to a radiosonde launch site.
For broader coverage in both space and time, the US National Oceanic and Atmospheric Administration provides archives of past weather analyses and operational forecast model output that can be requested by the general public. These datasets contain gridded model output with common parameters at various levels through the atmosphere on a national to global scale. While these datasets do not strictly consist of observed measurements, they are useful for analyses extending beyond the relatively limited set of observations available in most circumstances. Output from various operational forecast models is available for near-current or future conditions, whereas the reanalysis datasets provide similar information obtained from model analyses of past weather.
The following is multiple choice question (with options) to answer.
Extreme negative temperatures can cause a gaseous cloud to | [
"condense to solid",
"expand outwardly",
"disappear all together",
"become a liquid"
] | A | freezing causes a solid to form |
OpenBookQA | OpenBookQA-1723 | dna, mammals, eggs
Title: In what circumstances does a mammalian egg copy its DNA? In the 2nd episode of the new Cosmos series, the host Neil deGrasse Tyson shows how the white-furred bear could have evolved (reasonable scientific speculation, of course).
If you haven't seen that episode, here's the link. Great show, by the way.
So, it shows the bears eggs, and then goes on to show how there can happen an error in the DNA copying, that leads to the brown pigment production malfunction. Here's an excerpt from the subtitles text:
- great bears roamed the frozen wastes of Ireland.
- This might look like an ordinary bear,
- but something extraordinary is happening inside her.
- Something that will give rise to a new species.
- In order to see it, we'll need to descend down to a much smaller scale, to the cellular level, so that we can explore the bear's reproductive system.
..
- Those are some of her eggs.
- To see what's going on in one of them,
- we'll have to get even smaller.
- We'll have to shrink down to the molecular level.
..
- When a living cell divides in two,
- each one takes away with it a complete copy of the DNA.
- A specialized protein proofreads to make sure
- that only the right letters are accepted
- so that the DNA is accurately copied.
- But nobody's perfect.
- Occasionally, a proofreading error slips through,
- making a small, random change in the genetic instructions.
- A mutation has occurred in the bear's egg cell.
- A random event as tiny as this one can have consequences on a far grander scale.
- That mutation altered the gene that controls fur color.
- It will affect the production of dark pigment in the fur
- of the bear's offspring.
The following is multiple choice question (with options) to answer.
A polar bear is white because | [
"it's a lame Turkish professor in a third rate Pennsylvanian college",
"it's covered in polar snow ice",
"it wants to make a Grizzly bear jealous",
"its parents had white fur"
] | D | the coloration of fur is an inherited characteristic |
OpenBookQA | OpenBookQA-1724 | geology, mineralogy, minerals, weathering
To me, supergene has a specific meaning, it may be part of the weathering process in some locations, but weathering involves the breaking down of rocks due to: reactions with atmospheric gasses, water (usually rain), changes brought on by plants, bacteria wind and temperature.
My suggestion to use the term weathering or weathered.
The following is multiple choice question (with options) to answer.
Due to weathering | [
"large submarines are built",
"new bikes are raced",
"holes in the pathway",
"2nd story houses are built"
] | C | weathering means breaking down surface materials from larger whole into smaller pieces by weather |
OpenBookQA | OpenBookQA-1725 | homework-and-exercises, work, potential-energy
Title: Problem regarding finding work done This problem is given in my physics book. How much work will be done if anyone wants to stack up 12 bricks? Given that each brick is $10 cm$ high and each brick's mass is $2 kg$. ($g=9.8$)
Now in finding my answer I used the mass and height of all the bricks. But in my book they used the mass of all the bricks. But in using the height they used the height of only 11 bricks. So my result is $141.12 J$ and the book's result is $129.36 J$. Why is that? We are supposed to stack 12 bricks on one another. One brick is unmoved. The centre of mass of 11 bricks is 60 cm or 0.6m above initial level after stacking.
Now, the work done against the force of gravity is:
$W = mg \Delta h = 2(11)(9.8)(0.6) = 129.36J $
Another method is to calculate work done individually
$W = mg(\Delta h_1+\Delta h_2+\Delta h_3+\Delta h_4+\Delta h_5+\Delta h_6+\Delta h_7+\Delta h_8+\Delta h_9+\Delta h_{10}+\Delta h_{11})$
$\implies W = 2(9.8)(0.1+0.2+0.3+0.4+0.5+0.6+0.7+0.8+0.9+1+1.1)$
$\implies W = 129.36J$
The following is multiple choice question (with options) to answer.
If a brick is liquefied, then the weight of it | [
"is electrified",
"is static",
"is changed",
"is removed"
] | B | phase changes do not change mass |
OpenBookQA | OpenBookQA-1726 | magnetic-fields, earth
Title: Would a compass on its side point at the ground? From a point just north of the equator, A straight line to the Magnetic North would be through the earth. If a compass was turned on it's side, would the north pointing arrow point toward the ground along that straight line? A compass is usually used to find the direction of the horizontal magnetic field of Earth at that point. The needle of a compass is very light and thus its efficiency decreases when the compass is not in the horizontal plane at that point (due to gravity).Therefore, where the compass would point will become unpredictable. But, yes, in ideal conditions, the compass would point along the straight line joining that point to the north pole.
The following is multiple choice question (with options) to answer.
The floating arrow on a compass points in the direction of where a group of hikers came from. In which direction are the hikers hiking? | [
"south",
"west",
"east",
"north"
] | A | the floating arrow on a compass always points towards the north |
OpenBookQA | OpenBookQA-1727 | species-identification, botany, ecology, trees
Title: Identifying a shrub with unusual "many shoots" growth behavior While recently hiking in the southern mountains of New Hampshire, we came across a plant, and some of them were exhibiting what we interpreted to be a disease, or least unusual growth. On some of the nodes, there were a large number of extra stalks:
On each plant, the number and locations of these things varied, and not all of them had it. And we first assumed it was some ivy, or parasite, or separate plant, but it seemed pretty clear to us that it was coming right from the same branch.
We soon saw there were dead versions of this plant, and all of them had this "extra shoot" variation:
So we reasoned that no matter what this thing was -- natural variation or some kind of disease -- it was killing the plants.
Google image search was no help. It possibly identified the plant as a "viburnum", but was unable to help with the growth.
Anyone know what plant this is, or what this growth behavior is the result of? Possibly an example of a "Witch's Broom."
Witch's Broom is a deformity in plants (typically woody species) which typically causes dense patches of stems/shoots to grow from a single point on the plant. The name comes from the broom-like appearance of the stems.1
Witch's broom may be caused by many different types of organisms, including fungi, oomycetes, insects, mistletoe, dwarf mistletoes, mites, nematodes, phytoplasmas, or viruses.2
Sources:
1. Wikipedia
2. Book of the British Countryside. Pub. London : Drive Publications, (1973). p. 519
Image1. Gardeningknowhow.com
Image2. Iowa state University
The following is multiple choice question (with options) to answer.
A certain plant is in a field and bees suddenly surround it and climb all over it and fly away. The next year | [
"there are fewer total plants",
"that plant type rolls out",
"there is an earthquake",
"there is exactly two trees"
] | B | as the number of pollinators attracted to a flower increases , the ability of that flower to reproduce will increase |
OpenBookQA | OpenBookQA-1728 | particle-physics, neutrinos, antennas
Title: Can a neutrino antenna be made one day? I am wondering if it is theoretically possible that some kind of device/material could absorb neutrinos much better than everyday materials (preferably non-thermal absorption). This could enable a sort of neutrino antenna. How does an electromagnetic antenna work at the photon, quantum mechanical level? By inducing varying electric fields which induce accelerated charges which radiate coherently photons which build the classical electromagnetic wave.
The neutrino interacts with the weak interaction , is a fermion and can in no way be in a way similar to a photon, so cannot be regimented as the photon can.
The neutrino is produced in weak interactions, beta decays naturally, and in interactions in accelerators and cosmic rays. Let us see whether a neutrino beam that could be modulated is possible.
As in radioactivity they participate in three body decays there is no way to control their energy and direction so radioactively produced they cannot be coherent in any sense.
This leaves accelerators and cosmic rays. No way to control cosmic ray neutrinos of course.
If muon beams are produced in accelerators from pion decays, at the same time there will be a neutrino beam from the two body decay. If the production of the muon beam is modulated, the production of neutrinos will be modulated The problem will be on the detection side, since there are no receiving antennas other than huge detectors, like the OPERA.
What makes neutrinos attractive for gathering signals from the sun and stars, the weak interaction, prohibits any practical uses for the beam.
The following is multiple choice question (with options) to answer.
Radiaton can make something | [
"cooler",
"warmer",
"heavier",
"harder"
] | B | radiation is when heat is transferred through waves |
OpenBookQA | OpenBookQA-1729 | species-identification, zoology, entomology
Title: Species identification; clusters of big plump red bugs in Taipei I saw these red insects in Taipei near XinBeitou MRT station in the last week of April 2017, around lunch time. They were fairly active and would keep checking each other out with their antennae for a moment and then move on to the next. What struck me was the wide range of sizes and development in the groups. I didn't notice any feeding or mating that I could recognize, just a lot of walking around and checking each other out.
There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.
I've also included a screenshot from google maps so you can see the location and the trees growing in these concrete structures.
The body of the largest individual is probably 2.5 centimeters long. I'm fairly certain these true bugs belong to the species Leptocoris vicinus, and carry the nickname of "soapberry bugs", which is specific to the subfamily Serinethinae. They're quite common in urban areas of Southeast Asia, which coincides nicely with where you encountered them.
Also, you had mentioned,
There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.
Soapberry bugs, as well as many other types of insects, are able to freely congregate in large numbers, and in such exposed places, due to their bright coloration. Having such a bright color may indicate to some predators that the prey in consideration is toxic, a phenomenon referred to as aposematism.
source
source
And then, here's a map of their distribution, with Taipei holding marker #37. (source)
An interactive version of this map can be found here.
The following is multiple choice question (with options) to answer.
An example of an animal pollinator is | [
"Dogs",
"Leaves",
"Cape elephant sengis",
"Water"
] | C | pollination requires pollinating animals |
OpenBookQA | OpenBookQA-1730 | genetics, immunology, ecology, biodiversity, fitness
Title: What does genetic diversity in one species have to do with survival rate when an epidemic spreads? I was studying about genes, and soon remembered that the more diverse the genetics of one species, the less the chance of the species to go extinct from natural disaster.
One instance was an epidemic spreads.I don't fully understand why that happens, so I searched for it in Google and books, but all of them only told me that it is true, not why or how.
So my question is : why and how genetic diversity in one species affects the chance of the species's extinction?
I mean, for example, does it relate to antibodies or something else? Genetic diversity could be understood as a variation in alleles (gene variants) and their frequencies in a population. Due to these allelic variations, we would expect an inherent variability in individual genotypes (or genetic codes). Phenotypes (or traits) can and do vary with changes in underlying genotype. (In simple terms: if you change the underlying genetic code, it could result in changes to an individual's traits).
Changes in traits (e.g., color, size, speed, temperature regulation, mobility, etc.) could lead to a variation in energy conservation, survival, reproductive success, and ultimately fitness.
If any member of a population is more fit given a set of environmental circumstances, it is morel likely that they will survive and pass on their genes to subsequent generations.
You would benefit from reviewing evolution and natural selection. (Sexual selection and genetic drift are relevant, too, of course).
However, the environment and resulting ecologies are always changing, and so there is never an "endpoint" of this process. I.e., there's never a perfectly fit individual that will survive all future environmental changes better than all other variants. In fact, all organisms can only tolerate stressful environmental conditions to a point. (See, e.g., principle of allocation).
As a result, any given individual is limited in its ability to survive various environmental conditions, and no individual organism can survive all possible environmental conditions.
The following is multiple choice question (with options) to answer.
As number of organisms in a group increases , how will the chance of survival of each organism change? | [
"float",
"minimal change",
"augmented",
"lowered"
] | C | as number of organisms in a group increases , the chance of survival of each organism will increase |
OpenBookQA | OpenBookQA-1731 | food, psychology, health, taste, children
Title: Why do children prefer sweeter foods? As we get older, we tend to lose our sweet tooth and become more tolerant to bitter foods, like vegetables. However, I never understood how this works. Why is it that children prefer sweeter foods, even some that adults may consider "too sweet"? In fact, is there any reason they would also dislike bitter foods, even when they can be beneficial to their health?
This just seems bizarre to me that the body would start out craving sweets and lose this later on. Are only humans like this? Is there anything suggesting that younger animals prefer sweet foods too, but like them less as they get older? Does this have any biological advantage or is it just random? @Colombo explains one reason that I think is obvious. However, there has been some research done on this.
One other reason is because it would provide an evolutionary advantage in environments where calories are scarce. Also, sugar actually acts like a pain reliever. Studies show that giving sugar to babies and children during surgery act like a pain reliever.
The sweet tooth could be controlled by hormones secreted from the growing bones. Some common hormones like insulin also affect sensory centers in the brain. This explains why the sweet tooth goes away as an adult.
Reference
NPR -http://www.npr.org/sections/thesalt/2011/09/26/140753048/kids-sugar-cravings-might-be-biological
The following is multiple choice question (with options) to answer.
By hiding from creatures who crave the taste of their sweet flesh | [
"mice will be able to free Aslan",
"some mice are able to have offspring",
"predator missiles can hunt their target",
"a field of mice can die of disease"
] | B | avoiding predators has a positive impact on prey 's ability to reproduce |
OpenBookQA | OpenBookQA-1732 | optics, everyday-life, reflection, refraction, diffraction
Title: Why light rays gets scattered when it enters a translucent window pane? Consider the light source is the light post, outside the window of my house (Pic 1). When the rays from the light post enters through the window pane which is translucent gets scattered and forms a prominent design (Pic 2). Why does this happen? Your window is made of patterned glass, with regular changes in thickness. This is designed to diffuse light in order to prevent people outside from seeing what's inside (or you inside from seeing out; I don't know what your neighborhood is like).
In your case, the patterns are extremely regular, so that each incoming beam of light will get spread into a wide, regular pattern, which you'd see if you shone a laser pointer through the window onto a sheet of paper (perhaps moving the laser about a bit to catch every part of the pattern).
Here, though, you have light hitting the entire window in parallel beams (from that distant streetlight), and a single recipient (your eye). This means you'll see a bright point at every location where the patterned glass bends the beam to point exactly at your eye, which produces the pattern of light that you see.
