source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-701 | botany
Title: Greyish spots behind a peach's stone, what could they be? I'm sorry if it's a silly question, but what are those greyish spots behind the stone of this peach (or whatever this is)? What are they for? Are they safe to eat? The fruit is ok from the outside Callus can develop inside peaches (https://www.tasteofhome.com/article/peach-callus-tissue/), between the mesocarp and the endocarp. Callus is edible and harmless. It's a tissue composed of unorganised parenchyma cells, which in turn are multi-purpose cells that can be found in a number of "soft" tissues with metabolic purposes including, but not limited to, the mesocarp and the endosperm. Callus' main purpose is to seal damaged tissues, see for instance:
this blogpost that explains the difference between mold and callus in a peach where there actually is a mold infection (which you should not eat)
its counterpart where there is no mold, but a considerable amount of callus (way more than you have there) was produced because the stone had split open; this one would be safe to eat, once you've ascertained that there is no mold, although callus may contain pieces of hard tissue from the stone.
Small quantities of callus can appear as leftovers form older and smaller lesions.
The following is multiple choice question (with options) to answer.
Inside of a fruit is | [
"tiny hard pieces",
"small berries",
"worms",
"little sharp flecks"
] | A | fruit contains seeds |
OpenBookQA | OpenBookQA-702 | species-identification, botany
Title: Succulent weed identification There is a succulent-looking weed growing in a crack in my driveway. What is it?
Conditions: Dry, full sun, asphalt & gravel, no competition.
Date: 2018-07-16
Location: Toronto, Ontario, Canada
Size: 40cm x 40cm x 2cm This is Common purslane, Portulaca oleracea. It is used in salads, although it contains oxalic acid and there are poisenous plants resembling Purslane, see comment below.
https://en.m.wikipedia.org/wiki/Portulaca_oleracea
The following is multiple choice question (with options) to answer.
A weed will only live in the | [
"dirt",
"air",
"sink",
"house"
] | A | if a weed is pulled then that weed is destroyed |
OpenBookQA | OpenBookQA-703 | thermodynamics, everyday-life, condensation
Title: Condensed water inside a bottle So, I noticed that in a closed plastic bottle (say only less than half full) little droplets of water were condensed on one side of the internal surface. That was the side exposed to sun rays.
Why should water condense were sun rays hit more directly?
I would expect that water would condense on the (sensibly) colder portion of the internal surface.
I can see that water vapor inside the bottle maybe absorbs more energy from the sunrays and therefore tends to condense on the (colder) plastic surface.
But why on the side where sun hits more directly?
I think I observed the same with a 70 W lightbulb. My theory is also about the focusing of the light, but is opposite your idea in many ways:
The bottle and water both transmit light fairly well, so I see no reason to presume that the side nearer the sun is the warmer side. I am guessing that the focus of the reflected light off the far side of the bottle is the most important thing here. That area will be about R/2 away from the side of the bottle AWAY from the sun, and I hypothesize that that is the warmest area and therefore the rising warm air side of a convection cell in the gas above the water. That leaves the cooler condensing gas to flow back down the side of the bottle nearer the sun.
The following is multiple choice question (with options) to answer.
Taking it out into the sun can | [
"drain the power from a solar calculator",
"power down a solar calculator",
"short circuit a solar calculator",
"allow a solar calculator to come on"
] | D | if something is in the sunlight then that something will absorb solar energy |
OpenBookQA | OpenBookQA-704 | special-relativity, time, reference-frames
Title: When moving fast Time slows down Vs speeds up I was watching an old cartoon movie where a scientist makes a gadget, which when bound on the wrist, freezes the movement of the whole world. So, that one may do 100s of things in a single second. (The beagle boys later use the gadget to rob a whole bank in 1 second).
The scientist explains the working that the gadget helps in moving "very very fast". So fast that the person who wears it, sees the world, he finds everything frozen. As whatever he is doing is going on 1000s of times faster than the people in the world are doing.
The above explanation is quite logical and easily understandable actually.
So, with this logic, if movement occurs faster, time freezes. More the movement, more the time freezes.
With this thing in mind, how come then theory of relativity claims that
"moving faster may transport you ahead in time".
What I am assuming here is "transporting ahead in time" is probably something exactly opposite of "freezing the time". Am I right? Yes. Special Relativity satisfies your question somehow. Probably, there are many discussions in SE based on the topic. But, there are several cons I'd like to correct in your question...
If movement occurs faster, time freezes. More the movement, more the time freezes.
The following is multiple choice question (with options) to answer.
if something moves faster than before, it might have been affected by what? | [
"the application of water",
"the application of force",
"the application of light",
"none of these"
] | B | force causes the speed of an object to increase |
OpenBookQA | OpenBookQA-705 | python, python-3.x, tkinter
def slap(player):
print(player.name + " slapped.")
global slapped
if not slapped: #skips over logic if another slap has already arrived.
slapped = True
root.update()
global pile
#Check for valid slap conditions.
if pile[len(pile) - 1].value == 11 or len(pile) > 1 and (
pile[len(pile) - 1].value == pile[len(pile) - 2].value):
if player.name == "human":
messagebox.showinfo("Slap!", "You WON the slap!")
print("human takes pile")
#transfer the cards in pile to the pile of the plaer
for card in pile:
human.deck.append(card)
pile = []
else:
messagebox.showinfo("Slap!", "You LOST the slap!")
print("compy takes pile")
for card in pile:
compy.deck.append(card)
pile = []
else:
#handles the one card penalty for slapping at the wrong time.
print("bad slap")
if player.name == "human":
messagebox.showinfo("Slap!", "You slapped at the wrong time.")
pile.append(human.deck[0])
human.deck.remove(human.deck[0])
update_label()
root.update()
else:
messagebox.showinfo("Slap!", "Computer slapped at the wrong time.")
pile.append(compy.deck[0])
compy.deck.remove(compy.deck[0])
update_label()
root.update()
The following is multiple choice question (with options) to answer.
A boy smacks another child in the face. The child cries because | [
"it was harmed",
"it was sitting",
"it was happy",
"it was lonely"
] | A | harming something has a negative impact on that something |
OpenBookQA | OpenBookQA-706 | visible-light, atmospheric-science, sun
Title: Why is there less UV light on earth in winter? So I have often read that, at least in e.g. northern Europe, in the colder seasons, there is not enough UV (-B) light arriving from the sun, so many people have not enough vitamin-D from that.
At first I thought it was simply due to the sun "shining" for only a much shorter period of time in winter compared to summer and hence less possible exposure (not to mention that most of the skin area is covered then).
But I just had a thought coming to my mind, thinking about that in the mornings and evenings, we mostly see red light here, the higher end of the visible spectrum not getting through.
I am not familiar with the physics behind that phenomenon, but thought that the higher-end of the spectrum like the invisible UV light may not be getting through here for even longer parts of the day towards and away from high noon, and that in winter, the part of the day where UV gets through is maybe very narrow and that's why it's said not to be enough.
Is that correct? And how exactly does this work physically? The reddening of the sun has to do with Rayleigh scattering as the sun passes through more atmosphere. (see picture). This is in a sense, related to less energy but not the primary cause.
The reason we get less solar energy per square meter is that the angle of the sun in the sky affects how spread out the light is. (see updated picture). Ignoring atmospheric effects, it's the sin of the angle times peak energy. 90 degrees or directly overhead, figuring peak solar energy is 1,369 Watts per square meter (that also varies with distance), but the energy from the sun is mostly governed by the sin of the angle.
45 degrees: 1,369 * sin(45) W/m^2 or 71% of overhead or Zenith. 20 degrees above horizon, 1,369 * sin (20), just 34% of peak solar energy. Winter corresponds with the sun being lower in the sky, sunlight is more spread out. There is measurably less energy hitting the same area when the sun is low in the sky.
Passing through more atmosphere amplifies that somewhat, but the angle of the sun is the primary cause.
The following is multiple choice question (with options) to answer.
Sunlight can | [
"make eyes more visible",
"bounce from a rod",
"create a real problem",
"blind a garden gnome"
] | B | light enters the eye through the pupil |
OpenBookQA | OpenBookQA-707 | geology, crust, geobiology
Title: Does crustal thickness have anything to do with how life existed and sustained on Earth? The original question that was put on hold "If the crust were the thickest layer of Earth, what effect would its thickness have on organisms?" was actually one of those 'counterfactual question' found on my science book, and it was really just a 'reflect upon' question. And it's actually a hard one for me to answer since it's 'what if?'s. So by revising, it would still confuse some poeple, but I guess it's already specific on its own. But I still find it hard.
Follow up question:
And what if it ever was thicker than the mantle or the rest of Earth's layers, can the planet still sustain biological life? If the crust were the thickest layer or Earth, several things would happen:
It wouldn't be a "crust" any more, by definition. Because this is what a "crust" is: a thin layer on the exterior of something. However, if we assume that the mechanical properties of the crust (being cold and brittle etc) would extend deeper in the Earth, the following applies.