The following is multiple choice question (with options) to answer.
A beam of sunlight strikes a stained glass window and | [
"colors all start disappearing",
"hues multiply through it",
"there are broken panes",
"fires are put out"
] | B | a prism refracts light |
OpenBookQA | OpenBookQA-1733 | I believe that the answer is 0.18.
geno3141 Jul 12, 2017
#2
+1129
+1
Geno, you have the hippo but you are missing the potamus.
(Using subscripted variables makes it easier to present and keep track of the relations.)
$$\small \text {Let A1 = {pass exam 1}, A2 = {pass exam 2}, A3 = {pass exam 3}, and A = {passes all three exams}. }\\$$
$$\text{Because }\ A^c_2\subset A^c, \; A^c_2\cap Ac=A^c_2 \\ \mathbb{P}(A^c_2) = \mathbb{P}(A^c_2|A^c_1)\; \cdot\; \mathbb{P}(A^c_1 +\mathbb{P}(A^c_2|A_1) \; \cdot\; \mathbb{P}(A_1) \leftarrow \small \text{Apply Total Probability Formula}\\ = (0 \cdot 0.1) + (0.2 \cdot 0.9) = 0.18 \\ \text {Then }\\ \mathbb{P}(A^c_2|A_c) = \dfrac {\mathbb{P}(A^c_2 \cap A^c)} {\mathbb{P}(A^c)}\\ = \dfrac {0.18}{0.496} = 0.363$$
GA
GingerAle Jul 12, 2017
edited by GingerAle Jul 12, 2017
#3
+1
Rhinoceros !!!!!!!
noun, plural rhinoceroses (especially collectively) rhinoceros.
1.
any of several large, thick-skinned, perissodactyl mammals of the family Rhinocerotidae, of Africa and India, having one or two upright horns on the snout: all rhinoceroses are endangered.
Guest Jul 12, 2017
#4
+92888
0
Thanks guest,
Yep, Ginger sure got that one wrong :)
Gino is definitely affiliated with rhinos, not hippos :))
The following is multiple choice question (with options) to answer.
An elephant on the plains and a diamondback in the desert will receive | [
"zero amounts of precipitation",
"equal amounts of precipitation",
"similar amounts of precipitation",
"different amounts of precipitation"
] | D | a grassland environment receives more rainfall than a desert |
OpenBookQA | OpenBookQA-1734 | evolution, ornithology, palaeontology
One thing those many, many bird and proto-bird fossils also made clear is that the traits of modern birds (feathers, wings, toothless beaks, etc) didn't evolve in a simple line from non-bird to bird. Many of those traits evolved convergently in several lineages, were lost in some, maybe regained in others, and feathers in particular turn out to be a widespread dinosaur feature that cannot be considered a uniquely bird trait anymore (unless we want to call T-rexes "birds"). Still, saying "beaks evolved several times" or "feathers evolved several times" doesn't mean that birds, let alone modern birds, evolved from several different ancestors. It can mean that the common ancestor of birds had lots of variously bird-like more-or-less distant cousins living around the same time.
The following is multiple choice question (with options) to answer.
Birds could use their beaks to | [
"swim",
"run",
"tidy up",
"shop"
] | C | birds with beaks of different shapes eat different foods |
OpenBookQA | OpenBookQA-1735 | electrostatics, electric-circuits, electricity, electric-current, charge-carrier
Title: Potential difference between two hollow spheres and amount of current flow If two Hollow Spheres with radius $r_1$ and $r_2$ have charge $q_1$ and $-q_2$ in them respectively(charges are evenly distributed in the surfaces).The spheres are separated by a distance d .Now We connect a conducting wire from one sphere to another.Then What will be the potential difference between the two ends of that wire and what will be the amount of current flow if the resistance is R in that wire(lets assume the amount of charges in each sphere always remain constant i.e. $q_1$ and $-q_2$)? Can we evaluate these things mathematically i.e. without using the voltmeter or ammeter?
Like, i was thinking of using $\frac{kq}{r} $ formula for calculating the potential at each end and then $V_A-V_B=IR$ to Calculate the amount of Current flow.Is that a right approach? The potential difference
Finding the potential difference is a bit more complicated than you suggested, if I interpreted the meaning of $k$, $q$ and $r$ in your formula correctly.
Before connecting the spheres, they effectively form a capacitor with some capacitance $C$. If $r_1 = r_2$, you can use a formula from wikipedia to calculate $C$, which then gives you the voltage (potential difference) as
$$
V = \frac 1C \frac{q_1+q_2}{2}~.
$$
If $r_1 \neq r_2$, you will have to solve the Poisson equation,
$$
\Delta \phi(\vec r) = - \frac{\rho(\vec r)}{\varepsilon_0}~,
$$
The following is multiple choice question (with options) to answer.
If two electrical conductors contact eachother, what will flow through them both? | [
"electrifying looks",
"lightning",
"water",
"wind"
] | B | if one electrical conductor contacts another electrical conductor then electricity will flow through both conductors |
OpenBookQA | OpenBookQA-1736 | cell-biology, nutrition, blood-circulation, liver
Title: How do nutrients get to the cells they need to get to? I understand the basics of digestion. I know that nutrients get absorbed by the microvilli, enter the bloodstream and travel to the liver but after all that, what is the biological mechanism that guides these nutrients to the proper receiving location? Broadly speaking, nutrients that enter the blood from the gut, and those that are released into the blood by the liver, are available to any cells that require them. So there is no "guiding to the correct location" in the sense that you suggest.
Lipids for example are present in the various lipoproteins and can be acquired from these by all cells. Iron is bound to transferrin, and any cell with transferrin receptors can internalise the transferrin and take the iron. Glucose is available in solution in the plasma, and free fatty acids are bound to serum albumin in the blood. During starvation the liver produces ketones ("ketone bodies") which are taken up by many different tissues/cell types.
The following is multiple choice question (with options) to answer.
For nutrients to be absorbed from food it needs to | [
"enter through the ears and exit through the toes",
"be breathed in through the lungs and expelled through the eyes",
"enter the rectum and be excreted out the mouth",
"enter the mouth and be expelled out the rectum"
] | D | the digestive system digests food for the body |
OpenBookQA | OpenBookQA-1737 | organic-chemistry, molecules, carbohydrates
Title: When oxygen is connected only to carbon, are then the oxygen and carbon connected with a double bond? My teacher showed us three molecules: a carbohydrate molecule, a protein molecule, and a lauric acid molecule. I noticed that, when an oxygen atom is connected to one carbon atom and isn't connected to any other atom, then the oxygen and carbon atoms are connected with a double bond. Is my hypothesis correct, and has anyone ever found it before? Over 150 years ago August Kekulé had a dream about how atoms might form molecules. You might find it interesting to read about it.
Chemistry is largely about valence, the number of connections that each atom is able to make with other atoms.
In the cases you are talking about, with co-valent bonds, you can imagine each carbon atom as having 4 arms reaching out, each oxygen having two arms, and each hydrogen having 1 arm.
If an oxygen atom is connected to only one other atom, then that connection must use both arms, holding hands with 2 of the carbon atom's arms (just as you noticed), forming a double bond.
The carbon's other two arms could be connected to another oxygen atom, forming CO2 (carbon dioxide), or to 2 Hydrogen atoms, forming CH2O (formaldehyde).
Or it could double bond to another carbon atom, which in turn has two more arms to connect to something else, such as C2H5OH (drinking alcohol).
Molecules based on carbon are so common and potentially so complicated, that there is a whole field (organic chemistry) based on it.
If you are at all interested in chemistry, the concept of valence will be essential to your understanding.
The following is multiple choice question (with options) to answer.
From 2008 to 2018, the concentration of single carbon molecules bonded with two oxygen molecules present in the air has dramatically | [
"sharply declined",
"grown",
"decreased",
"polluted public opinion"
] | B | carbon dioxide concentrations in the air have increased over the last decade dramatically |
OpenBookQA | OpenBookQA-1738 | a) Assuming that the ball starts with Joan,
what is the probability that she will have it back after 2 throws?
$\begin{array}{cccc} & \text{John} & \text{Joan} & \text{Kim} \\
\text{John} & 0 & \frac{1}{3} & \frac{2}{3} \\ \\[-4mm]
\text{Joan} & \frac{1}{2} & 0 & \frac{1}{2} \\ \\[-4mm]
Then: . $A^2 \;=\;\begin{pmatrix}\frac{1}{3} & \frac{1}{2} & \frac{1}{6} \\ \\[-4mm]
\frac{1}{8} & {\color{blue}\frac{13}{24}} & \frac{1}{3} \\ \\[-4mm]
\frac{3}{8} & \frac{1}{12} & \frac{13}{24} \end{pmatrix}$
Therefore, there is a $\tfrac{13}{24}$ probability that Joan will have the ball after 2 throws.
Correct!
b) Assuming that the ball starts with Kim,
what is the probability that Joan will have it after 3 throws?
We want $A^3.$
The following is multiple choice question (with options) to answer.
A person gently tosses a ball to a friend who misses the catch so the ball will | [
"meet the dirt",
"fall down dead",
"reach a cloud",
"reach new heights"
] | A | An example of hitting something is dropping an object onto that something |
OpenBookQA | OpenBookQA-1739 | organic-chemistry, combustion, environmental-chemistry, atmospheric-chemistry
I'm suspicious this may just be ethanol, but the manufacturer swears it isn't.
The advertised ratio is 1 oz to 12.5 gallons of fuel which is less than 0.1% (I believe they used double that in the tests). Too low to be ethanol anyway, right?
Follow-up:
I have confirmed that I was originally mistaken in that all measurements are ppm. I received a new copy of the original results, and $\ce{CxHy}$ and $\ce{CO2}$ are indeed measured in percent, rather than ppm. It was incorrectly rewritten in the report. The numbers are the same, though. With reference to the discussion in the question comments, this product does not appear to appreciably reduce carbon emissions in total. It does however appear to reduce carbon monoxide emissions. As carbon monoxide is a product of incomplete combustion, it is plausible that the additive is helping the fuel burn more completely. Broadly speaking, you would hope that the majority of the carbon in your exhaust gas would come out as carbon dioxide, which is 'merely' a greenhouse gas and not truly nasty like CO or PAHs. Prior to the advent of catalytic converters, carbon monoxide poisoning by vehicle exhaust was a much greater risk.
It should be noted that conservation of mass tells us some powerful things about what to expect from an engine - namely that the carbon that goes in to the engine as a component of fuel must come out as exhaust gasses, particulates, polycyclic aromatic hydrocarbons etc., or else be sequestered inside the engine (though the latter is achievable by putting a banana into the exhaust pipe, it is generally done as a prank).
Reduction of carbon emissions in general is achieved through obtaining more work per mass of fuel burnt, which, when coupled with the mass and other design features of the car confers the fuel efficiency. Unfortunately, the data provided don't tell us anything about that. The more complete burning of the fuel, evinced by the reduction of CO concentration in the exhaust gas does imply some increase in efficiency, however CO is a very small component of exhaust gas, indicating alongside the low concentration of unburnt hydrocarbons that the fuel is already burning virtually to completion.
The following is multiple choice question (with options) to answer.
A person will make ethanol out of all aside from | [
"salt",
"grain",
"corn",
"maize"
] | A | ethanol sometimes is made of corn |
OpenBookQA | OpenBookQA-1740 | rotation, habitable-zone, weather, astrobiology
One of the interesting historical facts of life on Earth, at least to me, is how long it took what we might consider advanced life to develop. One celled life in various forms was around for over 3 billion years but the first fossils are about 650 million years old. It took life a very long time on earth to get from too small to see to large enough to leave a footprint . . . but, I digress.
I agree 100%, one celled life or Tardegrades could live on a planet with no tilt or 90 degree tilt. Easy. Ocean life in general should be fine cause oceans are more adaptive. Evaporation keeps ocean surfaces colder than land gets during peak heat and while a completely frozen over ocean isn't great for life, cold oceans hold more oxygen and CO2 which can be good for life. Oceans also circulate as an effective means of temperature moderation and fish don't really care how windy it is or how much or little it rains. The tilt question, I think, is really just about life on land.
Land life could be more vulnerable to high wind, extreme temperature shifts, droughts or floods, which could be driven by greater axial tilt, but I find it hard to believe that Axial Tilt is the be-all and end all. Day length and year length are key factors too.
One point I agree with the article on, is that a close to 90 degree tilt might not be ideal with one part of the planet always facing the sun and the other part never facing it but outside of extreme tilts, I don't see why it would be a big deal.
A thick cloud cover, for example, reduces seasonal changes. There's a number of factors.
The following is multiple choice question (with options) to answer.
Because people require water to survive, it's good to live near | [
"a pond",
"a national park",
"a gravel pit",
"a desert"
] | A | a body of water is a source of water |
OpenBookQA | OpenBookQA-1741 | physical-chemistry
Title: Solution with salts Does a solution of water and NaCl increase its volume of the same amount of the volume of salt added? Thank you
Does the ions Na+ and Cl- taken separately ,occupy more space than the binded molecule? Suppose we take $100$g of an $x$% by weight solution of sodium chloride, so we have $x$g of salt and $100-x$g of water. The volume of $x$g of salt is:
$$ V_S = x/\rho_S $$
where $\rho_S$ is the density of solid salt. Likewise the volume of the water is:
$$ V_W = (100-x)/\rho_W $$
Suppose when we dissolve salt in water the volumes just add i.e.
$$ V_\text{total} = V_S + V_W = x/\rho_S + (100-x)/\rho_W $$
then the density of our $x$% salt solution would be:
$$ \rho_\text{sol}(x) = \frac{100}{x/\rho_S + (100-x)/\rho_W} \tag{1} $$
The density of salt is $2.165$g/cm$^3$, and we'll take the density of water to be $1$g/cm$^3$, so we can use equation (1) to calculate what the density would be if the volumes just added and we can compared this with the experimentally measured density. I did this in Excel and got:
$$\begin{matrix}
x & Equation (1) & Experimental & Constant Volume\\
0 & 1.000 & 1.000 & 1\\
0.5 & 1.003 & 1.002 & 1.005\\
1 & 1.005 & 1.005 & 1.01\\
2 & 1.011 & 1.013 & 1.02\\
3 & 1.016 & 1.020 & 1.03\\
4 & 1.022 & 1.027 & 1.04\\
5 & 1.028 & 1.034 & 1.05\\
The following is multiple choice question (with options) to answer.
adding salt to a solid decreases what? | [
"how much light it emits",
"how much sound it emits",
"the energy needed to harden",
"the speed it travels"
] | C | adding salt to a solid decreases the freezing point of that solid |
OpenBookQA | OpenBookQA-1742 | botany
Title: Do plants absorb toxins from the soil? Consider a plant like Aloe Vera that grows up in a toxic environment where the concentration of pesticides, and materials like lead, mercury, cadmium, arsenic etc is very high(e.g. Marshland dumping yard ). Would that mean that the extract from these plants would contain all these toxic elements. Not "all of them". But yes, plants suck up water from the soil, with everything dissolved in this water - nutrients, heavy metals, poisons. And also they breathe air, and absorb stuff via this route.