No mantle convection, or at least mantle convection weak enough to probably not affect the surface. Therefore, no volcanoes, no mountain building, no subduction, no recycling of volatile elements, no sub-seafloor hydrothermal vents.
If it's cold enough, the core probably solidified and there is no magnetic field.
A good example would be Mars. A planet hypothesised to have tectonic activity in the past, but not any more. The crust of Mars isn't the thickest layer (again - think of definitions), but it is thicker in absolute and relative terms when compared to Earth. I will leave the implications of "Marsifying" Earth on organisms for you to figure out.
The following is multiple choice question (with options) to answer.
One of the earth's layer's is it's crust. It can be found | [
"just above it's mantle",
"in the center of the earth",
"on top of the moon",
"close to the sun"
] | A | the mantle is located just below Earth 's crust |
OpenBookQA | OpenBookQA-708 | soil
An analogous hypothesis proposed by RUSSEL3 for increases in the number of bacteria after partial sterilization by heat, frost, or other means is that by such partial sterilization the protozoa are killed, thus permitting the unhindered development of bacteria which under normal conditions is held in check by protozoa.
BROWN and SMITH (loc. cit.) in their investigations dealt mainly with the physiological activities of bacteria under conditions of low temperature and frost, although they also made some determinations of the number of bacteria in frozen soil. Their principal conclusions regarding the ammonifying, nitrifying, denitrifying, and nitrogen fixing powers of frozen soils are as follows: (1) that "frozen soils possess a much greater ammonifying power than unfrozen soils"; (2) that "during the fall season, the ammonifying power of the soil increases until the temperature of the soil almost reaches zero, when a decrease occurs, and this is followed by a gradual increase and the ammonifying power of the soil reaches a maximum at the end of the frozen period"; (3) that "the nitrifying power of frozen soils is weak and shows no tendency to increase with extension of the frozen period"; (4) that "frozen soils possess a decided denitrifying power which seems to diminish with the continuance of the frozen period"; (5) that "during the fall season, the denitrifying power of the soil increases until the soil freezes, after which a decrease occurs"; (6) that "frozen soils possess a nitrogen fixing power which increases with the continuance of the frozen period, being independent of moderate changes in the moisture conditions, but restricted by large decreases in moisture"; and (7) that "in the fall, the nitrogen fixing power of the soil increases until the soil becomes frozen, which in almost ceases, after which a smaller nitrogen fixing power is established."
The following is multiple choice question (with options) to answer.
Soil quality is improved when | [
"rain water floods the land",
"organisms pass and rot away",
"small trees sprout up",
"microscopic insects infest the landscape"
] | B | decomposition increases the amount of nutrients in the soil |
OpenBookQA | OpenBookQA-709 | organic-chemistry, catalysis, green-chemistry
Title: How does the work that won the 2012 Sustainable Chemistry Award contribute to sustainable chemistry? I'm seeking a lay explanation for how the work of Dr Marc Taillefer that won the 2012 European Sustainable Chemistry Award, contributes to sustainable chemistry.
From the press release, Dr. Taillefer
is being recognised for his seminal contribution to the field of
homogeneously catalysed coupling reactions leading to C—C, C—N, C—O, C—P bonds. His team at
the Institut Charles Gerhardt, ICG (Montpellier, France) is investigating for a decade the
environmentally sustainable conversion of small molecules into more valuable substances
catalysed by copper and iron molecular complexes. This renaissance of “Ullmann type arylations” is now often used at the academic or industrial level and avoids the use of more expensive catalysts based on palladium.
The objectives of the award are (to quote from this press release) to:
Recognise individuals or small research groups which make an outstanding contribution to sustainable development by applying green and sustainable chemistry.
Promote innovation in chemistry and chemicals that will deliver clear improvements in the sustainable production and use of chemicals and chemical products.
Demonstrate that chemistry and chemicals can play a central role in delivering society’s needs, while minimizing and solving environmental problems. His work is about developping new catalysts based on copper and iron, to replace to traditional catalysts based on palladium. Copper and iron are both very common elements in nature, while palladium is considered a high supply risk (see the 2012 British Geological Survey risk list for details).
The new RSC Visual Elements Periodic Table can be used to check this kind of information.
The following is multiple choice question (with options) to answer.
To be environmentally friendly | [
"use your feet to pedal somewhere",
"hop in a sedan",
"put the pedal to the metal in a truck",
"ride a motorcycle around town"
] | A | riding a bike does not cause pollution |
OpenBookQA | OpenBookQA-710 | • $P_2$ will fly $\big[1-(d+r+y)\big]$ distance away from the airport in the counter-clockwise direction to meet up with $P_3$.
• At this point, $P_2$ will donate $z$ fuel to $P_3$.
• $P_2$ and $P_3$ will then both fly back $z$ distance, arriving at a distance of $1-d-r-y-z$ from the airport with no fuel.
• After refuelling at the airport, $P_1$ will fly the distance towards $P_2$ and $P_3$ and refund each of them for that much fuel. All three planes will then head back to the airport together.
From this, we must have
• $0 \leqslant s\leqslant d/3$: $P_1$ can fly $s$ distance forward and backwards, and refund $P_2$ for $s$ distance
• $z\geqslant 0$: cannot donate negative fuel
• $2x + 1-d-r-y \leqslant d+r+y$: $P_3$ must not run out of fuel before $P_2$ can reach it again
• $1-d-r-y - z \leqslant d/4$: $P_1$ can reach $P_2$ and $P_3$, refund them both, and the three of them will have enough fuel to head back to the airport
• $2x + 2s + 1-d-r-y - z\leqslant d+r+y + z$: $P_2$ and $P_3$ must not run out of fuel before $P_1$ can reach them again
Putting these together:
The following is multiple choice question (with options) to answer.
A car is stuck in a ditch, and requires the passengers of the vehicle to get out and push it back onto the road. Two of the three passengers push the car, and they struggle to gain any ground, but when the third passenger helps them | [
"the car struggles to move",
"the car gains ground rapidly",
"the car is stuck",
"the car is too heavy to push"
] | B | as force exerted on an object increases , distance travelled will increase |
OpenBookQA | OpenBookQA-711 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
In the desert at night, most animals that live there find that they require less | [
"liquid to consume",
"food to eat",
"warmth to sleep",
"packmates for hunting"
] | A | as temperature in an environment decreases , the amount of water an animal in that environment will lose will decrease |
OpenBookQA | OpenBookQA-712 | anatomy, scales
If this horse is 500 kg (a mid-range mass for horses), each leg would have to support 125 kg, compared to only 37.5 kg for a 75 kg adult. Why don't we see a corresponding difference in cross-section? Elephant, rhinoceros, &c all have much thicker legs in proportion. The answer, I think, lies in the fact that the animals you mention all evolved as cursorial animals (that is, they run to escape predators). Less mass in the lower leg means it swings easier, so the animal can run faster.
There are two things you're apparently not noticing in that picture. First, the the horse's lower leg is almost entirely bone (and some tendon), and it's bone that does the supporting. The propulsive power comes from the large muscles of the hip, thighs, and shoulders.
Second, the lower part of the leg (with the white wrappings) is not anatomically equivalent to the human's lower leg, but to the bones of the hand and foot. You can see this if you look closely at the rear leg in that picture. The femur, equivalent to the human's thigh, ends at the knee just above the belly line. Then the tibia extends about halfway down, ending at another joint which you might think is the knee, but which is called the 'hock' in horse-speak. The white-wrapped part is a metatarsal, equivalent to human foot bones, then there pastern bones equivalent to human toe bones, ending in the hoof/toenail.
So consider that you can, if reasonably fit, walk around on tiptoe without crushing your foot and toe bones, then imagine the end result of your ancestors having done this for the last several tens of millions of years :-)
PS: With horses, there is some effect from human selection, too. Racing & show breeds tend to have thin lower legs, draft horses & working breeds have proportionately thicker ones. My first horse, a thorobred/arab mix, had legs about as thick as my wrists (granted, I'm a fairly muscular guy); my current mustang, about the same height & weight, has legs about twice as thick.
The following is multiple choice question (with options) to answer.
For it to survive, the horse relied on its owner to bring it | [
"a harness",
"a lead.",
"grain",
"a saddle"
] | C | an animal requires nutrients for survival |
OpenBookQA | OpenBookQA-713 | evolution, biochemistry, plant-physiology, plant-anatomy, life
Title: Plants without bacteria? is it theoretically possible? I know from school, that all live on the Earth need bacteria as low-level "machines" that break down/extract/convert/produce chemical elements and combinations, other high-level organisms needed. But it is a natural way.
But is it possible to have a world with plants (without mammals or microorganisms and without bacteria) that could exist in the long term. Saying the atmosphere of these world has already enough nitrogen, oxygen and CO2, and of course there is water.
What could break this artificially created world with such conditions (say the world created not from low-level living structures)?
Could bacteria emerge in the world? This is the sort of question that should be considered from more than one perspective. Since this is speculation, take it as a given that there is a lot of 'what if' here.
I doubt most animals and plants can do entirely without bacteria - as you say most of the essential nutrients come from bacteria, who fix nitrogen. If only plants were left on earth, eventually the plants would use up all the nitrogen and they would have to find a way to fix more.
Can bacteria emerge from just a world of plants? I don't think viruses arise spontaneously, but since genomes often have viruses embedded in them, over the course of a billion years or so, its possible since bacteria and viruses continue to be impressed upon our genomes. Would it happen in time? Most would be skeptical whether that timing could work out.
In practice it would be hard to create a world like this. I would be interested to see whether you could sterilize the microorganisms off of seeds without killing the plant for instance. If you're asking about a small sterile environment with only plants, you could do it by adding the nutrients the plants need and giving them sunlight. Such self sustaining systems have been made with cyanobacteria and i'd be surprised if plants could not be included. But these are closed systems and judged by limited amounts of time, so whether this is an answer to your question is not clear. Here it looks like some water plants and fish have been done. If there was a plant that created CO₂ at an adequate rate its possible.
The following is multiple choice question (with options) to answer.
organic life requires certain things to grow such as | [
"nutritional values",
"zinc",
"acid",
"darkness"
] | A | a living thing requires nutrients to grow |
OpenBookQA | OpenBookQA-714 | species-identification, zoology, bone-biology, bone
Title: What is this bone from? This object showed up on my fire escape in New York city. It appears to be some kind of bone. It's a bit smaller than an adult human hand. What animal is it from? Given the size and thin/elongated ilia as well as the urban location, I think a domestic cat and/or a raccoon are likely candidates. I'm leaning toward cat.
Cat pelvis:
VCA Hospitals
Ventral view of domestic cat pelvis; Source: BoneID
Raccoon Pelvis
Anterior view of raccoon pelvis; Source: BoneID
I'm not an expert in differentiating these two species' bones. I will note that your specimen is more or less in between the sizes of these two species. Your size is probably closer to the raccoon, but a cat is just more likely given the location.
The most noticeable trait that stands out to me is the size/pointedness of the ischial tuberosity, which better matches that of the cat.
The following is multiple choice question (with options) to answer.
Which might you find in a zoo? | [
"a Sunda Colugo",
"a Sneezewort",
"a sousaphone",
"a Picasso"
] | A | some animals live in zoo exhibits |
OpenBookQA | OpenBookQA-715 | 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.
A pack of wolves eat the sheep before a grizzly bear can get to them, what have the wolves done to the bear? | [
"out competed",
"out lasted",
"out ran",
"out lived"
] | A | if an animal takes a resource from another animal then that animal competes for resources successfully |
OpenBookQA | OpenBookQA-716 | 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.
What rock is likely to be more mechanically weathered? | [
"a rock used to make fires",
"a rock traveling through space",
"a rock far below the ground",
"a rock is hit by the sun's rays"
] | A | mechanical weathering is when rocks are broken down by mechanical means |
OpenBookQA | OpenBookQA-717 | atmosphere, climate-change, thermodynamics, radiative-transfer
All of which have a compounding effect in the regional and to a lesser degree, global environment, that Chen et al. attribute to as being a cause of a 1-2K temperature rise in high altitude areas in Eurasia and North America and as a disrupting influence in global atmospheric circulation.
Edit 28/2/2016: There is an interesting blog post about a similar phenomenon: Dubai construction alters local climate
Additional references
Chen, B., and G.-Y. Shi, 2012: Estimation of the distribution
of global anthropogenic heat flux. Atmos. Oceanic
Sci. Lett., 5, 108–112.
The following is multiple choice question (with options) to answer.
What is an example of humans building houses in a ecosystem and causing change in the environment as a result? | [
"a dog house is placed in a fenced in back yard",
"a birdbath is placed in a park with a low squirrel population",
"a city is built over a park and deer lose their home",
"a small house is built in the forest and animals are fed there"
] | C | humans building homes in an ecosystem causes that environment to change |
OpenBookQA | OpenBookQA-718 | entomology
Title: Constantly wiggling moth pupa - will it emerge soon? Today I found a moth pupa in the soil in my garden in western Sweden. It's about 15 mm long.
I have found similar ones before, but this one is wiggling a lot more, even after I put it down and put a bit of dirt over it. It's been moving for more than an hour now, but less now than in the beginning.
I was hoping to see it emerge, but if it will take more than a day or so, I will probably put it back. So, what I'm wondering is if this wiggling is any indication of how soon it will emerge. Or if there are other ways to tell.
Update: an hour later it has stopped moving. Maybe it was just very disturbed by my presence. I'm keeping it in a jar with soil and a stick for climbing up on, and I'll decide what to do with it tomorrow.
Update: 12 hours later and it seems very still. But I'm letting the question remain since I really want to know if there are any signs to look for.
Final update: After 16 days it had turned almost black, and was still very active when handled.
And after 17 days this moth came out: I posted the same question on tumblr and got an answer:
It depends on the species. This one looks like a Noctuid. I’d give it
two weeks to a month or so. You may be able to see its wings showing
through the darkening pupal case when the time draws near! Just make
sure you give it somewhere to climb up and expand its wings when it
ecloses.
After keeping it until the moth emerged, I now know that wiggliness is not an indication of maturity, but turning dark is.
The following is multiple choice question (with options) to answer.
After a long time, a paw print may end up | [
"in water",
"on a tree",
"in a building",
"underground"
] | D | An example of a fossil is a paw print in rock |
OpenBookQA | OpenBookQA-719 | human-anatomy, muscles
Title: Contracting muscles in humans I study biology at school, and unfortunately for me, my program skips the muscles in humans chapter.
I know (and mainly, feel) that the movement in one direction isn't created by the same muscle as the movement in the opposite direction, e.g the Triceps ("front") and Biceps ("back").
I know that the triceps straightens the elbow, while the biceps contracts the elbow.
I also know that, instead of actually moving the arm, I can contract these two muscles (when I show off, for example...) without actually moving the arm. That area becomes hard. Both muscles, as I feel, are contracting. I cannot statically contract only one of them.
My question is whether this action is something "special", or simply both muscles working against each other, resulting in zero movement? The situation you are describing where muscles are situated on opposites sides of a joint and produce opposing movements is called "antagonism." Most joints are set up where one or more muscles on either sides will produce such movements (e.g., flexors vs. extensors). Here's a question about muscles without antagonists.
When you contract all the muscles crossing a joint (i.e., when you are "showing off"), the muscles balance each other. If not, the bones would move and the joint angles would change. So taking the elbow as an example, in the image below, Arnold is contracting the elbow flexors (biceps brachii, brachialis) as well as the elbow extensors (triceps brachii). In order for the bones to remain static, the forces must be equal and opposite.
The following is multiple choice question (with options) to answer.
Muscles pull on bones in order to move them; which is an example of that? | [
"shaking your head in frustration",
"rolling your eyes at someone",
"wiggling your tongue in your mouth",
"wrinkling your nose at a smell"
] | A | muscles pull bones to move the bones |
OpenBookQA | OpenBookQA-720 | 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.
Which would a carnivore eat? | [
"fiddleheads",
"ramps",
"dulse",
"blobfish"
] | D | carnivores only eat animals |
OpenBookQA | OpenBookQA-721 | moon, observational-astronomy, jupiter
Title: Is it possible that I just saw Jupiter's moons? Today at about 18:00 I was looking for Venus near the moon and I saw a short bright line. I thought that maybe I was seeing Venus' crescent but it was perpendicular to the crescent of the moon. I then noticed Venus very close to the moon and realised that the line is Jupiter. I can confirm the location was Jupiter in Stellarium, and I can confirm in Stellarium that the moons are in fact aligned in the direction that I saw the line. Is it possible that I caught a glimpse of the Jupiter-moons system as a line and not a point source? Maybe.
The Galilean moons are (barely) bright enough to be seen with the naked eye, but they're so close to the much brighter Jupiter that seeing them is at best very difficult (but easy with even low-powered binoculars). Jupiter is not currently at opposition (the closest it gets to Earth), so that's not ideal.
I've never seen them without binoculars or a telescope, but someone with very good eyes in excellent seeing conditions might be able to make them out. And the OP didn't see them individually, just "a bright line".
Try again if you get another opportunity. If you see the "bright line", try rotating your head. If the line rotates along with your head, you're seeing some other phenomenon, perhaps an irregularity in your eyes, or a reflection in your glasses or contact lenses if you wear them. If it doesn't rotate, I'd say there's a good chance you're really seeing the Galilean moons.
Another test would be to repeat the observation when all the moons are on the same side of Jupiter.