There probably are some toxins which will not enter the plant, because their molecules are too large and/or fragile. For example, should a plant root come in contact with snake venom, I cannot imagine that any venom will end up stored in the plant leaves.
Plants also have their own metabolism, so they will change/deactivate some toxins. I've seen claims that some plants "purify" formaldehyde, although I don't trust the sources enough to be sure of that.
But the smaller the poison molecule, and the less similar to stuff which is usually digested in nature, the more likely that it will enter the plant and stick around instead of being broken down. The heavy metals you mentioned are prime candidates. If they are present in the groundwater - or also lead from air pollution, before we banned leaded gasoline - they end up in plants, including food plants. And mushrooms are even more at risk.
Growing food near waste dumps is a known problem in farming, and sometimes makes the news, for example here:
http://bigstory.ap.org/article/mafia-toxic-waste-dumping-poisons-italy-farmlands
The following is multiple choice question (with options) to answer.
Plants in an incinerator would | [
"petrify",
"freeze",
"wilt",
"cremate"
] | D | fire destroys plants in an environment |
OpenBookQA | OpenBookQA-1743 | # Statistics of 7 game playoff series
Background: a friend of mine makes a hobby (as I imagine many do) of trying to predict hockey playoff outcomes. He tries to guess the winning team in each matchup, and the number of games needed to win (for anyone unfamiliar with NHL hockey a series is decided by a best of 7). His record this year after 3 rounds of play (8+4+2=14 best of 7 matchups) is 7 correct/7 incorrect for winning team and 4 correct/10 incorrect for number of games (he only considers the number of games correct if he also picked the winning team).
We got to joking that he's doing no better than blind guessing on the teams question, but that he's substantially beating the odds if one assumes that the probabilities for a 4, 5, 6 or 7 game series are equal (would expect a 12.5% success rate, he's at 28.5%).
This got us wondering what the odds actually are for each possible number of games. I think I've worked it out, but I want to tie up a few loose ends since part of my approach was brute-force scribbling on a big piece of paper. My basic assumption is that the outcome of every game is random with probability $\frac{1}{2}$ for a each team to win.
My conclusion is that:
$$\rm P(4\;games) = \frac{2}{2^4} = 12.5\%\\ P(5\;games) = \frac{8}{2^5} = 25\%\\ P(6\;games) = \frac{20}{2^6} = 31.25\%\\ P(7\;games) = \frac{40}{2^7} = 31.25\%$$
The following is multiple choice question (with options) to answer.
Where would it be most difficult to play a game of ice hockey? | [
"ice hockey arena",
"the moon",
"a frozen pond",
"an ice rink"
] | B | the moon 's surface contains many craters |
OpenBookQA | OpenBookQA-1744 | intelligence
There might of course also be recessive genes on the X-chromosome causing males, who has only one X-chromosome, to be smarter but genes that are not causing disease might not be so interesting to investigate from a medical point of view.
According to wikipedia there are 499 x-linked genes and the total number of "vaguely defined traits" are 983.
I would say that yes, as a man you inherit more genes from your mother than from you father affecting your intelligence due to the fact that some genes on your x-chromosome affect your intelligence. Whatever the 499 x-linked genes do, you could say that traits affected by those genes to a greater extent are determined by your mothers genes than by your fathers, if you are a male.
Technically you would of course also have to take the genes on the y-chromosome, which are much fewer, into account.
The following is multiple choice question (with options) to answer.
An inherited characteristic from my dad is | [
"the cat",
"a building",
"moles",
"the bike"
] | C | the shape of body parts is an inherited characteristic |
OpenBookQA | OpenBookQA-1745 | behaviour
Title: What happens to silverfish when we throw them out the window? I'll find a silverfish from time to time in my flat. I don't mind them but usually I catch them and throw them off the balcony (second story) into the bushes and lawn below.
I was wondering, since they seem to live in the water conduits in the house, if they can survive outside or if they die/get killed instantly.
Thx for your help! Silverfish prefer high humidity and warmth. Ctenolepismacalvum (Ritter, 1910) was recently found in Japan at a temperature of 20-30°C and 50-60% RH. As long as there are pieces of bark, wet grass or other organic or human-made structures that retain humidity after each raining event, the likelihood that they will survive long enough to complete their cycle is high.
They could face dessiccation if they are not able to find a damp spot in time, depending on their tolerance to it. However, it was not possible for me to find information about their dessiccation tolerance.
The Zygentoma (silverfish order) have high tolerance to low humidity and most of the species inhabit dry and hot environments (it's just a few that like humidity), which again makes me think that those silverfish propelled out the window will survive.
The following is multiple choice question (with options) to answer.
Fauna will have to flee if their home is | [
"prepared",
"having renovations done",
"being built",
"demolished"
] | D | if a habitat is destroyed then that habitat can not support animals |
OpenBookQA | OpenBookQA-1746 | electricity, electric-circuits, electric-current
I was wearing flip flops from the time I stripped off my neoprene wet suit at the car until the time I started getting shocked (my wife was wearing Birkenstocks).
I had been snorkeling for about an hour in the Pacific Ocean wearing a full body wet-suit, booties, and gloves (no hood).
I had been camping the night before and consumed quite a bit of Gatorade.
My wife had only been wearing a spring suit and gloves, no booties.
There was another receipt that had been left in the machine (maybe someone else had been shocked as well and decided it wasn't worth the risk of going after it?)
I can't think of anything else relevant. Any insights into what was going on here would be welcome. I tried calling the maintainers of the machine but couldn't get through (this was before I found out that I seemed to be the only one affected).
Thanks!
She tried touching the machine in various places, again nothing. I inadvertently touched her hand while she was touching the machine and then suddenly she felt it too.
From this it is evident you were a good conductor to the ground.
You later say :
We came back out 15 minutes later after drinking our hot chocolate and tried to reproduce the phenomenon with no luck.
So no charge was passing through you any longer?
15 minutes is too little a time to change your conductivity. It could be a combination of an intermittent fault in the circuit and your conductivity at that time. You should alert their maintenance to be on the safe side.
The following is multiple choice question (with options) to answer.
To protect yourself from blisters you may try | [
"a bandaid",
"fur",
"a rainbow",
"a chicken"
] | A | as the thickness of an object increases , the resistance to damage of that object will increase |
OpenBookQA | OpenBookQA-1747 | water, solubility
Title: Does CO2 dissolve in water? First of all not a homework question, but one day it suddenly popped into my head while opening a bottle of soda and accidentally leaving a glass out for a while.
I get that $\ce{CO2}$ in water is not the same as Carbonic acid, however this also raises the question if $\ce{CO2}$ can combine with water (It does so in acid rain in the atmosphere(I would guess normal temperature and pressure)), then shouldn't dissolved $\ce{CO2}$ just form carbonic acid and hence become unusable for aquatic plants? And also if Carbonic acid does form in the atmosphere ( Again,I would guess normal temperature and pressure (feel free to correct me!)), why does the fizzing happen in soda bottles when opened in the first place, should Carbonic acid be stable at normal conditions?
Please do note that I talk about $\ce{CO2}$ dissolving under normal temperature and pressure
I feel like I'm missing something super basic and obvious here and I just can't put a finger on it.
Thanks in advance! I want to extend Maurice's comment:
The amount of $\ce{CO2}$ dissolved in water is proportional to the outer pressure. At $\pu{20 °C}$, 1 liter water dissolves about $\pu{1.7 g}$ $\ce{CO2}$ at normal pressure (1 atm). If the pressure is twice as large, the amount of dissolved $\ce{CO2}$ is twice as much, $\pu{3.4 g}$.
To talk about solubility of gases in liquids, we take the help of Henry's Law which states that:
The amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid.
Mathematically,
$$\pu{S_g=k_HP_g^\circ}$$
where $\pu{S_g}$ is the solubility of the gas, $\pu{k_H}$ is the Henry's law
constant which is different for different gases and $\pu{P_g^\circ}$ is the
partial pressure of the gas.
The following is multiple choice question (with options) to answer.
A carbonated beverage contains dissolved what? | [
"steel",
"plastids",
"plastic",
"carbonic anhydride"
] | D | a carbonated beverage contains dissolved carbon dioxide |
OpenBookQA | OpenBookQA-1748 | botany, plant-physiology, plant-anatomy
It made me wonder if we are simulating the sun in a dark room for growing the plants with the help of red, blue, and a little bit of far-red light, what will happen to the plants if we keep the ideal conditions for which the plants carry out photosynthesis whole day? Does it affect its yield or the plants die out quick?
I am an engineering student working on indoor farming, my knowledge of botany is the same as a high school student. So if I am wrong please tell me. Ideal conditions for photosynthesis
You mention ideal conditions to carry out photosynthesis, I would just like to point out that this includes carbondioxide levels, temperature, and nutrients as well as light.
Flowering
As anongoodnurse mentions performance might be measured by blooming which, in most flowering plants, has a day-light related component. However, for general growth increasing daylight over the 'natural' day length can often increase yield.
Daylight Cycles
The important point to note is that plants do 'ramp up' at dawn getting ready to start photosynthesizing (for some plants with temporal photosynthesis mechanisms (see CAM photosynthesis) this can be even more important). The reason plants do this is because plants can suffer from 'photobleaching' which can be considered similar to sunburn in humans, if they are not ready for sunlight. Getting 'ready' can involve lots of things including opening stomata (pores) to let CO2 in, changing which metabolic pathways are active, and moving about chloroplasts inside cells. Plants 'figure out' how and when to ramp up based on circadian rhythms which work well on 24 hour clocks and slight changes over time. Thus 12 hrs to 16 hrs can be a big change, particularly if the change happens by lights coming on earlier. Additionally, the 24 hour 'clock' means that plants will do better with 18hr light then 6hrs dark cycles than 36hrs light 6 hrs dark, because the total cycle length should be about 24hrs.
Photosynthesis Side Effects
The following is multiple choice question (with options) to answer.
What purpose does a plant light serve? | [
"Comfort them",
"Mimic sunlight",
"Keep plants warm",
"Protect from bugs"
] | B | a plant light is used for help plants by mimicking sunlight |
OpenBookQA | OpenBookQA-1749 | Kudos [?]: 4 [2] , given: 0
Re: Good set of PS 2 [#permalink] 19 Oct 2009, 08:02
2
KUDOS
Bunuel wrote:
4. A contractor estimated that his 10-man crew could complete the construction in 110 days if there was no rain. (Assume the crew does not work on any rainy day and rain is the only factor that can deter the crew from working). However, on the 61-st day, after 5 days of rain, he hired 6 more people and finished the project early. If the job was done in 100 days, how many days after day 60 had rain?
(A) 4
(B) 5
(C) 6
(D) 7
(E) 8
This one was solved incorrectly:
Days to finish the job for 10 people 110 days.
On the 61-st day, after 5 days of rain --> 5 days was rain, 55 days they worked, thus completed 1/2 of the job, 1/2 is left (55 days of work for 10 people).
Then 6 more people was hired --> speed of construction increased by 1.6, days needed to finish 55/1.6=34.375, BUT after they were hired job was done in 100-60=40 days --> so 5 days rained. They needed MORE than 34 days to finish the job, so if it rained for 6 days they wouldn't be able to finish the job in 100(40) days.
I solved in a more easier way I think:
1) 10 man 110 days --> need for 1100 man.days
2) 55 days with 10 men --> 550 man.days
3) 40 days with 16 men --> 640 man.days
--> total man.days equals 1190 vs need for 1100 --> days of rain equals 90/16 max --> 5.625 --> rounded to 5
Senior Manager
Joined: 31 Aug 2009
Posts: 420
Location: Sydney, Australia
Followers: 6
Kudos [?]: 165 [1] , given: 20
The following is multiple choice question (with options) to answer.
To replenish the shade in a city that had been provided by trees that were felled by a storm, you must | [
"grow gills and live on a raft",
"use a large lawn mower",
"introduce replacement timber producers",
"get out your weed whacker"
] | C | a tree can be replaced by planting a new tree |
OpenBookQA | OpenBookQA-1750 | A. 1
B. 2
C. 4
D. 5
E. 6
After 17 trips, the worker has carried 17 x 4 = 68 jugs.
From those 68 jugs, 68/7 = 9 cartons have been filled, with 5 extra jugs remaining. So, the worker needs one more trip to carry 2 more jugs to fill the partially filled carton with those 2 jugs.
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A worker carries jugs of liquid soap from a production line to a packi [#permalink]
### Show Tags
15 Nov 2017, 19:26
AbdurRakib wrote:
A worker carries jugs of liquid soap from a production line to a packing area, carrying 4 jugs per trip. If the jugs are packed into cartons that hold 7 jugs each, how many jugs are needed to fill the last partially filled carton after the worker has made 17 trips?
A. 1
B. 2
C. 4
D. 5
E. 6
each trip fills 4/7 of carton
(17*4)/7 leaves a remainder of 5
7-5=2 more jugs needed
B
Manager
Joined: 08 Apr 2017
Posts: 68
Re: A worker carries jugs of liquid soap from a production line to a packi [#permalink]
### Show Tags
19 Nov 2017, 06:02
AbdurRakib wrote:
A worker carries jugs of liquid soap from a production line to a packing area, carrying 4 jugs per trip. If the jugs are packed into cartons that hold 7 jugs each, how many jugs are needed to fill the last partially filled carton after the worker has made 17 trips?
A. 1
B. 2
C. 4
D. 5
E. 6
The worker has finished 17 trips.
Hence the number of jugs transported = 17*4 = 68.
The following is multiple choice question (with options) to answer.
A bunch of seals are about to deliver and need to make sure they have returned to home for | [
"positive feedback",
"silly nonsense",
"magical purposes",
"reproductive behavior"
] | D | seals every year return to the same beaches to give birth |
OpenBookQA | OpenBookQA-1751 | zoology, bacteriology, virology, mycology, infectious-diseases
Title: Beneficial effects of the fungi of a termite mound on the diseases suffered by the termites My motivation to join this Biology Stack Exchange is the article by David Pride that I've read from the Spanish edition of Scientific American, that's Investigación y Ciencia. The article is [1], and I think that is a very good work from the author and editors of this popular science magazine.
Question. I would like to know if the fungi of a termite mound have beneficial effects on health (related to diseases caused by viruses or bacteria) for the termites that live in the termite mound.
I add that Wikipedia has the article Fungus, and what's I evoke with my Question, is about if some species of fungi could live with the termites inside the termite mound and have beneficial effects on the diseases suffered by the termites. I don't know if this question is in the literature, feel free to answer my question as a reference request if you know references answering my question.
References:
[1] David Pride, Los virus de nuestro cuerpo, Investigación y Ciencia, Febrero 2021, Nº 533, pages. 76-83. In at least one case termite cultivated fungus produce antibiotics that benefit the termites and protect them from dangerous fungus. Of course just the fungus acting as food is also a huge benefit to the termites.
https://www.nature.com/articles/srep03250
The following is multiple choice question (with options) to answer.
What has a positive impact on a living things health? | [
"dehydration",
"death",
"brawn",
"starvation"
] | C | being stronger usually has a positive impact on an living thing 's health |
OpenBookQA | OpenBookQA-1752 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
A sticky fluid made by insects from nector might kill a very young human because it | [
"contains uranium",
"is genetically modified",
"contains bees",
"contains botulism"
] | D | bacteria can cause people to become ill |
OpenBookQA | OpenBookQA-1753 | rocks, remote-sensing, archaeology, ground-truth
Together, #1, #2, and #3 tell us that it's probably early summer just after the river ice has broken up.
The tooth-like features in the left image are simply erosional remnants sticking out of the riverbank. They could be bedrock (not likely), ice wedges, unmelted permafrost, or simply dirt. They are on the outside of a meander, so the river is actively cutting into them, and so the river-facing faces are quite sheer and high compared to the slopes in between. The right side might be white because the conditions there had left the snow unmelted when the image was taken. And of course their shadows are longer because the river channel is at the bottom of the bluff.
If you use Google Maps or Earth to go downriver a bit (up and to the left), you will see similar features sticking out of the riverbank, but because they're at a different angle from the features in your image, the fact that they're natural is more readily apparent.
Although the terrain is much less regular on the right side of the image, again the long shadows tell the tale. There are some round lumps that may be pingoes. The shadow that looks like a man is just a coincidental jumble of shadows from the broken terrain. If you look closely at the lump that is supposed to be the "man" (which would technically be an inunnguaq) does not have any protrusions that correspond to the "arms". The "arms" are the shadow of a little cliff or shelf past the lump, which is overlapped by the lump's larger shadow.
It's similar in effect to the infamous misinterpretation of a Viking orbiter image of a natural feature on Mars as a "Face on Mars".
This is a good example of the complications of image interpretation, specifically, understanding the conditions under which the image was taken. It's also a good time to emphasize the importance of doing ground truth when interpreting images. So when you go there, let us know what you find.
The following is multiple choice question (with options) to answer.
Grooves in the ground are a sign of | [
"sink holes",
"erosion",
"water accumulation",
"high traffic"
] | B | soil loss causes grooves in soil |
OpenBookQA | OpenBookQA-1754 | earth-rotation, seasons, time
Title: Are the length of seasons the same globally? Is the length of time, say months, for each season the same all over the world or can it vary? As has been noted in a comment, it depends on how you define seasons (see https://earthscience.stackexchange.com/a/2603/111).
If seasons are defined in astronomical terms, then they have the same length everywhere on the planet. This is simply down to geometry.
However, the effects of astronomical seasons vary geographically in a number of ways. The magnitude of seasonal changes, for example changes in day/night lengths, is more pronounced in higher latitudes, so the effect of (for example) winter might be noticeable for a shorter time period in the tropics than the arctic, and hence some people might reasonably consider winter to be shorter there. There are other, less systematic variations that depend on local climate and weather. In weather terms, not everywhere in the world has the same 4-season cycle that temperate zones tend to experience - so when defining seasons in terms of observable effects one often has, for example, a wet season and a dry season rather than spring /summer /etc.
The following is multiple choice question (with options) to answer.
Seasons cause change to what? | [
"volcanic eruptions",
"moon cycles",
"prairies",
"planets orbit"
] | C | seasons cause change to the environment |
OpenBookQA | OpenBookQA-1755 | the-sun, solar-system, earth, temperature, weather
That Wikipedia quote mentioned that "change in day length is another factor". I have some info and graphs about that here.
The distance from the Earth to the Sun does have an effect on the climate, but it's fairly minor. Currently, the Earth is closest to the Sun (perihelion) in early January, around 10 days after the December solstice, during the northern hemisphere winter and southern hemisphere summer. That makes the southern summer a bit hotter than the northern summer. It also makes the southern summer a bit shorter, because the orbital speed is fastest near the perihelion. However, the climate in the southern hemisphere is strongly affected by the strong circumpolar ocean current around Antarctica, which keeps the southern oceans cold all year round. In the southern hemisphere, not many people live at higher latitudes than 40° because it's just too cold, but that latitude in the northern hemisphere is quite heavily populated.
I have some info about the perihelion here and here.
For what it's worth, here's a graph of the distance from the Earth to Sun and to the SSB, for 2022, with a 7 day timestep between the data points.
Plotting script from https://astronomy.stackexchange.com/a/49823/16685
Here's a plot spanning 1700 to 2200 (the same timespan as my Sun-SSB plot in the answer linked above), also with a 7 day timestep.
The following is multiple choice question (with options) to answer.
December is during the summer in the southern what? | [
"states",
"division",
"cities",
"counties"
] | B | December is during the summer in the southern hemisphere |
OpenBookQA | OpenBookQA-1756 | planets, orbital-motion, stars
Title: Could there be a star orbiting around a planet? I wonder if there ever could be a star (really small) which may orbit around a planet (really big)? One thing to keep in mind is that objects that are bound gravitationally actually revolve around each other around a point called a barycenter. The fact that the earth looks like its revolving around the sun is because the sun is much more massive and its radius is large enough that it encompasses the barycenter. This is a similar situation with the Earth and Moon. If there were three bodies, where two bodies were of similar size (like a binary star system plus a massive planet) then an analysis of three body systems shows that there are stable configurations where the objects will be in very complicated orbits where it would be difficult to say one orbits the other.
Update: The short answer is yes, it is possible when you look at the complete dynamical system, for the reasons stated above. More evidence of this can be found in the study of regular star orbits where very complicated orbits are possible and can be stable. Currently the cut off for classification of a planet and a brown dwarf is 13 Jupiter masses, which is arbitrary to some degree. The lightest main sequence stars have a mass of 75 Jupiters. This will put the barycenter well outside the radius of either body for binary systems.
A quick check of the two body system using the equation:
$$R = \dfrac{1}{m_1 + m_2}(m_1r_1 + m_2r_2)$$
Setting $m_1 = 75$, $r_1 = 1$, $m_2 = 13$, $r_2 = 2$ gives:
$$\dfrac{75 + 26}{75+13} = 1.147$$
Indicating a barycenter at roughly $\dfrac{1}{7}$ the distance between the objects. More bodies will cause more complicated orbits, where again, it would be difficult to say which object orbits which. It should be noted that if the system was composed of 3 objects, 2 of which had similar mass, it would be possible to develop a system that appears to have two larger objects orbiting a third smaller object. A quick check reveals:
The following is multiple choice question (with options) to answer.
If the Earth revolved around another planet instead of a star, what might it lack? | [
"continents",
"satellites",
"starry skies",
"seasons"
] | D | the Earth revolving around the Sun causes the seasons to change on its axis |
OpenBookQA | OpenBookQA-1757 | inorganic-chemistry
Title: How do I derive metallic aluminum without electricity? I'm laying the foundation for a project called 21st Century steampunk, where I figure out what the world would look like if electricity was never discovered.
I'm wondering if it's possible to derive usable metallic aluminum from naturally occurring substances without using the Hall–Héroult process. One method, which would also require a non-electrical heating source, involves reduction with carbon. Given a high enough temperature -- meaning over 2000°C -- carbon carries off the oxygen as carbon monoxide and leaves the aluminum behind. See Ref. [1](https://doi.org/10.1016/j.energy.2007.06.002), which includes the equilibrium composition calculation below.
Reference
M.Halmann, A.Frei, A.Steinfeld (2007)."Carbothermal reduction of alumina: Thermochemical equilibrium calculations and experimental investigation". Energy 32, Issue 12, December 2007, Pages 2420-2427. https://doi.org/10.1016/j.energy.2007.06.002
The following is multiple choice question (with options) to answer.
Once we use all the aluminum in the world we can get more by | [
"Impossible",
"Watering the grass",
"building a dam",
"Planting soda cans"
] | A | aluminum is a nonrenewable resource |
OpenBookQA | OpenBookQA-1758 | the-sun, coordinate
Title: Is the sun flipped on the other side of the world? As the orientation of the moon is different in the northern and the southern hemisphere, is the orientation of the sun different in both hemisphere?
Does a sunspot appearing in the Sun northern hemisphere from the Earth northern hemisphere will look as located in the Sun southern hemisphere from the Earth southern hemisphere ?
If I understand well, an equatorial mount can compensate for the Earth tilt, but how is possible to compensate from one hemisphere to the other one? Is the image flipped?
thank you! Yes, the orientation of the Sun will be different from the Earth's northern and southern hemisphere, just like your example of the Moon.
I would not say that a sunspot in the "northern" hemisphere would appear to be in the "southern" hemisphere just because of the change in orientation. North is fixed on the Sun and Moon, just like they are on the Earth. (If you turn a globe of the Earth "upside down", the northern and southern hemispheres do not switch, just the orientation."
The view through a telescope may change the orientation, but the directions North, South, East, and West on the Sun and Moon remain the same. The user of the telescope needs to determine which directions those are (up, down, left, right). It changes with the design of the telescope (reflector versus refractor) and the number of optical elements.
The following is multiple choice question (with options) to answer.
March in the northern hemisphere is what in the southern hemisphere? | [
"Spring",
"Summer",
"Winter",
"Fall"
] | D | winter in the Northern Hemisphere is during the summer in the Southern Hemisphere |
OpenBookQA | OpenBookQA-1759 | human-biology, physiology, metabolism
Thus, carbon dioxide (in the form of bicarbonate) is an obligate requiement for mammalian fatty acid biosynthesis, but no CO2-derived carbon is incorporated into fatty acids.
Carbon dioxide is also required for oxaloacetate formation from pyruvate. This reaction may be though of a method of 'filling up' a key Krebs Cycle intermediate (a so-called anapleurotic reaction). The enzyme here is pyruvate carboxylase and the substrates for the reaction are pyruvate, bicarbonate and ATP, with oxaloacetate being a key product. This enzyme also contains biotin and (like acetyl CoA carboxylase), CO2 becomes covalently bound to biotin during the reaction cycle.
Pyruvate-CoA carboxylase was discovered by Harland.G Wood and C. Werkman in bacteria (See here for a good reference on the early work on pyruvate carboxylase). Its discovery was very controversial because at the time it was thought that animal/bacterial cells could not 'fix' CO2; that is it was though that CO2 is only 'fixed' in photosynthesis. This discovery disproved that piece of dogmatism.
A third enzyme that requires CO2 as substrate (in the form of bicarbonate) is propionyl-CoA carboxylase. This enzyme occurs in mitochondria and functions in odd-chain fatty acid metabolism. It also contains biotin.
I have concentrated on some biochemical aspects of your question. The three enzymes mentioned, acety-CoA carboxylase, pyruvate carboxylase and propionyl-CoA carboxylase all require CO2 in the form of bicarbonate as substrate, all contain biotin, and (as far as I am aware) all play very central roles in mammalian metabolism. (They also all require ATP as substrate).
The following is multiple choice question (with options) to answer.
Carbon dioxide can be found in what goes through the | [
"neck",
"ears",
"eyes",
"brain"
] | A | carbon dioxide can be found in the air |
OpenBookQA | OpenBookQA-1760 | electromagnetism, electricity, electrons, atoms, voltage
1Actually, electrons are also small magnets themselves (they have an instrisic quantum-mechanical spin) and therefore are attracted to inhomogenic magnetic fields, but that's quite another issue.
2Actually, it would... but that's mostly relevant in the high-frequency-regime, i.e. bound electrons that jiggle back and forth very quickly.
The following is multiple choice question (with options) to answer.
What object would be most attracted to a magnet? | [
"A feather",
"A brush",
"A pillow",
"A zipper"
] | D | if a magnet is attracted to a metal then that magnet will stick to that metal |
OpenBookQA | OpenBookQA-1761 | # Thread: physics tourist & bear problem
1. ## physics tourist & bear problem
another easy one i think:
A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.5 m/s. The car is a distance d away. The bear is 27 m behind the tourist and running at 6.0 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
how many meters?
thanks alot.
2. Originally Posted by rcmango
another easy one i think:
A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.5 m/s. The car is a distance d away. The bear is 27 m behind the tourist and running at 6.0 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
how many meters?
thanks alot.
The maximum value of d is such that the bear gets to the car at the same time the tourist does.
So set up a coordinate system such that the bear is at the origin and positive x is in the direction from the bear to the tourist.
Both are moving at a constant speed. The bear has to cover 27 + d meters in the same time the tourist covers d meters.
So for the tourist:
[tex]d = v_t t = 3.5t[tex]
Thus
$t = \frac{d}{3.5}$
For the bear:
$27 + d = v_b t = 6 \left ( \frac{d}{3.5} \right )$
Now solve for d.
-Dan
3. Hello, rcmango!
Another approach . . .
A tourist being chased by an angry bear is running in a straight line
toward his car at a speed of 3.5 m/s. .The car is a distance $d$ meters away.