Just to gauge your eyesight, how many Pleiades are you able to see without binoculars or a telescope?
(And in case anyone is wondering, Jupiter's rings are not visible with the naked eye; they weren't even discovered until the Voyager 1 flyby in 1979.)
References:
http://en.wikipedia.org/wiki/Galilean_moons#Visibility
http://denisdutton.com/jupiter_moons.htm
The following is multiple choice question (with options) to answer.
You can see further from which of these locations on the moon? | [
"mountains",
"crater",
"buildings",
"surface"
] | A | the surface of the Moon contains mountains |
OpenBookQA | OpenBookQA-722 | 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 derive what from soil? | [
"pollination and germination",
"life sustaining substances",
"roots and oxygen",
"oxygen and argon"
] | B | soil contains nutrients for plants |
OpenBookQA | OpenBookQA-723 | organic-chemistry, alcohols, organophosphorus-compounds
Animal studies are consistent in reporting a decrease in the body weight of rats receiving ethanol solutions as the only source of liquids. Concentrations of ethanol as low as 5% (v/v), which are similar to the ethanol content of a Brazilian beer, or as high as 40% (v/v), solution similar to spirit drinks, are related to decreased body weight gain (9). Similar results have been reported for 20% (v/v) ethanol solution (10).
Different results have been obtained for malnourished animals. Da-Silva et al. (11), studying rats which had been treated with ethanol for 90 days, reported a significant weight gain by malnourished rats (50% food restriction) drinking a 20% (v/v) ethanol solution when compared to malnourished rats drinking water. A more recent study (12) reported improvement in somatic and motor development and a decrease in the mortality rate of the offspring of malnourished rats drinking low doses of ethanol (5%, v/v). These data suggest that malnourished rats can benefit from ethanol calories.
In summary, in spite of the large number of studies on the effects of ethanol in well-nourished animals and humans, there is still controversy about how well ethanol-derived calories can be utilized. Fewer studies are available about special physiological conditions such as malnutrition. Over the last few years, scientific research has mainly focused on obesity, an increasing problem in developed countries, which led us to the false belief that malnutrition was no longer a problem worth investigating. However, there are still 800 million malnourished people in the world (13). The decreasing interest of the scientific community in problems related to malnutrition has left many questions without an answer. Ethanol consumption and its consequences on the malnourished organism are among them.
In view of the importance of malnutrition in Brazil - 22% of the population or 40 million people are malnourished (14), as well as ethanol consumption and alcoholism - 11% of Brazilian population are alcoholics (15), the aim of the present study was to assess the use of ethanol calories in a dose/effect model by evaluating body weight before and after the installation of malnutrition.
The following is multiple choice question (with options) to answer.
What shows that as the amount of food an animal eats decreases , that organism will become thinner? | [
"outline of ribs is clearly visible on starving mammals",
"thin organisms are usually invertebrates",
"all thin animals lack proper nutrition",
"animals that have little food are dying"
] | A | as the amount of food an animal eats decreases , that organism will become thinner |
OpenBookQA | OpenBookQA-724 | magnetic-fields, magnetic-monopoles
Title: What happens to a magnetic needle inside a bar magnet? Imagine if we have a hollow bar magnet and we are trying to draw directions of magnetic field lines using a magnetic needle. The north of magnetic needle always points in the direction of the net magnetic field. Now, when we are inside the magnet, the north of the magnetic needle would point towards north and south towards the south - this is what is confusing me; this would mean the south of the magnetic needle remained attracted to the south and the north towards the north. Well, that predicts the direction of the magnetic field very well but it is quite opposite of the fundamental law of attraction. it is not against the law of attraction. If you divide the bar magnet there will be a south pol opposite the N of your needle
The following is multiple choice question (with options) to answer.
An attraction may be magnetic if | [
"two metals are placed together",
"substances find one another irresistible",
"nickel is in a metal rod",
"iron and nickel are in a bowl"
] | B | magnetic attraction pulls two objects together |
OpenBookQA | OpenBookQA-725 | planet, natural-satellites
Title: What is the official term for a relationship between a planet and its moons? Sorry if this is a dumb question, I could not find anything naming this in my astronomy books, and Google searches only seemed to show me pages about astrology, [sarc] because naturally, human relationships are influenced by celestial bodies. [/sarc]
I'm thinking along the lines of a parent-child relationship or a symbiotic relationship, but I couldn't find anything that specifically names this kind of relationship.
Is there an official term for this relationship? I don't believe there's an official term but there are a few familiar/common terms.
Parent Body/Satellite is one.
Central Object/Orbiting object or Central Object/Satellite.
Star/Planet or Planet/Moon imply one orbits the other. For a non orbiting Moon or Planet "Rogue" is used before their name.
A grey area comes into play when the two objects can be considered binary as opposed to one orbiting the other. Some people define a binary orbit as one where the barycenter is outside the body of the more massive object, but I don't like that definition because by that definition, Jupiter and the Sun are a binary system and the Sun weighs 1100 Jupiters. The Sun also has planets that don't meet that criteria, more distant than Jupiter.
Another problem with the Barycenter outside so it's binary argument is that when a star dies and goes white dwarf or even denser, then pretty much every planet now orbits a barycenter outside the star, but when it was a main sequence star, this wasn't the case. The orbits didn't change, just the size of the central object. That shouldn't change the definition of the orbital relationship. I think the Barycenter argument, while convenient, is highly flawed for that reason.
Pluto/Charon could be called a binary dwarf planet, but because Charon was likely created from a collision on the Body that's now Pluto, I think that's a poor definition and I think Charon should be called a moon or collision moon. That said, because four tiny moons orbit both Pluto and Charon, calling them a binary-system has some merit too. There's no neat and tidy way to make a precise dividing line, besides the barycenter, which is neat and tidy, but as I said above, inaccurate.
The following is multiple choice question (with options) to answer.
What best describes the relationship with the moon, Earth, and the sun? | [
"the Earth is absorbing sunlight",
"the moon is equidistant from the sun and Earth",
"the moon is a star",
"the sun travels around the Earth"
] | A | the moon reflects sunlight towards the Earth |
OpenBookQA | OpenBookQA-726 | botany, entomology
Title: What is this small white insect on my plants? Environment
I have a large amount of plants in an old industrial loft apartment.
I live in Rochester, New York.
I ship plants in from across the US, often exotic ones.
Observations
A few months ago, I noticed that two of my Sarracenia plants in my carnivorous plant bog were not growing anymore. Upon cutting them out as to not disrupt the live sphagnum moss grow medium, I noted that one of the insects in question had burrowed its way down into the core of the plant. I assume this to be the cause of the growing issue.
Today I noticed that one of my grape plants and Colocasia plants were covered in these bugs at different stages of growth. They range from white specs to ~3mm with the tail thing.
These insects appear sedentary. I have never seen one move, except when I cut the one out of the center of the plant.
Here is a picture of the bug, which was difficult to get due to the size.
Research
I looked through a variety of different "common insect" sites as well as some insect identification sites but I was unable to find anything remotely similar.
I have only elementary knowledge of insects. Any pointers in the right direction would be appreciated. Mealybug; don't know much about them.
The following is multiple choice question (with options) to answer.
Why would a plant not do well indoors? | [
"the temperature is not as good",
"it's not by other plants",
"the roots have less light energy to absorb",
"the chlorophyll has less light energy to absorb"
] | D | chlorophyll is used for absorbing light energy by plants |
OpenBookQA | OpenBookQA-727 | black-hole, gravity, supermassive-black-hole
For instance, as the Moon orbits the Earth, the Earth also orbits the Moon, they both orbit around a point between the two of them called the "Barycenter". This point is always closer to the more massive object.
In the case of the Earth-Moon system it's inside the Earth's volume. Therefore it's common believe that only the Moon's orbiting the Earth, without the other way around as well.
Topics you must check out besides the link provided in the previous answer:
The following is multiple choice question (with options) to answer.
The moon orbits an object that orbits the | [
"Earth",
"moon",
"sun",
"Mars"
] | C | the moon orbits the Earth |
OpenBookQA | OpenBookQA-728 | quantum-mechanics, water, liquid-state
Title: Quantum description of water It seems that we have quantum description of solid and gas, but there seem to be few quantum models of liquid, with the exception of Liquid Helium or perhaps Fermi Liquid.
For solids, we often study crystal, which is easier due to the lattice symmetry. For gas, particles often interact weakly so it's easy to formulate a non-interacting model. In this sense, I can see why people choose to study these systems first.
But are there any models that make use of quantum mechanics to explore the liquid phase? Perhaps a quantum mechanical description of water.
Maybe we can combine Shrodinger Equation and Navier Stokes equation in some way. Of course Navier Stokes equation itself is already hard enough, so perhaps we need to go to certain limits. Fermi liquid, Luttinger liquid, Bose-Einstein condensate, Superconductivity and similar states of matter are known as quantum fluids or quantum liquids, and there are books written on the subject, see, e.g., Interactions in quantum fluids. The word liquid/fluid is however somewhat ambiguous, as it may mean different (although not mutually exclusive) things:
The following is multiple choice question (with options) to answer.