The bear is 27 meters behind the tourist and running at 6.0 m/s.
The tourist reaches the car safely.
What is the maximum possible value for $d$?
The tourist has a 27-meter headstart.
Relative to the tourist, the bear has a speed of 2.5 m/s.
To cover 27 meters, it takes the bear: . $\frac{27}{2.5} \:=\:10.8$ seconds.
The following is multiple choice question (with options) to answer.
A bear snacks on a tiny bird and the person watching this will know that the bear may be all aside from | [
"a herbivore",
"an omnivore",
"a carnivore",
"a predator"
] | A | if an animal eats another animal then that animal is a carnivore or omnivore or predator |
OpenBookQA | OpenBookQA-1762 | radiation
You see similar things happening here. The metal rod at the top of the lamp acts as a capacitive ground - given the very high voltage, a tiny charge will flow from the tip of the filament to the rod. There is a small amount of gas in the tube which is ionized and gives rise to the light you see. The electrons eventually bombard the metal "anode" and produce Bremsstrahlung - note that without the metal, you were getting a glow and no reading on the Geiger counter. There is a similar demonstration online which is more convincing in its use of conventional materials, but which otherwise shows many of the same phenomena.
It is almost certainly very inefficient. Most of the energy in an X-ray tube is converted to heat as the electrons burrow too deeply into the tungsten target for their radiation to escape- apart from the fact that only the most violent deceleration produces X-rays with high enough energy to penetrate the bulb and be detected.
I noticed that when the "alpha window" was removed, the reading in your video went up. Since there was also a biscuit tin and glass bulb in the way I suspect there was a lot more low energy radiation generated than was detected. Good stuff for skin cancer.
The experiment as shown should not be repeated. Not only were the HV precautions extremely poor, but so were the radiation safety precautions. Please don't try this at home...
The following is multiple choice question (with options) to answer.
A metal rod is sitting outside and soaks up a lot of energy from a star, so the metal | [
"cries",
"wiggles",
"sears",
"dies"
] | C | if a substance absorbs solar energy then that substance will increase in temperature |
OpenBookQA | OpenBookQA-1763 | power, estimation, combustion
eg assume 6 kWh/kg for a sample of dry wood.
10% moisture would displace $\rm10\% \times 6000\,Wh = 600\,Wh$ from a 1kg mass.
$\rm600\,Wh = 600 \times 3600 = 2.16\,MJ$.
Energy to heat 100 g water 10$^\circ$C say to
$\rm100\,^\circ C \simeq 4.3\,J/^\circ C/g \times (100\,^\circ C-10\,^\circ C) \times 100\,g \simeq 40\,kJ$.
Energy to vaporise 100g of water from
$100\,^\circ\,\rm C$ to steam = $\rm2260\,J/g\times100\,g = 226\,kJ$
Total energy loss due to vapourising 10% water = $266\,\rm kJ$ = 11%
Loss of energy from water replacing wood = $2160\,\rm kJ$ = 89%.
Total loss to water = $2.426\,\rm MJ$.
Energy loss % in 1 kg wood due to 10% moisture = $\rm2.426\.MJ/21.6\,MJ$ = 11.2%
Not taken into account is the "watergas" process whereby passing water vapour over hot carbon results in breakdown of the water into Hydrogen and Oxygen and re-re action to form CO and CO$_2$. The net energy effects of this process vary immensely with circumstance and are ignored here.
Based on Warm Homes technical report.
The following is multiple choice question (with options) to answer.
dry wood easily | [
"grows",
"freezes",
"shrinks",
"incinerates"
] | D | dry wood easily burns |
OpenBookQA | OpenBookQA-1764 | meteorology, atmosphere, carbon, co2, rain
Bear in mind that this assumes an enormous rainfall intensity, 100% CO2 saturation of the water and equilibrium chemical dynamics. After the raindrops hit the ground at least half of it will immediately re-evaporate back into the air, leaving, at absolute most, about 3% of the atmospheric CO2 leached out of the atmosphere that will be available to react with the soil, rock or biosphere. Also consider that this is but one of several important processes affecting CO2 transience, such as photosynthesis, respiration, volcanism, industrial pollution, etc. So the CO2 estimates that you read about are average values. Advection and turbulent air mixing should ensure that the CO2 regains approximately normal concentration within an hour or two after rainfall.
The following is multiple choice question (with options) to answer.
A puddle after a rain will eventually | [
"leave to town",
"jump for joy",
"recede from warmth",
"burn with acid"
] | C | An example of evaporation is a body of water drying up by absorbing heat energy |
OpenBookQA | OpenBookQA-1765 | protein-structure, structural-biology, protein-folding
I would conclude by noting that although the individual components of these cellular polyproteins interact with one another to cooperate in the biosynthesis, the flexibility they exhibit allows transfer of the growing substrate from one component to another.
The following is multiple choice question (with options) to answer.
An example of a flexible container could be | [
"A car",
"A bird",
"play dough",
"A building"
] | C | if a flexible container is pushed on then that container will change shape |
OpenBookQA | OpenBookQA-1766 | human-biology, reproduction, anthropology
Note: here is a link about multiple pregnancy : https://www.healthline.com/health/pregnancy/chances-of-having-twins#assisted-reproduction. 49 - 19 = 30
So the 1st Child would be 30 when the last children would be born, as long as the parents stay healthy and the mother delivers the child in a natural way (No Surgical Procedure to deliver the child) and the Mother has not had Menopause (Menopause usually happens around 50 Years of age) the sibling age gap would be very possible, but lets take a look at how many children the mother had, if I am correct they had about 16 Children, many people in countries that have a considerably low life expectancy have many children, lets take a look at the world record for most children born from one mother...a person named Valentina Vassilyev, gave birth to 69 Children! Thats a lot of children, so giving birth to 16 children with a 30 age gap should be very possible and realistic as well.
The following is multiple choice question (with options) to answer.
two women have a baby, it is unlikely to be | [
"their biological child",
"a human",
"formula fed",
"an adopted child"
] | A | two females can not usually reproduce with each other |
OpenBookQA | OpenBookQA-1767 | biochemistry, endocrinology, environment
Title: How quickly do estrogens break down in the environment? Of all the synthetic hormones we use, estrogens are probably the most common. They are used for birth control as well as hormone replacement therapy. This researcher also shows that there is plenty of it in milk because dairy cows are often pregnant while they are being milked.
Estrogen is a sturdy compound, very much like cholesterol. I was wondering if anyone had any idea how long it would survive in the environment, given that some people are concerned about it interrupting animals life cycles. How fast does it break down in the wild? Months to years - although the actual duration in a specific environment depends on the nature of that environment and is tied to oxygen level. Higher oxygen, faster degradation. Less oxygen, the estrogen molecules interconvert among various closely related molecules which hampers both their detection and their degradation.
For more info, please see: Environmental science: The hidden costs of flexible fertility (Nature 485, 441 (24 May 2012)) and this Science Daily article.
The following is multiple choice question (with options) to answer.
What environment is often green? | [
"tree filled",
"ice caps",
"city",
"desert"
] | A | a forest environment is often green in color |
OpenBookQA | OpenBookQA-1768 | reaction-mechanism, safety
Title: What are the consequences of mixing Ferric Chloride Solution, distilled vinegar, baking soda and water? I was attempting to etch and blade with a ferric chloride solution. I did not have enough so I filled a glass with vinegar and water (3 parts vinegar to 1 part water) then added 2 oz. of ferric chloride solution. I added baking soda later to neutralize the ferric chloride solution, but was met with a deep red foam. I quickly added more baking soda and flushed the solution down a deep sink in my basement. I rinsed out the sink and glass with water and continued to add baking soda to neutralize any ferric chloride solution that had been spread by the red foam. What reaction occurred and is this and do I need to worry about it? I suspect the red salt you are seeing is Iron (III) carbonate, which was likely created from, as you noted, the neutralization of aqueous Iron (III) chloride with Baking Soda (in excess?) per the reactions:
$\ce{FeCl3 (aq) + 3 NaHCO3 (aq)-> 3 NaCl (aq) + 2Fe(HCO₃)₃(aq)}$
$\ce{2Fe(HCO₃)₃ (aq) → Fe₂(CO₃)₃ (s) + 3H₂O (l) + 3CO₂ (g)}$
$\ce{2Fe(HCO₃)₃ + HAc (aq) → Fe₂(Ac)₃ (s) + 3H₂O (l) + 3CO₂ (g)}$
where the last reaction could also lead to Iron (III) acetate from the vinegar presence, which is also subject to further neutralization by the Baking Soda.
The following is multiple choice question (with options) to answer.
A chemical reaction to vinegar or to baking soda can be caused by adding | [
"air",
"bees",
"cola",
"sand"
] | C | baking soda can react chemically with vinegar |
OpenBookQA | OpenBookQA-1769 | geology, geophysics, climate-change, carbon-cycle
We can see here in white numbers the most significant pre-industrial sources and sinks (at ~1000 years time scales). We can see that humans produce 9 Gigatons of carbon per year (GtC/yr), due to that extra inflow, photosynthesis is taking 3 GtC/yr more than before, and the ocean is taking an extra 2 GtC/yr as well. However, that is not enough to counteract the 9 GtC/yr we produce, and that is increasing the amount of carbon in the atmosphere at 4 GtC/yr. This means the level in the atmospheric "bath tub" is still rising.
If we were to keep those 9 GtC/yr we produce stable (i.e. not increasing production in the future). The concentration of $\ce{CO2}$ in the atmosphere will rise to a level high enough that the sinks will match the sources, for example with plants taking 5 GtC/yr and the ocean 4 GtC/yr, that would nicely balance the production. But that new equilibrium atmospheric $\ce{CO2}$ concentration would be high enough to rise Earth's temperature several degrees and force a whole reorganization of the Earth's climates.
Finally, we have to say that some of these $\ce{CO2}$ intakes, like the oceanic one, don't come for free, and have their own nasty consequences, like ocean acidification.
The following is multiple choice question (with options) to answer.
There is more carbon dioxide in | [
"a forest",
"a garden",
"a park",
"a crowded airplane"
] | D | as the population of plants decreases , carbon in the atmosphere will increase |
OpenBookQA | OpenBookQA-1770 | newtonian-mechanics, forces, rotational-dynamics, reference-frames, torque
Of course, when the time constants of all of these spring is short, as it is with the kinds of interactions we are interested in here, this real behavior gets close and closer to a "rigid body" like behavior. Indeed, what we can show is that this "rigid body" style rotation is one example of what happens when you assume that physics is local. If you assume that a piece of the object only "knows" things in the neighborhood of that piece, you find there is no way to avoid rotation. To have the object translate directly away from you when you push off-center requires that far parts of the object instantly "know" the correct direction to travel.
The following is multiple choice question (with options) to answer.
As you go from farther away from an object to closer to it, the object will | [
"get smaller",
"hit you",
"die",
"get big"
] | D | as distance from an object decreases , that object will appear larger |
OpenBookQA | OpenBookQA-1771 | evolution, dna, natural-selection
It seems plausible to me that we (advanced life) could have a biological mechanism to "write" needed alterations into either our own DNA or our reproductive DNA over time, triggering the very specific evolutionary developments necessary to our survival without relying on random mutation.
My question:
Is this possible? Does any similar mechanism exist that we know of? If not, how can so many specific (advanced) evolutionary leaps be otherwise explained? This entire answer will be long, so read the short part first, then read the rest if you (or anyone else) is curious. Citations are included in the long section. I can include additional citations in the short section if needed.
Long Story Short
Your question touches on some common misconceptions about how the evolutionary process. Organisms don't "want" to evolve traits. Traits evolve through the biological processes of random mutation and natural selection.
Organisms do not "want" to evolve traits. (Well, OK, I'd love to evolve an extra pair of hands but that is not possible.) Natural selection works by modifying existing traits. Your turtle can stare all she wants at food out of reach but she will not evolve a longer neck. Instead, natural variation exists among neck lengths of the turtles because of variation of the genes that determine features related to overall boxy size. Those individuals with longer necks may be able to get a bit more food, live a little longer, and reproduce a little more. They will pass along their genes to their offspring, so perhaps more of their offspring will also have longer necks. Over many generations, the turtles may have somewhat longer necks.
A common misconception is that the traits of organisms are precisely adapted for a specific need. They are not, for a few reasons. First, natural selection occurs relative to the current environment. Adaptations that work well in one environment may not be so useful in another environment. Environments are rarely stable over evolutionary time so traits are subject to constant change.
Next, as mentioned above, natural selection can only work on what traits are present. While an extra set of arms would be handy, I am a tetrapod. My four appendages, along with the appendages of all other tetrapods, trace back to our common ancestor. The appendages of all tetrapods are modifications of that ancestral trait.
The following is multiple choice question (with options) to answer.
Adults that go through incomplete metamorphosis may have | [
"love",
"feelings",
"horns",
"attached flying contraptions"
] | D | incomplete metamorphosis is when an insect reaches the adult stage without being a pupa |
OpenBookQA | OpenBookQA-1772 | star, planet
Title: Why is it always planets orbiting stars? In our solar system, there are 8 planets orbiting a star, the Sun.
And I understand that there are about 500 confirmed solar systems out there.
But why is it always planets orbiting stars? Why can't it be several stars orbiting a planet, or a star orbiting a star? Why is a star by definition stationary as opposed to planets which are moving.
Of course, in that case, it wouldn't make much sense to call it a solar system, but still. "Why is a star by definition stationary as opposed to planets which are moving." This just isn't true. Both star and planets orbit a point in the system known as the barycenter (a.k.a. the center of mass of the system).
Because stars are much more massive, this barycenter is much closer to the center of the star than it is to the planets. Hence it appears to the casual observer that the less massive object orbits around the more massive object. In fact both objects orbit the barycenter. Like so:
The following diagram (seen on the wikipedia page above) shows the motion of the solar system barycenter with respect to the center of the Sun. Note that the barycenter is close to the center of the Sun, but often spends time outside the visible surface of the Sun. It follows this complicated path, mainly because of Jupiter but all the other planets make smaller contributions too.
The following is multiple choice question (with options) to answer.
what do planets orbit? | [
"asteroids",
"moons",
"burning hydrogen ball",
"they are orbitless"
] | C | planets orbit stars |
OpenBookQA | OpenBookQA-1773 | species-identification, zoology, ornithology
Title: Identification by tail feather I saw the remains of a bird today I did not recognize, and it was pretty mangled so it was hard to describe it. It was about the size of a robin. However, it had a dark brown mottled body like nothing I have ever seen. I have included below a tail feather from the bird which is 5 inches long. I am sure it is not a thrush or a woodcock or a kestrel. So what was it?
Location is Great Bay, Portsmouth, New Hampshire, United States. I believe this is a tail feather (or retrix) from an adult male eastern whip-poor-will (Antrostomus vociferus). See right image below (click to zoom):
.
Source: USFWS Forensics Laboratory
Details:
The brown, mottled appearance and the size (~12 cm) match that of the OP's specimen.
A great resource for exploring bird feathers: https://www.fws.gov/lab/featheratlas/
The whip-poor-will's breeding grounds include the OP's location (i.e., New Hampshire), and according to All About Birds this species could still be present even late in the year ("they seem to leave between early September and late November.").
Orange is breeding. Source: All About Birds.
The whip-poor-will is a medium sized bird and similar in size to an American robin.
Whip-poor-will: 22-26 cm ; Robin: 20-28 cm
Eastern whip-poor-will, (c) Paul Cools, source: inaturalist
The following is multiple choice question (with options) to answer.
An animal that clucks has | [
"four legs",
"fur",
"teeth",
"wings"
] | D | chickens cluck |
OpenBookQA | OpenBookQA-1774 | food-chemistry
popcorn (kernels)
honey (jar of)
sugar (most forms)
alcohol (spirits like vodka, whiskey)
dried beans, dried lentils
I would not be planning to eat any of these stored for 25 years myself. And in general I'd suggest testing the items before trying them after 25 years or more (if you feel you must).
I would not expect cans or glass or plastic bottles of soda to be in good shape after anything like 25 years. The plastic might not survive without degrading. The can and plastic might react with the liquid over that timescale and the glass would survive but I'd be less optimistic about a sugar laced chemical soup like soda or cola not undergoing some changes. Hard to say.
If you want more info on this try this website.
Will it be ok to drink it, if it won't explode?
I would not try it. At best it soda would be flat and possibly not taste the same (chemical changes over that timescale ?) and at worst it could actually be harmful.
Exploding seems very unlikely.
Also, what about Snickers or a hamburger in a ziploc package with air sucked out of it with vacuum cleaner?
Air isn't the issue. There are bacteria that will happily live (and increase in numbers) on what's in the food. Well, it is food, after all. There are bacteria that will survive refrigeration as well. Over the timescale you're talking about I'd say it's all bets are off territory.
So: will Snickers, Hamburger in a ziploc, Bottle (or can) of Cola, all not opened, go crazy in 25 years? In 50 years?
All of those could be dangerous over such a long time period, IMO. At the very least they'd taste bad and at worst they'd kill you if you consumed them.
If so, can they go out of their packages and ruin the contents of the time capsule? If not, will it be safe to consume one of them?
Depends on the packaging. Glass would last indefinitely baring physical force or extreme of hot and cold (which might possibly cause fatigue cracking). The other wrappers would last pretty well (structurally), but 25 years is way past their design intentions. It would be a dice throw.
The following is multiple choice question (with options) to answer.
What do you have if you throw chocolate chips, peanuts, coconut, and dried strawberry into a bag? | [
"recipe for dynamite",
"a trail mix",
"a birthday cake",
"a cookie recipe"
] | B | An example of a mixture is clay mixed together |
OpenBookQA | OpenBookQA-1775 | Anyway, those highest points tend to be saddles. The very, very highest point-- where's that in Alaska or somewhere-- that's a max, of course, by definition. But there are a lot of saddle points in other places. And those would be maxima of minima or minima of maxima.
Good. I'm stopping there. We might see this again when we start gradient descent. But at least, because saddle points don't come up much in teaching calculus, I thought that was good.
OK, second point is models, Lab 3, and projects, anything you'd like to ask about projects. So, please, this is your chance to ask. You could also ask by email. If you have suggested or idea for our project, let me encourage you or a team to work on it or just yourself.
And if you want to think, OK, shall I get some feedback of does this sound sensible? Any suggestions? Send me an email. I'd be happy to-- of course, I'm a total beginner here, too. When I created this Lab 3, I was like desperate, not for model 1. For model 1, have you looked at-- it's reached Stellar. And it's only one printed page. Have people had a look at this?
So I'll just repeat quickly. Model 1 is an example where of overfitting. And what's going on with model 1? So model 1 says take-- 5 would be enough, but I probably said 10 or something. So I'll make it six points. And put a curve through them. So if you put a curve-- and the curve is going to be a polynomial.
So we're going to set a fit by polynomial. Everybody knows polynomial is C0 plus C1x plus whatever CK x to the K, let's say. For K equals 0-- well, I don't know if I even ask 0. That would be the best straight line. That would run along the average.
K equal to 1, that would be a straight line fit. And you would compute that by least squares, because of course no straight line is going to go through all the points. You're going to have some error by least squares.
The following is multiple choice question (with options) to answer.
Plateaus are typically | [
"Where dogs live",
"frequented by lightening",
"Have more rivers",
"Where cats live"
] | B | a plateau is formed by a buildup of cooled lava |
OpenBookQA | OpenBookQA-1776 | java, beginner, object-oriented, game, android
public class MainActivity extends AppCompatActivity {
private Button buttonStart;
private ImageButton rotateButton;
private ImageButton rightButton;
private ImageButton downButton;
private ImageButton leftButton;
private TextView pointTextView;
private TextView highscoreLevelTextView;
private TextView currentLevelTextView;
private Tetris tetris;
private NextPieceView nextPieceView;
private boolean pause = true;
private MediaPlayer mediaPlayer;
private int stopMediaplayer;
private GameBoard gameBoard = new GameBoard();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mediaPlayer = new MediaPlayer();
try {
mediaPlayer.setDataSource( this, Uri.parse("android.resource://com.example.admin.tetris/raw/tetrismusik"));
mediaPlayer.prepare();
} catch (Exception e) {e.printStackTrace();}
buttonStart = (Button) findViewById(R.id.buttonstart);
rotateButton = (ImageButton) findViewById(R.id.rotateButton);
rightButton = (ImageButton) findViewById(R.id.rightButton);
downButton = (ImageButton) findViewById(R.id.downButton);
leftButton = (ImageButton) findViewById(R.id.leftButton);
pointTextView = (TextView) findViewById(R.id.textViewPunkte);
highscoreLevelTextView= (TextView) findViewById(R.id.textViewHighscore);
currentLevelTextView = (TextView) findViewById(R.id.levelText);
The following is multiple choice question (with options) to answer.
Pressing the power button on an mp3 player | [
"turns on the dishwasher",
"switches a simple series circuit on or off",
"fills the bathtub with water",
"turns on the microwave"
] | B | when a switch in a simple series circuit is closed , electricity will flow through the circuit |
OpenBookQA | OpenBookQA-1777 | atmosphere, geography
Title: How much atmoshphere is there compared to land and water We know our earth has 71% water and 29% land, but compared to that land and water, how much air do we have in our atmosphere?
I mean:
How big is our atmosphere
Is there any increase or decrease in the amount of atmosphere over time
Is there any change in percentage of oxygen over time 71% of Earth's surface is covered with water and 29% land.
Thinking in that regard, that's saying that on 29% of Earth's "surface" locations you have land below your feet, and in 71% of the locations, you have water. So to continue in such terms, you'd then ask... ok, what percentage of Earth's surface locations would have air above them!?! Well that's all of them. So to if you're comparing it with those percentages, I guess you'd have to say it's another 100%. Or, if we put them together into a full 3-dimensional surroundings at the surface, well it'd basically be 50% air, 36% water, 14% land.
But to compare how much of each there REALLY is, you need to include depth, getting some sort of 3 dimensional understanding of it. But the picture that reveals is certainly not the picture we are used to from daily experience. From the values I was able to find:
In terms of the room each takes up, the volume:
Surface water (oceans+lakes+rivers, glaciers, etc) is 1.4 billion km³
The inside of the Earth is about 1 trillion = 1000 billion km³
For the atmosphere, as mentioned in comments, it's a little more difficult, as the gases only gradually give way to space. You find less and less gas as you go up, but there's no set spot where there is none, as some tiny amount is always floating off into space. So where do you draw the line? A commonly used boundary between the atmosphere and space is the Karman line. This would lead to a volume of 53 billion km³ (using Earth's radius = 6371 km). Note that only about half of that is in the troposphere and stratosphere, which are perhaps the familiar zones of the atmosphere where weather and the ozone layer (and 95% of air molecules) reside.
The following is multiple choice question (with options) to answer.
The atmosphere is made of 78% what? | [
"N",
"fire",
"clouds",
"wind"
] | A | the atmosphere is made of 78% nitrogen |
OpenBookQA | OpenBookQA-1778 | botany, plant-physiology, plant-anatomy
It made me wonder if we are simulating the sun in a dark room for growing the plants with the help of red, blue, and a little bit of far-red light, what will happen to the plants if we keep the ideal conditions for which the plants carry out photosynthesis whole day? Does it affect its yield or the plants die out quick?
I am an engineering student working on indoor farming, my knowledge of botany is the same as a high school student. So if I am wrong please tell me. Ideal conditions for photosynthesis
You mention ideal conditions to carry out photosynthesis, I would just like to point out that this includes carbondioxide levels, temperature, and nutrients as well as light.
Flowering
As anongoodnurse mentions performance might be measured by blooming which, in most flowering plants, has a day-light related component. However, for general growth increasing daylight over the 'natural' day length can often increase yield.
Daylight Cycles
The important point to note is that plants do 'ramp up' at dawn getting ready to start photosynthesizing (for some plants with temporal photosynthesis mechanisms (see CAM photosynthesis) this can be even more important). The reason plants do this is because plants can suffer from 'photobleaching' which can be considered similar to sunburn in humans, if they are not ready for sunlight. Getting 'ready' can involve lots of things including opening stomata (pores) to let CO2 in, changing which metabolic pathways are active, and moving about chloroplasts inside cells. Plants 'figure out' how and when to ramp up based on circadian rhythms which work well on 24 hour clocks and slight changes over time. Thus 12 hrs to 16 hrs can be a big change, particularly if the change happens by lights coming on earlier. Additionally, the 24 hour 'clock' means that plants will do better with 18hr light then 6hrs dark cycles than 36hrs light 6 hrs dark, because the total cycle length should be about 24hrs.
Photosynthesis Side Effects
The following is multiple choice question (with options) to answer.
A plant will be able to photosynthesize even better when | [
"it spreads out leaves flat",
"leaves leaves on fire",
"it makes leaves curl up",
"opens leaves inside out"
] | A | as flatness of a leaf increases , the amount of sunlight that leaf can absorb will increase |
OpenBookQA | OpenBookQA-1779 | everyday-chemistry, cleaning, minerals
Once you've got the crystal to the cleanliness you're happy with, you can polish it with powdered polish and a cloth, given time.
If instead of nice, angular crystals you're just trying to produce something like a smooth, rounded stone, after cleaning with water you can use a series of sandpapers (start at 60-80 grit and work up to ~400 grit) and polish to gradually smooth, then polish the stone by hand. This will clear away any deposits, but it will also change the surface of the stone itself. That might be acceptable to you if you've got something like a quartz river rock, and it will make a very nice end product. Take care to keep the stone wet while working, you don't want to breathe in rock dust if you don't have to.
The following is multiple choice question (with options) to answer.
Quartz can very easily damage | [
"smelted silica",
"granite",
"diamonds",
"steel"
] | A | quartz scratches glass easily |
OpenBookQA | OpenBookQA-1780 | particle-physics, astrophysics, education
Title: Are leptons, baryons and energy the only products of radioactive decay? I recently visited my child's elementary school to speak to a science classroom about rocks and minerals. While trying to explain what a crystal is, I got sloppy and mis-spoke that an atom was the smallest possible piece of matter (rather than an element!) I was quickly stopped and corrected by a 9-year-old that told me in fact atoms can be split into leptons and baryons. I told her she was right, and explained that if an atom of an element is divided it becomes a different element (overlooking isotopes!).
My knowledge of particle physics is limited and later I began wonder what I might be leaving out, that should not be left out, when talking of the types of 'ordinary matter' in nature. What happens in high-energy physics experiments aside. I know that there are other elementary particles besides leptons and baryons, photons are obviously everywhere.
But if we restrict the discussion to radioactive decay, fusion in stars, cosmic rays, is everything a lepton, baryon, or a photon? Your
What happens in high-energy physics experiments aside
partially contradicts your final question
But if we restrict the discussion to radioactive decay, fusion in stars, cosmic rays, is everything a lepton, baryon, or a photon?
Radioctive decay has as end products photons, leptons and baryons.
Fusion and cosmic rays are the realm of elementary particle physics, the energies involved much higher than the ones in natural radiaoctivity.
The reality of what "everything is made up of" depends on the energy with which you look at "everything". The answer is that everything is made up by the elementary particles, following the rules of the standard model, nuclear models, atomic models as the energies involved in "looking" at everything diminish. It is a compositeness built up consecutively. You might be interested in this answer to a similar question.
These are the elementary particles out of which all matter is formed. Every day matter involve mainly the first column and the last column . The two middle ones have been found in cosmic rays to start with and in accelerator experiments that led to the discovery of the standard model. They are particles that cannot come out from nuclear decays or fissions, i.e. "naturally" but need excess energy to materialize.
The following is multiple choice question (with options) to answer.
An organism is a source of what kind of matter? | [
"biotic",
"inanimate",
"dead",
"live action"
] | A | an organism is a source of organic matter |
OpenBookQA | OpenBookQA-1781 | sea-level, tides, seasons, flooding
Title: How was Venice flooded? If I understand this correctly, Venice was not flooded due to sudden rainfall causing rivers to overflow, but due to the high tides. These high tides were caused by an alignment of sun, which was expanding the waters of the oceans disproportionately on one hemisphere and moon, which shifted the center of gravity of the moon-earth system in such a way that water rose on the same hemisphere.