Liquids | [
"can take on numerous formations",
"is always completely opaque",
"lacks any sort of malleability",
"is easily confused with the gas phase"
] | A | Matter in the liquid phase has variable shape |
OpenBookQA | OpenBookQA-729 | meteorology, climate-change, gas, pollution
Title: Regarding various types of atmospheric pollution Does all the car pollution (from about 150 million cars at least in the U.S. and a lot more in all of North America and the rest of the world) all the smoke-stack pollution of various factories and all the Airline pollution running day after day have a deleterious and damaging effect on the general atmosphere and, over time, the climate?
Given all the observed pollution that China has caused itself and some of the resulting weird weather events there this certainly seems to be evidence of the damaging effects of car and factory pollution. Has anyone calculated how much exhaust from cars is produced in one day on average in a 'moderate' sized city?
Of course it seems with all the increased oil production in the U.S. and elsewhere we, human beings are going to keep are love-affair with gas-powered cars for the next 200 or 300 years. That is if we don't use up all the oil and gas in the ground before then. As a USA resident, the EPA is the best place to start when wondering about the emissions inventory of atmospheric pollutants or pollutant precursors that affect the National Ambient Air Quality Standards (e.g. Particulate Matter, Carbon Monoxide, Sulfur Dioxide, Lead, Nitrogen Oxides, Volatile Organic Compounds). The EPA compiles a comprehensive emissions inventory of all criteria pollutants at the county level which is available in the National Emissions Inventory (compiled once every 3 years). You can see the summary of your county at http://www.epa.gov/air/emissions/where.htm. As for the effects of atmospheric pollution, it is important to consider the lifetime of said pollutants in the atmosphere in order to put their environmental impacts into perspective. For instance, the air pollutants covered by the National Ambient Air Quality Standards have immediate health effects when high concentrations are breathed in regularly. Both animals and plants are adversely affected by these irritating and sometimes toxic chemicals, but these pollutants are also reactive and do not last long in the atmosphere unless they are constantly being replenished (e.g. daily traffic). Air quality also impacts critical nitrogen loads on ecosystems and possible production of acid rain.
The following is multiple choice question (with options) to answer.
Which changes the environment? | [
"backyard vegetable garden",
"television signals",
"vacuuming carpet",
"taking a nap"
] | A | farming changes the environment |
OpenBookQA | OpenBookQA-730 | the-moon
Title: moonless night and lunar phase How to define moonless night? There is no moon at all during some night?
How to calculate and know whether the moon would appear during one night?
If the lunar phase is full moon, is it possible that the moon will not appear ? A moonless night is, as you suspect, a night in which the Moon does not appear visible in the sky. This happens once per month, when the Moon is near the Sun. Due to the proximity of the Moon and the Sun in the sky, at that time the Moon is the smallest sliver possible, and therefore not a full moon.
This is because it is actually the Sun that illuminates the Moon, and when the Sun and the Moon are in the same direction in the sky we are seeing the non-illuminated side of the Moon. Note the direction of the sunlight in this image:
Obviously, the direction of the sunlight is the direction of "up" during the day. If you look at the horizon slightly after sunset or slightly before sunrise, you might actually catch a glimpse of the sliver of Moon before it set or rises slightly after or before the Sun.
The following is multiple choice question (with options) to answer.
The moon is absent of | [
"craters",
"gravity",
"H2O",
"CO2"
] | C | the moon does not contain water |
OpenBookQA | OpenBookQA-731 | the-moon, earth, angular-diameter
I should mention that these calculations assume the the Earth and Moon are perfect spheres, separated by a constant distance. In reality, none of those things are true, so the true angular sizes of the Earth and Moon are a little different to what I've calculated above.
As ProfRob says, the Earth isn't a perfect sphere. It's slightly flattened at the poles, with a flattening factor of $f\approx 1/298.25642$. The Moon is also flattened, but much less than the Earth ($f\approx 1/830$), due to its much slower rate of axial rotation.
Also, the orbit of the Moon & Earth about their barycentre is moderately eccentric, with a mean value of $\varepsilon\approx 0.0549$, and the eccentricity changes depending on the distance to the Sun.
Here's a daily plot of the Earth-Moon distance for 2020, produced using Horizons.
The following is multiple choice question (with options) to answer.
How many revolutions does the moon make around the Earth during spring? | [
"one",
"six",
"three",
"twelve"
] | C | a revolution of the moon around the Earth takes 1 month |
OpenBookQA | OpenBookQA-732 | homework-and-exercises, newtonian-gravity, material-science, continuum-mechanics, estimation
Title: Can a building get taller at night? UberFacts recently tweeted "Office buildings are taller at night—a 1,300-foot-tall skyscraper shrinks about 1.5 millimeters under the weight of 50,000 occupants."
Is what they are saying valid? It seems unlikely, but 1.5 is relatively small compared to the actual height of the building. What is the most the building can shrink and under what circumstances? I don't think this sounds unreasonable as an estimate at all. Let's check it.
One designs a building as a compromise between two competing factors:
One needs all of the load bearing materials to be well mildly loaded - working in their linear region so that there is no danger of their undergoing plastic (irreversible) deformation, creeping then ultimately failing catastrophically;
However, mildly stressed load bearing members mean underutilized members: if we overdesign things too much we push the cost up enormously.
Let's for simplicity consider the compressive load bearing strength of the building against its own weight: it needs to bear shear stresses from wind as well, but considering the weight alone will get us to a ballpark figure.
Typical materials behave under stress in a way described by a curve with the following shape:
The following is multiple choice question (with options) to answer.
If a building suddenly collapses inward, the people working inside will likely | [
"go away",
"steer clear",
"depart earth",
"walk away"
] | C | buildings collapsing often cause death |
OpenBookQA | OpenBookQA-733 | sensation, olfaction
http://www.comeaddestrareuncane.com/blog/tag/cani-molecolari/
In the dog, the surface of the olfactory mucosa varies between 70 and 150 cm2 - in this tissue the number of olfactory receptors varies from 250 to 280 million - In 1962, Becker et al. showed that dogs are able to recognize substances in dilutions from 1/100 to 1/10.000.000.
- http://milano.corriere.it/milano/notizie/cronaca/12_febbraio_19/cani-olfatto-parere-esperto-1903358352720.shtml
Have you noticed how a dog sniffs the urine of a female "tasting it"? It is the same action that makes the viper when it follows the track of the mouse: it evertes the tongue and carries on it the odorous particles in the buccal cavity, and this organ has a function in the middle between the olfactory and gustatory ones. "Pointing dogs" is as pointing "the wild" taste the smell.
"Eat the scent", in the jargon, because savored, not only in terms of smell, the smell of the wild. The Jacobson's organ is then a second organ capable of perceiving odors, the first we've said is represented ciliated epithelium of the mucous membrane of the nose.
But there is a third organ called the "Rodolfo-Masera" which also serves to sense the emanations chemical (not yet known which), that way you could explain a specialization of these organs to perceive certain groups of biochemicals than others.
- http://www.laciotola.net/Cani/la-funzione-olfattiva-del-cane.html
The following is multiple choice question (with options) to answer.
What sense is associated with an animal's ingestion? | [
"taste",
"hearing",
"vision",
"touch"
] | A | when an animal eats or drinks something , that animal tastes that something |
OpenBookQA | OpenBookQA-734 | However, if said that an object is an apple if and only if it is a fruit ($\text{Fruit} \iff \text{Apple}$), then that would once again mean that something has to be a fruit in order for it to be an apple, but here the main difference is that it would also have to be an apple and not an orange or a banana. If it is a fruit, then it's an apple, and if it is an apple, then it is a fruit.
In the second example, we have also added $\text{Fruit} \Rightarrow \text{Apple}$ which, on it's own, means that if something is a fruit, then it has to be an apple. Another way of writing $A \iff B$ is $(A \Rightarrow B) \ \& \ (A\Leftarrow B)$.
## protected by Zev ChonolesJun 25 '15 at 6:00
Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
Would you like to answer one of these unanswered questions instead?
The following is multiple choice question (with options) to answer.
if a person eats a fruit, it is possible it was once which of these? | [
"none of these",
"it was a reproduction structure",
"it was a stone",
"it was a root"
] | B | some flowers become fruits |
OpenBookQA | OpenBookQA-735 | home-experiment, mixtures
Title: What household substances could be distilled I'm looking to experiment with distillation to have a basis for understanding the theory slightly better, and get a better feel for it.