In the news articles that I see, they also mention strong winds. This would make sense. High baseline + waves = a lot of water in the city. But in these photos everything seems to be calm. No waves, no wind, just an abnormally high level of water:
https://www.theatlantic.com/photo/2018/10/venice-under-water/574396/?fbclid=IwAR1DWLs_W39ndpdLWLZ1f6wlDDw8ZJmcBqyVM555O9DL5a_DhuY0mPQDi38
For me this doesn't make any sense. If the winds subsided and the flooding was caused purely by tidal effects, which are astronomical events, shouldn't it have been predictable months, if not years in advance?
If the winds subsided and the flooding was caused purely by tidal effects, which are astronomical events, shouldn't it have been predictable months, if not years in advance?
The following is multiple choice question (with options) to answer.
What causes flooding? | [
"dryness",
"droughts",
"sunlight",
"deluges"
] | D | heavy rains cause flooding |
OpenBookQA | OpenBookQA-1782 | javascript, beginner, jquery, html, adventure-game
<div class="situation_text">
You walk away from the cave, to search for food. You find berries. Do you eat them or not?
</div>
<input type="button" class="situation_choice"
value="Eat the berries"
data-situation-target="eat_berries">
<input type="button" class="situation_choice"
value="Don't eat the berries"
data-situation-target="ignore_berries">
</div>
<div class="situation" data-situation="eat_berries">
<div class="situation_text">
You eat the berries.
</div>
</div>
<div class="situation" data-situation="ignore_berries">
<div class="situation_text">
You ignore the berries. You are still hungry.
</div>
</div>
</html>
The following is multiple choice question (with options) to answer.
A person eats some berries in them while camping in one location. In another location, miles away, they defecate outdoors. A result of this is | [
"seeds dying",
"berry pips relocating",
"crows hoarding",
"people coughing"
] | B | seed dispersal is when the seeds of a plant are spread from the parent plant to another area |
OpenBookQA | OpenBookQA-1783 | genetics
Additional response added as requested:
I see what you are getting at - why do children seem like such individual and unique things sometimes?
In sexual reproduction, the offspring are the product of the shuffling of the parent's genomes through meiosis, where the pairs of chromosomes we have are combined to make a single chromosome that will be half of the children genome.
This process can result in completely novel combinations of genes while conveying many likenesses from the parent. I would guesstimate that this is the major cause of the uniqueness of offspring/children.
Also in mammals there are some cell lines which splice families of genes which will cause offspring to be potentially quite different from either parent. Immune genes for instance are created from scratch from a bunch of genes that the parents give. Making each offspring unique but also the product of the parent's genetic repertoire. This can be significant as it affects health and also to some extent attraction - studies have shown that people who smell attractive to us are immunologically distinct from us.
@David mentions epigenetic variation, which is a more recent significant development. During our life, the germline (sperm/egg) DNA may be chemically labelled depending upon environmental conditions we experience. A famous example is experiencing famine conditions, which caused the children to be born on the small side amongst other effects. More recent studies have shown that this is a widespread mechanism to control cells in our body during our lifetime as well as communicate to our offspring how life is. It is expected that this labeling does not affect us forever - the epigenetic labels change over the course of a generation quite often (we believe).
The following is multiple choice question (with options) to answer.
Offspring receive genes from their parents via what? | [
"gene therapy",
"documents",
"double helix",
"paperwork"
] | C | offspring receive genes from their parents through DNA |
OpenBookQA | OpenBookQA-1784 | water, solubility
Title: Does CO2 dissolve in water? First of all not a homework question, but one day it suddenly popped into my head while opening a bottle of soda and accidentally leaving a glass out for a while.
I get that $\ce{CO2}$ in water is not the same as Carbonic acid, however this also raises the question if $\ce{CO2}$ can combine with water (It does so in acid rain in the atmosphere(I would guess normal temperature and pressure)), then shouldn't dissolved $\ce{CO2}$ just form carbonic acid and hence become unusable for aquatic plants? And also if Carbonic acid does form in the atmosphere ( Again,I would guess normal temperature and pressure (feel free to correct me!)), why does the fizzing happen in soda bottles when opened in the first place, should Carbonic acid be stable at normal conditions?
Please do note that I talk about $\ce{CO2}$ dissolving under normal temperature and pressure
I feel like I'm missing something super basic and obvious here and I just can't put a finger on it.
Thanks in advance! I want to extend Maurice's comment:
The amount of $\ce{CO2}$ dissolved in water is proportional to the outer pressure. At $\pu{20 °C}$, 1 liter water dissolves about $\pu{1.7 g}$ $\ce{CO2}$ at normal pressure (1 atm). If the pressure is twice as large, the amount of dissolved $\ce{CO2}$ is twice as much, $\pu{3.4 g}$.
To talk about solubility of gases in liquids, we take the help of Henry's Law which states that:
The amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid.
Mathematically,
$$\pu{S_g=k_HP_g^\circ}$$
where $\pu{S_g}$ is the solubility of the gas, $\pu{k_H}$ is the Henry's law
constant which is different for different gases and $\pu{P_g^\circ}$ is the
partial pressure of the gas.
The following is multiple choice question (with options) to answer.
What dissolves in water when combined? | [
"crystal carbohydrates",
"iron",
"oil",
"plastic"
] | A | sugar dissolves in water when they are combined |
OpenBookQA | OpenBookQA-1785 | zoology
From Scripture's research: “. . . a live frog can actually be boiled without a
movement if the water is heated slowly enough; in one experiment, the
temperature was raised at the rate of 0.002 degrees Celsius per
second, and the frog was found dead at the end of 2.5 hours without
having moved."
According to Dr. Karl S. Kruszelnicki (Australian scientist): "[T]he numbers just don’t seem right. If the water comes to a boil,
that means a final temperature of 100 degrees Celsius. In that case,
the frog would have to have been put into the water at 82 degrees
Celsius. Surely, the frog would have died immediately."
According to Dr. Victor H. Hutchinson (Herpetologist and Zoology Professor at University of Oklahoma):
"The legend is entirely incorrect! The 'critical thermal maxima' of many species of frogs have been
determined by several investigators. In this procedure, the water in
which a frog is submerged is heated gradually at about 2 degrees
Fahrenheit per minute. As the temperature of the water is gradually
increased, the frog will eventually become more and more active in
attempts to escape the heated water. If the container size and
opening allow the frog to jump out, it will do so."
Whit Gibbons (University of Georgia) says that there is an important message behind the false legend:
So where does that leave us with the boiling frog as a metaphor for
the human response to economic change or environmental degradation?
Well, it's not true that you can induce a frog to willingly remain in
boiling water by starting it off in cold water. But that does not
diminish the truth of the message that the accumulation of
imperceptible changes can have a significant effect on the economy and
the environment. We need to be aware of what changes are occurring and
to respond to them in a timely fashion. The metaphor lies in the
frog's ability to escape from the container: if there's no way out,
then the frog's fate is a foregone conclusion.
The following is multiple choice question (with options) to answer.
A frog will hibernate by burying itself in mud, freezing, then thawing again in the spring. The only of these that also go through a somewhat similar process in cold times is | [
"doves",
"grizzlies",
"rats",
"people"
] | B | An example of hibernation is a frog burying itself in mud |
OpenBookQA | OpenBookQA-1786 | zoology
Title: Are penguins plantigrade or digigrade? I'm trying to rig a 3D model of a penguin, but I don't know where to put the bones near the ankle because I can't tell if they're digigrade or plantigrade. Nearly all birds are digigrade, but penguins spend a lot of time walking and don't generally grasp or run with their talons. Plantigrade.
The penguins are highly specialized for their flightless aquatic
existence. The feet are located much farther back than those of other
birds, with the result that the bird carries itself mostly upright;
its walk can thus be described as plantigrade (i.e., on the soles).
The sole comprises the whole foot instead of just the toes, as in
other birds. The most notable characteristic of the group is the
transformation of the forelimb into a paddle. This is accompanied by a
body morphology particularly adapted to movement in a liquid medium.
The thoracic (rib) cage is well developed, and the sternum bears a
pronounced keel for the attachment of the pectoral muscles, which move
the flippers. The flipper has the same skeletal base as the wing of
flying birds but with its elements shortened and flattened, producing
a relatively rigid limb covered with very short feathers—an ideal
organ for rapid propulsion. The body plumage likewise consists of very
short feathers, which minimize friction and turbulence. The density of
the plumage and the layer of air that it retains provide almost
complete insulation of the body.
https://www.britannica.com/animal/penguin#ref3467
The following is multiple choice question (with options) to answer.
A bird such as a penguin can survive in arctic weather due to | [
"sunlight",
"bears",
"weather",
"feathers"
] | D | thick feathers can be used for keeping warm |
OpenBookQA | OpenBookQA-1787 | thermodynamics, electricity
Title: Removal of heat from a closed system using electricity I was thinking this morning about how heat could be removed from a system in such a way that it is stored for future use. My ideas are a form of thermo-electric system that converts heat into electricity which can be stored in batteries and capacitors. My question is, is it possible to use electricity as a medium to remove heat from a system? Using or generating the electricity is irrelevant, as long as more heat isn't generated. My goal is to remove heat without generating more heat. The closest existing solution to what you're looking for is probably Peltier cooling.
Of course Peltier coolers don't break the Second Law of Thermodynamics either: they are heat pumps, with a cold sink and a hot sink.
The following is multiple choice question (with options) to answer.
Ways to create reuseable energy could be: | [
"reading books",
"eating candy",
"bodies",
"touching things"
] | C | a solar panel converts sunlight into electricity |
OpenBookQA | OpenBookQA-1788 | cell-biology, hematology, red-blood-cell
Title: Why are red blood cells considered to be cells? Wikipedia states that a cell is
the basic structural, functional and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently.
It then goes on to state that
All cells (except red blood cells which lack a cell nucleus and most organelles to accommodate maximum space for hemoglobin) possess DNA.
Then why are red blood cells still considered cells, while they can't replicate? Is the definition on Wikipedia just a bad definition? Or are red blood cells wrongly considered cells, but remain so for historical reasons? Or are they considered cells for some other reason, such as this answer which states that red blood cells do contain a nucleus at some point? A very good question, and it is most likely because of the last option. It had a nucleus for part of its life. After the RBC jettisons its nucleus, it still remains very metabolically active for approximately 3 months. It maintains its cell membrane integrity, it metabolizes glucose, it interacts constantly with its environment, numerous cellular functions and structure remain intact... It is extremely specialized for a primary purpose, and no longer requires the nucleus to provide more proteins. It has limited capacity to heal from injury, so it has a limited life span.
Speculation: I wonder if it might lose the nucleus early on so that when it is destroyed in the spleen at the end of its life as RBCs are, the spleen macrophages are not overwhelmed with additional processing of nucleic acids? Macrophage type cells are already working hard in there to clear infectious agents and some immune cells from the blood.
The following is multiple choice question (with options) to answer.
Which type of cell must perform all life functions? | [
"candida",
"sea turtle",
"dragonfly",
"daisy"
] | A | if a cell can not specialize then that cell must perform all life functions |
OpenBookQA | OpenBookQA-1789 | organic-chemistry, acid-base
Title: What are the predominant acids in sphagnum peat moss? I'm trying to figure out what the predominant acidic substances in peat moss are. Peat moss is said to have a pH of approximately 4.0. So, I'm curious what is making it acidic.
I know not all acids bind to various elements in the same ways. So, I'm trying to find out which acids (and/or acidic salts) are present in peat moss in order to aid me in my research to discover approximately how long it might take to acidify soils with it compared with the traditional methods of adding various forms of sulfur to soil. You don't need to tell me how long it takes, by any means. I can do more research after I find out which acids or acidic salts are in peat moss, in what levels.
I'm not familiar with this particular SE site's customs. So, if this is the wrong place to ask, or if I used the wrong tag(s), feel free to let me know. I figured people might be more likely to know here than on Gardening and Landscaping, though. This 1992 article by Gagnon and Glime suggests that the ability of Sphagnum to lower pH depends on the presence of cations in the surrounding environment and is not (contrary to prevalent belief) due to organic acids in the plant itself. Here is a more recent article from New Phytologist amplifying that cation exchange is responsible for lowering of pH.
If you want to acidify soil using sphagnum/peat--assuming the authors are right--it's more important what cations you put into the soil. The sphagnum will then exchange them for $H^+,$ lowering the pH of the soil.
This does not mean there aren't organic acids in moss. You would have to look in specialized journals to determine what acids are found in the plant, but they are not necessarily very acidic and are, according to both articles, not the cause of acidity of the soil associated with the plants.
The following is multiple choice question (with options) to answer.
Peat may be beneficial to | [
"cats",
"birds",
"tomatoes",
"dolphins"
] | C | the formation of peat occurs at the bottom of swamps |
OpenBookQA | OpenBookQA-1790 | photography, software
Title: How to find which part of the sky a photo contains? I was taking some photo stacks yesterday, and I also took a plenty of random ones (pointed not at a specific object) too at 200mm.
However, I've ended with a shot but I have no idea where I pointed my camera at, and because of the narrow angle of 200mm, I'm lost without any guiding star/object.
This happened to me before too, so I was wondering whether there is a software or a website that I can upload a photo, and it will analyze the objects, cross match them with known objects and detect which part of the sky it is? Or is there a method that I can use to figure out by myself (remember that there are no well-known bright stars in the image, at least not that I can identify by myself)? Have you tried nova.astrometry.net?
They set up a web service for doing more or less what you're talking about.
The following is multiple choice question (with options) to answer.