I'm hoping for some suggestions as to what I could try distilling, such as purifying drinking alcohol. Any single idea would be appreciated, best answer would be awarded to an idea where:
The resulting purity would be straight forward to approximately test
No part of the distillation presents a significant hazard (e.g. toxic fumes, high volatility)
No particularly specialist or expensive equipment is required (e.g. extreme temperatures)
I think that pretty much covers it. I'm just looking for one or two ideas which I can experiment with besides alcohol.
Thanks This is tricky. Besides water, nearly everything has some hazard associated with it. And even water distillation involves high temperature (100C). Be careful distilling alcohol: the azeotrope of distilled alcohol is 95% ethanol which is VERY flammable! Plus, technically speaking, distilling alcohol may be illegal where you live.
One thing you could do is distill water with dissolved substances, most likely table salt (NaCl). This would help you test the principle that distillation is a technique for separating substances. In this case, distilling salt water should yield pure water. A more visual example would be brewed coffee or tea, which is a suspension and should separate into water and crud!
And after that, I'd be careful! For example, concentrating acetic acid (white vinegar) is dangerous, as concentrated acetic acid is both corrosive and has choking fumes. I would not even consider trying something that is not food grade, given your requirements.
The following is multiple choice question (with options) to answer.
Ethyl alcohol can be made by distilling and fermenting simple sugars from | [
"a starchy slurry",
"wet sand",
"dry sawdust",
"rice fields"
] | A | ethanol sometimes is made of corn |
OpenBookQA | OpenBookQA-736 | If the question is asking for the probability that either of the two cows is 2-coloured, we have
$$P(\text {1 cow is 2-coloured | both visible sides are black}) = \frac{P(\text {1 cow is 2-coloured and other is black}) \times P(\text {the black side of the 2-coloured cow is seen})}{P(\text{both visible sides are black})}=\frac{\frac{\binom{3}{0}\binom{1}{1}\binom{2}{1}\cdot\frac{1}{2}}{\binom{6}{2}}}{\frac{\binom{3}{0}\binom{1}{1}\binom{2}{1}\cdot\frac{1}{2}}{\binom{6}{2}}+\frac{\binom{3}{0}\binom{1}{0}\binom{2}{2}}{\binom{6}{2}}}=\frac{1}{2}$$
where $$\frac{1}{15}=\frac{\binom{3}{0}\binom{1}{1}\binom{2}{1}\cdot\frac{1}{2}}{\binom{6}{2}}$$ is the probability that the $2$ visible sides are black when one is 2-coloured and the other is black and $$\frac{1}{15}=\frac{\binom{3}{0}\binom{1}{0}\binom{2}{2}}{\binom{6}{2}}$$ is the probability that the $2$ visible sides are black when both cows are black (these exhaust all possibilities for both visible sides being black).
The following is multiple choice question (with options) to answer.
If a cow is offered a choice, it will turn down | [
"a bale of hay",
"a piece of carrot",
"a chunk of apple",
"a chunk of pork"
] | D | cows only eat plants |
OpenBookQA | OpenBookQA-737 | biochemistry, ecology, marine-biology, climate-change
So... raising temps can cause less mixing of water due to more stratification (layering), which results in less water in the ocean available to absorb and hold the CO2. This means that as atmospheric CO2 continues to increase, the non-mixing surface layer of ocean water (which will become saturated with CO2 at some point) won't be able to keep up with more and more and more CO2 in the air. As a result, the ocean will decline (and eventually potentially fail) in its ability to "buffer" the ever increasing CO2 in the air. This would mean that the rate of CO2 in the air will start increasing more rapidly (since less and less of it is being absorbed by the oceans).
As for the phytoplankton (which are in this top layer of water), this stratification will not directly result in less CO2 availability to them. As atmospheric CO2 increases, so will the amount in this top layer of water. The rate of increase in CO2 concentration will just slow until a saturation point is reached, but absolute levels will not decline.
Though, note, however, that phytoplankton tend to thrive in areas of high nutrients (i.e., upwelling zones). Less mixing of waters will decrease the upwelling of nutrient-rich, cooler subsurface water. So less mixing (i.e., more stratification) likely would lead to declines in phytoplankton abundance due to decreased nutrients availability. (See here). Perhaps this decreased nutrient availability (which would include loss of carbon sources) is related to what you're referring to?
Read here for some more thoughts: https://earthobservatory.nasa.gov/features/OceanCarbon
Raising Temperatures may decrease CO2 solubility
However, given all this, the solubility of CO2 in water does decline with increasing temperature (see here for raw data). This suggests that some rise in global temps may impact CO2 concentration in ocean waters.
The following is multiple choice question (with options) to answer.
When the availability of food sources increase in an environment, what will also increase? | [
"Trash",
"Bodies of Water",
"Animals/Plants",
"Air"
] | C | as the number of sources of food increase in an environment , the population of the organisms will increase in that environment |
OpenBookQA | OpenBookQA-738 | java, chess
// all possible moves in the up positive diagonal
for (int j = offSetCol - 1, i = offSetRow + 1; j > -1 && i <= board.length; j--, i++) {
String squareNote = String.valueOf((char) ('a' + j) + "" + (i));
Square square = getSquare(squareNote);
if (square.getSquarePiece() == null) {
;
} else if (square.getSquarePiece().getColor() == lastMovedColor
|| !square.getSquarePiece().getType().equals("B")
&& !square.getSquarePiece().getType().equals("Q")) {
break;
} else if (square.getSquarePiece().getColor() != lastMovedColor
&& (square.getSquarePiece().getType().equals("Q")
|| square.getSquarePiece().getType().equals("B"))) {
leftInCheck = true;
break;
}
}
The following is multiple choice question (with options) to answer.
I can use a Punnett Square to determine if | [
"I'll be able to walk on walls",
"If I will be invisible",
"I'll be able to have superpowers",
"I'll be able to twist my tongue"
] | D | a Punnett square is used to identify the percent chance of a trait being passed down from a parent to its offspring |
OpenBookQA | OpenBookQA-739 | python
def listen():
global loop_int, last_track
threading.Timer(loop_int, listen).start()
if it.player_state() == k.playing:
# check to see if track was restarted
if it.player_position() < getSec(it.current_track.time())/2 and last_track == it.current_track.persistent_ID():
self.last_track = '0'
# has the track played beyond the halfway mark?
if it.player_position() >= getSec(it.current_track.time())/2 and last_track != it.current_track.persistent_ID():
today = datetime.datetime.today()
now = '{}-{}-{} {}:{}:{}'.format(today.year, '%02d' % today.month, '%02d' % today.day, '%02d' % today.hour, '%02d' % today.minute, '%02d' % today.second)
print '\nArtist: {}\nTrack: {}\nAlbum: {}\nGenres: {}\nDatetime: {}'.format(it.current_track.artist().encode('ascii','ignore'), it.current_track.name().encode('ascii','ignore'), it.current_track.album().encode('ascii','ignore'), it.current_track.genre().encode('ascii','ignore'), now)
last_track = it.current_track.persistent_ID()
addTrack(it.current_track.persistent_ID(), it.current_track.name(), it.current_track.artist(), it.current_track.album(), it.current_track.genre(), it.current_track.played_count(), it.current_track.skipped_count(), it.current_track.year(), now, it.current_track.rating())
The following is multiple choice question (with options) to answer.
Playing music at a certain frequency may | [
"shatter a glass",
"send sound outside",
"hurt your teeth",
"crack a mirror"
] | A | vibrating matter can produce sound |
OpenBookQA | OpenBookQA-740 | pie. Let \$$\mathcal X\$$ be the \$$\mathbf{Cost}\$$-category where the objects are the elements of \$$\mathbb N[S]\$$ and \$$\mathcal X (x, x')\$$ is the time it takes to turn the list of ingredients described by \$$x\$$ into the list of ingredients described by \$$x'\$$ or \$$\infty\$$ if this is impossible. Some examples: $\mathcal{X}( [\textrm{flour}] + [\textrm{water}] + [\textrm{butter}], [\textrm{crust}]) = 30$ $\mathcal{X}( [2\textrm{flour}] +2 [\textrm{water}] + 2[\textrm{butter}] + [\textrm{filling}] , [\textrm{crust}] + [\textrm{pie}]) = 120$ $\mathcal{X}([\textrm{pie}], [\textrm{pie}]) = 0$ $\mathcal{X}([\textrm{water}], [\textrm{pie}]) = \infty$ Now suppose I am a busy person who prefers to buy my pie crust from the store instead of making it from scratch. Now the set of ingredients I need to make a pie is \$$T = \\{\textrm{crust}, \textrm{filling}, \textrm{pie}\\}\$$. I can create another \$$\mathbf{Cost}\$$-category \$$\mathcal{Y}\$$ where the objects are the elements of \$$\mathbb{N}[T]\$$ and \$$\mathcal{Y}(y, y')\$$ is again given by the time it takes to make transform the ingredients of \$$y\$$ into the ingredients of \$$y'\$$. Lastly we need to define a \$$\mathbf{Cost}\$$-functor \$$F:
The following is multiple choice question (with options) to answer.
When the pie came out of the oven is had more | [
"nutrients",
"calories",
"heat energy",
"apples"
] | C | if food is cooked then heat energy is added to that food |
OpenBookQA | OpenBookQA-741 | thermodynamics, temperature, everyday-life, phase-transition, humidity
Title: Steam from a cup of coffee I observed that, in winter there is more visible steam from a cup of coffee than in summer. Is there any phenomenon taking place here. The amount of water that air can take up before the water creates fog or visible steam depends on temperature. The colder the air, the less water it needs to create fog/steam. It is the same principle when hot air rises, for example when pushed up a mountain and then it starts to cool down drastically --> It will rain.
For more have a look at: Relative humidity in https://en.wikipedia.org/wiki/Humidity
The following is multiple choice question (with options) to answer.
Tiny particles of moisture may be found | [
"in what we all breathe",
"under the ocean waves",
"exclusively in hot steam",
"only in cumulus clouds"
] | A | water vapor is found in the atmosphere |
OpenBookQA | OpenBookQA-742 | botany, plant-anatomy
Title: Is it possible to grow any kind of plant soilless (hydroponics)? Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient solutions, in water, without soil. [wikipedia]
My question is if is it possible to grow any kind of plant soilless (hydroponics)? Yes, There are a few i know of, a quick "air plant" google search will get you quiet a lot.
wiki 1
wiki 2
Edit: I just glanced through the hydroponics article, and now I wonder if my answer actual answers your question.
The following is multiple choice question (with options) to answer.
What is a greenhouse? | [
"A place for foreign plants",
"A house painted green",
"A secret Army base",
"The opposite of the White House"
] | A | a greenhouse is used to protect plants by keeping them warm |
OpenBookQA | OpenBookQA-743 | meteorology, snow, radar
Also note that winter precipitation adds an extra complication because the particles are lighter in weight and can thus be blown about more by vertical and horizontal winds. Raindrops (and hail) are quite likely to fall unless extreme updrafts exist because they are heavy. But drizzle, snow, and sleet may be blown around quite a bit. Without a time-intensive dual-Doppler analysis, you cannot know the wind motion in the storm thoroughly, and therefore will have varying results at times.
And finally, the big wrench is unfortunate inherent to how radars work. They measure the percentage of their sent energy that is reflected back to them. That's great because that's directly connected to the diameter of the item falling (to the 6th power). But unfortunately the grand problem is that in a storm, there is a huge variety of drop/flake sizes mixed together at once... such that we can't extract which combination of particle sizes created it (and thus can't calculate volume to actually know the rain/snow amount that falls). It could be like 6 medium size flakes causing the 10 dBZ echo... or 2 large flakes and 10 small flakes... and each combination is a different volume/snow total. (to see the nitty-gritty math details on this, read more here.) So we can never know for sure the exact rain/snow falling using just radar. The good news is we've at least done lots of experiments and come up with some fairly useful best-practice formulas for using the Z-R ratio in different scenarios. Good, but not perfect.
The following is multiple choice question (with options) to answer.
Precipitation is when hail fall from clouds to the ground, and so is | [
"sprinkles",
"water",
"frost",
"clouds"
] | A | precipitation is when hail fall from clouds to the ground |
OpenBookQA | OpenBookQA-744 | gas-laws, heat
Title: How can I light a fire in this case? Is there any gas that contains oxygen so that it doesn't require oxygen from the environment in order to burn?
What I am trying to do is use LPG gas, which is fed through a pipe to a burner that is placed in an environment that has no air, somewhat like a vacuum. Is there any way to light the burner inside that vacuum environment?
A few wild ideas that I had included finding some gas that contains oxygen in itself. I may be wrong.
EDIT - The question doesn't end here. Please read the comments section below for any doubts that you might have. And if it isn't answered in comments section then ONLY comment. The most convenient solution for your question can be the Hydrooxy gas (also sometimes called the Brown’s gas). Simply put its water split into hydrogen and oxygen. Hydrogen and oxygen can be combined back by ignition and can create a maximum temperature up to 2800 °C (around 600–700 °C hotter than burning hydrogen in air), which makes it a good fuel for metal welding and cutting.
Though 2:1 hydrogen and oxygen ratio is enough to produce water via combustion, but on a practical solution you will need around 3:1 to 5:1 ratio to avoid oxidizing flames. The temperature you can achieve by burning hydrogen oxygen mix varies, depending on the ratio of both gases used.
Hydrogen and oxygen can be obtained via simple electrolysis.
$$\ce{2H2O + Energy -> 2H2 + O2}$$
and combined back as
$$\ce{2H2 + O2 -> 2H2O + Energy}$$
It might be worth noting that for all practical purposes, the energy you use to split hydrogen and oxygen will always be greater than what you can get by combining them back (like what happens in every combustion engine, humans have ever created).
If you are planning to develop an actual application, there are many precautions that you would need to consider, the most important of which would be back-fire protection (a common problem with gas based welding), so that the flame doesn’t reach back into the gas tank, which of course will explode.
The following is multiple choice question (with options) to answer.
The best way to start a fire is to use | [
"moisture deprived logs",
"old branches",
"green branches",
"chopped logs"
] | A | dry wood easily burns |
OpenBookQA | OpenBookQA-745 | 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.
When it's summer in the USA it's winter | [
"in the southern hemisphere",
"in the northern hemisphere",
"in the western hemisphere",
"in the eastern hemisphere"
] | A | June is during the winter in the southern hemisphere |
OpenBookQA | OpenBookQA-746 | atmosphere, ocean, hydrology, climate-change
Comment: I strongly endorse the use of wind and hydropower as sources of energy over the further use of fossil fuels. However, I still think it is important to do research into the actual renewability of presumed-renewable energy sources, as we don't want to end up with another fossil fuel-type situation, in which we become aware of dependency on these energy sources and their malignant environmental side-effects long after widespread enthusiastic adoption. Electricity from waves, from hydro (both run-of-river and storage) and from wind, are all indirect forms of solar power. Electricity from tides is different, and we can deal with that in a separate question. Global tidal electricity generation is not yet at the scale of gigawatts, so it's tiny for now.
Winds come about from the sun heating different parts of the planet at different rates, due to insolation angles, varying cloud cover, varying surface reflectivity, and varying specific heat of surface materials. Temperature differentials create wind currents.
Waves come about from wind, so they're a twice-indirect form of solar power.
Sunlight on water speeds up evaporation, lifting the water vapour into clouds, giving them lots of gravitational potential. That rain then falls, sometimes onto high land, from where it can be gathered into storage reservoirs that are tapped for electricity, or where it flows into rivers that are then harnessed in run-of-river hydro.
How much power is there? Well, the insolation from the sun is, at the outer boundary of the Earth's atmosphere, at an intensity of about 1400 Watts per square metre. The Earth's albedo is roughly about 30% - i.e. on average about 400 Watts are reflected back into space, giving an average irradiation into the Earth of about 1000 Watts per square metre. Picture the Earth's surface as seen from the Sun: wherever the Earth is in its orbit on its own axis, and around the Sun, the Sun sees a disc that has the Earth's diameter, so the surface area exposed to the Sun is just $\pi$ times the square of Earth's radius, which is about 6 300 kilometres.
So the incoming solar radiation is $1000 \times 6,300,000^2 \times \pi \approx 125 \times 10^{15} \rm \ W$
The following is multiple choice question (with options) to answer.
Wind is a resource that | [
"is a fresh idea",
"can be retrieved repeatedly",
"is a source of water",
"is useless in farming"
] | B | wind is a renewable resource |
OpenBookQA | OpenBookQA-747 | earthquakes, seismology, instrumentation, in-situ-measurements, diy
Title: Using accelerometer as a seismograph I'm using ADXL345 accelerometer with Raspberry Pi to build a seismograph. I've successfully hooked it up and can plot the accelerometer data in three axis. Is there any way to express these data in the form of the magnitude of an earthquake, of course, at the point of sensing? I know that it might be imprecise, but any representation would be helpful (e.g. Richter scale), and how to accomplish that. The magnitude of an earthquake is related to the total energy released, therefore to estimate it from a seismogram you need to know the distance to the source. In the case of the Richter scale for example, the relationship between magnitude and seismogram amplitude is defined for a standard distance.
If you have only one seismograph, you can not triangulate the location of the source (hypocenter). Therefore, you can not estimate the magnitude of a seismic event (Richter or moment magnitude).
But you can estimate the local seismic intensity of the event at the particular location of your instrument. With the accelerometer data you can easily measure the peak ground acceleration, that can be used to estimate the intensity in any of the existing scales. For example, the peak ground accelerations associated to each intensity level in the commonly used Mercalli intensity scale are:
Those g values would be easy to calculate with the accelerometer data and proper calibration constants.