To explore the regions of a super nova you will need | [
"take a picture",
"to look up",
"great vision",
"cylinder with mirrors"
] | D | detailed observation of celestial objects requires a telescope |
OpenBookQA | OpenBookQA-1791 | was in the air (between Point 1 and Point 3. A similar but more complete diagnostic test is being developed, but the subject of measurement uncertainty does not lend itself well to a right/wrong test, so even experts may disagree about which answers are "right" on such a test. 0 g and the masses to the left of the fulcrum are. c) Find the magnitude of the tension of the string between m2 and m3. If one of the balloons changes mass, we will be able to tell because the meter stick will 'tilt' towards the more massive object. The basic physics behind this activity is self-evident. They are both charged with charge q and both have mass m. nuts, washers, masses with hooks). One of the. The average deviation, = 0. 12 Static Equilibrium and Elasticity. This will either be provided to you in the problem statement, or it would have been previously determined from prior calculations. Similarly, a measurement like 0. Various hanging masses can be attached to the meter stick at various spots. Slide the supporting (knife-edge) clamp on the meter-stick and balance the meter stick alone on the support stand. More recently (1984), the Geneva Conference on Weights and Measures has defined the meter as the distance light travels, in a vacuum, in 1/299,792,458 seconds with time measured by a cesium-133 atomic. Make sure that the meter stick starts with 0 is at the bottom. Questions on parallel forces acting on a body are solved using the *principle of moment. Eventually, the object comes. Stanley Kowalski. F S F S is the normal reaction force at the. This is called the center of mass. Attach the 500-g spring scale at the far end of the meter stick so that the weight-bearing hook. Find F e, d e, F r, d r in gram force. Could a possible newfound carrier boson expand the definition of that framework? And it'll take XIV minutes flat. We indicate the pivot and attach five vectors representing the five forces along the line representing the meter stick, locating the forces with respect to the pivot. Use the 500-g spring balance to determine the mass of your “weights. Problem #6: Rolling and Torque 117. Hewitt, P. Two forces, both parallel to the tabletop, are applied to the stick in such a way that the net torque is zero. This is the
The following is multiple choice question (with options) to answer.
A large elephant is put on a device that can measure how much force is being applied based on its mass amount. That device is: | [
"atomic mass",
"a weighter",
"kilograms",
"a scale"
] | D | a scale is used for measuring weight |
OpenBookQA | OpenBookQA-1792 | virus
Assuming that you're not going splunking in bat inhabited caves in West Africa, it's safe to assume that what we are worried about is human to human transmission through infectious fluids. Ebola actual isn't that stable in water, so just soaking a surface in water and a little oil might help you out (if you don't have bleach handy). I want to be clear that I'm not recommending this, in reality you should just avoid contaminated objects. I think that we have clearly established that what we're really concerned about is infectious bodily fluid.
This leads me to the wonderful note by Jose Martin-Moreno titled "Is respiratory protection appropriate in the Ebola response?" I don't think I can express the problem better than he can, so hopefully I will be allowed a substantial quote:
This transmission [of ebola] occurs via close family contact or in
health-care settings, particularly when placing orotracheal intubation
or when caring for a patient who is vomiting or bleeding. Ebola is
rarely transmitted via an airborne route. Although these routes of
transmission are well known, most agencies, including governmental
agencies responsible for repatriating western patients, apply
infection-control measures appropriate for airborne diseases.
Excessive precautions could offer reassurance to those responding to
Ebola, yet complete respiratory protection is expensive,
uncomfortable, and unaffordable for countries that are the most
affected. Worse, such an approach suggests that the only defence is
individual protective equipment, which is inaccessible to the general
population. Moreover, the image of workers with spectacular protective
clothing might contribute to the panic in some communities. If this
leads people to flee affected areas it could increase the spread of
infection.
The following is multiple choice question (with options) to answer.
If one was to cease perspiration, what would they be most at risk for | [
"hypothermia",
"seizure",
"overheating",
"cramps"
] | C | when the body is hot , sweat is produced to cool the body |
OpenBookQA | OpenBookQA-1793 | evolution, vision, neurophysiology
Mid-reds with mid-greens
Blue-greens with grey and mid-pinks
Bright greens with yellows
Pale pinks with light grey
Mid-reds with mid-brown
Light blues with lilac
There are reports on the benefits of being red-green color blind under certain specific conditions. For example, Morgan et al. (1992) report that the identification of a target area with a different texture or orientation pattern was performed better by dichromats when the surfaces were painted with irrelevant colors. In other words, when color is simply a distractor and confuses the subject to focus on the task (i.e., texture or orientation discrimination), the lack of red-green color vision can actually be beneficial. This in turn could be interpreted as dichromatic vision being beneficial over trichromatic vision to detect color-camouflaged objects.
Reports on improved foraging of dichromats under low-lighting are debated, but cannot be excluded. The better camouflage-breaking performance of dichromats is, however, an established phenomenon (Cain et al., 2010).
During the Second World War it was suggested that color-deficient observers could often penetrate camouflage that deceived the normal observer. The idea has been a recurrent one, both with respect to military camouflage and with respect to the camouflage of the natural world (reviewed in Morgan et al. (1992)
Outlines, rather than colors, are responsible for pattern recognition. In the military, colorblind snipers and spotters are highly valued for these reasons (source: De Paul University). If you sit back far from your screen, look at the normal full-color picture on the left and compare it to the dichromatic picture on the right; the picture on the right appears at higher contrast in trichromats, but dichromats may not see any difference between the two:
Left: full-color image, right: dichromatic image. source: De Paul University
However, I think the dichromat trait is simply not selected against strongly and this would explain its existence more easily than finding reasons it would be selected for (Morgan et al., 1992).
References
- Cain et al., Biol Lett (2010); 6, 3–38
- Morgan et al., Proc R Soc B (1992); 248: 291-5
The following is multiple choice question (with options) to answer.
Due to camouflage, you are less likely to be able to see a polar bear in | [
"a church",
"the zoo",
"alaska",
"africa"
] | C | mimicry is used for avoiding predators by animals by camouflaging as a dangerous animal |
OpenBookQA | OpenBookQA-1794 | ecology
I have tried to find explanatory texts both in this and other books without any success so my question is how's this balanced state achieved in both types of successions (the answer is hinted in the first paragraph which I don't quite understand)?
Related to my last post. The author is saying that 1) Mature ecosystems tend to have a balance between production (=P) and use (=R, respiration) of biomass. This is actually tautological because the author would probably define a mature ecosystem as one where this is true (P=R).
If it starts out P > R, the autotrophs are dominant: more biomass is being produced than used up. It is possible, for a time, that P will increase as, for example, plants grow more leaves, but R is growing too, and there is an eventual limit on P, which at maximum depends on the light available to the ecosystem. As biomass grows, so does the amount of biomass to potentially decay, so eventually R will always catch up to P, until there is balance.
If it starts out P < R, that means you are using up biomass faster than you are creating it. This case is even simpler: you will gradually run out of biomass, and R will decrease.
In either case, when the author is talking about P = R, this is going to be in relative terms; there might still be variations between them, for example seasonal variation, but on average over years or decades you would expect P = R in a mature, stable ecosystem.
The following is multiple choice question (with options) to answer.
Plant population would fail to maintain it's size if | [
"fertilizer is applied",
"gets more sun",
"H2O depletes",
"grows"
] | C | as available water decreases , the population of plants will decrease |
OpenBookQA | OpenBookQA-1795 | components of the momentum vector in all spatial dimensions. To see how mass conservation places restrictions on the velocity field, consider the steady flow of fluid through a duct (that is, the inlet and outlet flows do not vary with time). Which has a parabolic form as expected. Electromagnetism G. from the perspective in a reference frame moving with the fluid. Let us consider a steady flow of an ideal fluid along a streamline and small element AB of the flowing fluid as shown in figure. It is possible to use the same system for all flows. The propagation of a tsunami can be described accurately by the shallow-water equations until the wave approaches the shore. The continuity equation is simply conservation of mass and Navier Stokes equation is simply momentum principle. Second, the nonlinear de-ments to form the linear macroscopic dispersion relation. By applying Newton’s 2 nd law to our elemental length of channel we have. Derivation of the Finite-Difference Equation 2-3 Following the conventions used in figure 2-1, the width of cells in the row direction, at a given column, j, is designated Δrj; the width of cells in the column direction at a given row, i, is designated Δci; and the thickness of cells in a given layer, k, is designated Δvk. It is possible to use the same system for all flows. All the examples of continuity equations below express the same idea. 10) where is defined as the water capacity function, and K(R) is another form of the unsaturated hydraulic conductivity function. 1 Derivation of shallow water equations. Fresnel equations for transmissivity and reflectivity At normal incidence At Brewster’s angle the reflectivity of the P-polarized field goes to zero The power reflectivity and transmissivity of a beam are 6. Fundamental equations 2/78 2 The equation of continuity 2. Let us consider a steady flow of an ideal fluid along a streamline and small element AB of the flowing fluid as shown in figure. Bernoulli's equation is based on the law of conservation of energy; the increased kinetic energy of a fluid is offset by a reduction of the "static energy" associated with pressure. elliptic equations. The equation is developed by adding up the rate at which mass is flowing in and out of a control volume, and setting the net in-flow equal to the rate
The following is multiple choice question (with options) to answer.
A level area near a steady flow of water is | [
"large salt-water ocean",
"a mountain peak",
"a fjord",
"a flood plain"
] | D | when a river floods , that river deposits sediment in flood plains |
OpenBookQA | OpenBookQA-1796 | evolution, mammals
Title: Why haven't land animals evolved beyond urination? It occurred to me (while urinating) that this would seem to be selected against because water is a scarce resource. Why are we constantly losing water we don't need to through urination? What is it about the chemistry of urine and the waste products eliminated that make urination necessary as opposed to eliminating them through defecation and recovering the water on the way out? It is probably true that toilets and other resting-ish area are always a great place to think about biology, I agree $\ddot \smile$.
Why do we urinate?
In short, urine contains the waste from our blood while defecation is just the stuff that we haven't digested. Kidneys are the organs responsible for draining wastes (mostly nitrogen-containing, or nitrogenous, wastes) from our blood.
Trade-off: energy cost vs. water loss
You're correct that the loss of water through urination is a considerable cost for an organism (especially those living in dry environments). But the amount of water used to excrete nitrogenous wastes is negatively correlated with the energy it costs to perform this excretion. In other words, there is a trade-off between water and energy loss during nitrogen excretion. Also, the question of toxicity is important.
Three ways to excrete nitrogenous wastes
Animals basically have three choices to excrete nitrogenous wastes:
Uric acid (excreted by uricotelic organisms)
Solid (crystal) with low water solubility
Low toxicity
Little water is needed
Lots of energy is needed
Ammonia (excreted by aminotelic organisms)
Highly soluble in water
High toxicity
Lots of water is needed to dilute it because of the toxicity
Not much energy is needed
Urea (excreted by ureotelic organisms)
Solid but highly soluble in water
"medium" amount of water is needed
"medium" toxicity
"medium" amount of energy is needed
The following is multiple choice question (with options) to answer.
The excretory system removes waste from what? | [
"fire",
"persons insides",
"oceans",
"body of paragraph"
] | B | the excretory system removes waste from the body |
OpenBookQA | OpenBookQA-1797 | Live Urban Brown Before And After, Excel Vba Create Pivot Table With Data Model, Waterproof Ipad Mini 4 Case, Double Trough Sink, Basic Warehousing Procedures, Temporary Wheelchair Ramp Rental, Will Frontline Still Work If My Cat Licks It, Text Detection In Images, Door Lever With Push Button Lock,
The following is multiple choice question (with options) to answer.
A puppy wakes up and needs to to for a walk. In order to have the ability to do this, he will require | [
"pebbles",
"lunch",
"toys",
"wheels"
] | B | an animal requires energy to move |
OpenBookQA | OpenBookQA-1798 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
Which is a pollinating creature? | [
"hyenas",
"lions",
"honey makers",
"rhinos"
] | C | A bee is a pollinating animal |
OpenBookQA | OpenBookQA-1799 | earth-history, planetary-science, meteorite, planetary-formation
The
measured concentration of HSEs in the Martian mantle is similar to the
Earth’s (Walker, 2009; Brandon et al., 2012).
Based on a conclusion made by Brandon et al. that
The relatively high HSE abundances in both planetary mantles likely cannot be accounted for by high pressure–temperature metal–silicate partitioning at the bases of magma oceans, as has been suggested for Earth. If the HSE were instead supplied by late accretion, this event must have occurred prior to the crystallization of the last martian magma ocean.
According to Raymond et al. the situation for for Venus and Mercury, the late veneer is modeled to have possibly affected their retrograde motion, but the authors admit that this is is speculative.
In the absence of sufficient samples from Mercury and Venus, it is modeling rather than sampling that the authors use to hypothesise the possible effect of the Late Veneer on them. Given Venus' size, it is likely that it, alongside Earth were the 'primary targets' of the late veneer bombardment.
Additional references:
Walker, R. J. 2009. Highly siderophile elements in the Earth, Moon and
Mars: Update and implications for planetary accretion and
differentiation. Chemie der Erde / Geochemistry 69, 101–125.
Walker, R. J., M. F. Horan, C. K. Shearer, and J. J. Papike 2004. Low
abundances of highly siderophile elements in the lunar mantle:
evidence for prolonged late accretion. Earth and Planetary Science
Letters 224, 399–413.
The following is multiple choice question (with options) to answer.
A large component of Earth's makeup is | [
"stoned",
"markers",
"diamonds",
"ground material"
] | D | Earth is made of rock |
OpenBookQA | OpenBookQA-1800 | geology, glaciology, geomorphology, ice-age, glaciation
Title: How old are Chile's fjords? Do we have any knowledge about the age of Chile's fjords, more specifically, those found near the Northern Patagonian Ice Field?
Is it reasonable to conclude that they were formed in Quaternary given the fact that there exist glaciers there at this point in time? The Quaternary is definitely a good guess. But it is difficult to answer your question because the "age of a fjord" is a rather ambiguous concept.
Also, I'll asume you are interested in the bedrock topography associated to the fjords, and not only the sea inlets (as in that case they would have formed very recently, just when the glaciers receded enough to allow the ocean water to take their place). With that said let's try to answer the question:
The fjords of western Patagonia are a feature created by the Pleistocene glaciations, therefore you can definitely say that the fjords as a feature of the landscape were formed during the Quaternary. However, they are in constant evolution, so you can arguably also say that the fjords as you see them today, were formed today.
Glacier erosion rates in Patagonia range roughly from a few tenths of millimeters to a few centimeters per year. Faster rates probably happening at the edges of the ice sheets were glacier basal sliding velocities are higher. Long term averages (~10 ka) are probably between 0.5 mm/yr and 1 mm/yr, meaning that in the 2.6 Ma of the Quaternary you would erode just about one to two kilometers. As some fjords can be much deeper than that (when measured from the mountain tops), it is clear that the fjords as a geographical feature are not in steady state, and they are now more dramatic than ever throughout the Quaternary.
The following is multiple choice question (with options) to answer.
A glacier moved through an area years and years ago, and scientists can tell this by | [
"looking at the moon",
"looking at the dogs",
"looking at the sky conditions",
"glancing at nearby stone"
] | D | glaciers cause scratches in rocks |
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