Table taken from the Wikipedia page for peak ground acceleration
You might want to have a look at this question. There are some nice answers and references that you might find useful.
The following is multiple choice question (with options) to answer.
A seismometer can note how earthquakes are | [
"small",
"fast",
"strong",
"long"
] | C | a seismometer is used to measure the strength or magnitude of an earthquake |
OpenBookQA | OpenBookQA-748 | 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.
Which is most likely a pollinating animal? | [
"bear",
"spider",
"Anthophila",
"crocodile"
] | C | An insect is a pollinating animal |
OpenBookQA | OpenBookQA-749 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
What do herbivores eat | [
"stick bugs",
"radishes",
"leaf beetles",
"sea cucumbers"
] | B | herbivores only eat plants |
OpenBookQA | OpenBookQA-750 | desert
Title: When was the first not-icy desert formed? For how long have deserts existed and which one would be the first to be created? I'm talking about arid, dry deserts, not the Antarctic or Arctic or any other icy deserts. Deserts have existed since at least the Permian period (299-251 million years ago) when the world's continents had combined into the Pangaea supercontinent. Stretching from pole to pole, this land mass was large enough that portions of its interior received little or no precipitation, according the University of California Museum of Paleontology.
Pangaea broke into smaller land masses which were moved across the surface by tectonic forces, a process that both changed global climate patterns and the climate those continents were exposed to. As a result, current desert regimes date back to no more than 65.5 million years, according to this Encyclopedia Britannica article:
The desert environments of the present are, in geologic terms,
relatively recent in origin. They represent the most extreme result of
the progressive cooling and consequent aridification of global
climates during the Cenozoic Era (65.5 million years ago to the
present), which also led to the development of savannas and scrublands
in the less arid regions near the tropical and temperate margins of
the developing deserts. It has been suggested that many typical modern
desert plant families, particularly those with an Asian centre of
diversity such as the chenopod and tamarisk families, first appeared
in the Miocene (23 to 5.3 million years ago), evolving in the salty,
drying environment of the disappearing Tethys Sea along what is now
the Mediterranean–Central Asian axis.
Which would put the oldest of "modern" desert somewhere in the region of what later became North Africa or South Asia.
The following is multiple choice question (with options) to answer.
Deserts are generally | [
"sweltering",
"cold",
"tepid",
"frigid"
] | A | a desert environment is usually hot in temperature |
OpenBookQA | OpenBookQA-751 | mechanical-engineering, manufacturing-engineering, cnc
What minimum documentation of 'know how' should be provided for such a project, making complex mechanical parts out of aluminium?
Depends on what you mean by "minimum".
You could argue the drawing is the minimum...a bit lacking though if it doesn't have tolerances specfied and such. Just add process design experience.
Then there is the process manual which details the step-by-step the tooling and operation to be performed on the part, intermediary drawings, and tolerancing. Not cheap to develop, and also specific to the equipment you have available, but also not necessarily the only way to make to a part and not something you leave laying around. Used in industries like aerospace. I've been told each part actually has an its own copy of the manual following it around where the measurements after each process are filled in and signed off on.
The following is multiple choice question (with options) to answer.
A stage in the life cycle process includes what aspect? | [
"transporting water",
"reproducing ideas",
"entity replication",
"killing of kin"
] | C | reproduction is a stage in the life cycle process |
OpenBookQA | OpenBookQA-752 | botany, color
Hypothesis 1
It should be remembered that chlorophyll is far from being the only pigment found in leaves. For example, carotenoids - which give yellow and reddish colors - are present in plant leaves. There are many carotenoids (according to Wikipedia there are over 1100 known, but that number will continue to grow). The biological roles of these carotenoids are also varied. In the course of the question, we may be interested, for example, in the photoprotective role of carotenoids. They are involved in the deactivation of reactive oxygen species (ROS). ROS can be formed during photosynthesis and can potentially be harmful to cells. Therefore, in conditions of excess solar radiation, plants can increase concentrations of carotenoids to prevent oxidative stress. It has already been pointed out to you in the comments that younger leaves look yellow - this is a common occurrence. The leaf is a very expensive organ, in the sense that the plant invests a lot of plastic substances in its development. So it makes sense that young, growing leaves get extra protection. That is, a young leaf that has not yet formed all the necessary structures (thick enough cuticle, efficient conductive system, etc.) is less efficient in terms of photosynthesis and therefore more susceptible to negative processes of photodamage. Increased concentrations of carotenoids, among other things, can reduce such risks. If you add to this the small thickness, it is understandable why young leaves often look more yellow.
Hypothesis 2
I have already said that leaves are expensive organs. They have a high protein content, which is very valuable to the plant. If a leaf is damaged or aged, there is a threat of irreversible loss of protein, which would be a great waste. Therefore, in such cases, plants trigger complex processes of removing valuable substances from the leaves. In particular, chlorophyll begins to break down, and the decomposition products are transported to the more durable parts of the plant. This is the reason why leaves change color in the fall, before defoliation. When the concentration of chlorophyll decreases, other pigments, such as carotenoids, increasingly affect leaf color. That's why damaged and old leaves often turn yellowish.
Although, I doubt that in the case of your plant, this process is often the cause for yellow leaves.
Hypothesis 3
The following is multiple choice question (with options) to answer.
chlorophyll | [
"would avoid being pinched on St. Patrick's day",
"would blend in well in the arctic",
"is the color of an embarrassed person's cheeks",
"is a color used also to describe someone sad"
] | A | a chloroplast contains chlorophyll |
OpenBookQA | OpenBookQA-753 | physiology, ichthyology
Salmon use to deal with the NaCl fluxes driven by the gradients between the salmon and its surroundings. In their gill epithelial cells, salmon have a special enzyme that hydrolyzes ATP and uses the released energy to actively transport both Na+ and Cl- against their concentration gradients. In the ocean, these Na+-Cl- ATPase molecules 'pump' Na+ and Cl- out of the salmon's blood into the salt water flowing over the gills, thereby causing NaCl to be lost to the water and offsetting the continuous influx of NaCl. In fresh water, these same Na+-Cl- ATPase molecules 'pump' Na+ and Cl- out of the water flowing over the gills and into the salmon's blood, thereby offsetting the continuous diffusion-driven loss of NaCl that the salmon is subject to in fresh water habitats with their vanishingly low NaCl concentrations.
Reference
Reference
The following is multiple choice question (with options) to answer.
Gills allow | [
"flounder to intake oxygen",
"giraffes to breathe underwater",
"respiration for seals and herons",
"respiration for sea going birds"
] | A | gills are used for breathing water by aquatic animals |
OpenBookQA | OpenBookQA-754 | 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.
The purpose of bird feathers, especially down, is to | [
"retain body temps",
"contain moisture",
"move air around",
"help with flight"
] | A | down feathers are a thermal energy insulator |
OpenBookQA | OpenBookQA-755 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
How do Remora get their food? | [
"catch it",
"scavenge",
"hunt",
"steal"
] | B | remora fish eat food by attaching themselves to sharks and eating the food left behind |
OpenBookQA | OpenBookQA-756 | solar-system, history
Earth at the center.
Moon orbiting the Earth.
Mercury orbiting the Earth farther than the Moon.
Venus orbiting the Earth farther than Mercury.
Sun orbiting the Earth farther than Venus.
Mars orbiting the Earth farther than Sun.
Jupiter orbiting the Earth farther than Mars.
Saturn orbiting the Earth farther than Jupiter.
The celestial sphere of stars rotating around the Earth, being the outermost sphere.
The following is multiple choice question (with options) to answer.
The planet that contains many ecosystems is sequentially _________ from the center of its solar system | [
"fifth",
"first",
"third",
"fourth"
] | C | the Earth contains many ecosystems |
OpenBookQA | OpenBookQA-757 | population-genetics, conservation-biology
Where cloning can come in is it can be used to increase the gene pool, sometimes quite substantially. Consider the meta-population of a species, this could be allowed to include all of the wild sub-populations and all captive or managed (semi-captive) populations. For example, there are ~3900 wild tigers in the world, and ~5000 in captivity. Among all of those, only a subset contribute offspring to the next generation of wild animals, reducing the effective population size, and increase rates of inbreeding and genetic drift. For example, often very few males fertilise the females of a population with strong effects on the effective population size. What cloning could be used for (to various levels, depending on the specifics of the method) is to allow other individuals to contribute. For example, by cloning the members of a wild population that were unable to secure mates during a reproductive season (there is often high variance in mating success which reduces effective population), conservation managers can artificially re-inflate the effective population size to more closely resemble the census population size. In other cases, conservation managers may chose to clone particularly viable/fertile individuals that are approaching old age or nearing death, and are therefore at risk of being lost from the population. Conservation programs could use cloning of (semi-)captive individuals and introducing clones from (semi-)captive populations in to wild populations allowing genetic variation to be drawn from the gene pool of (semi-)captives in to the wild populations. Increasing the variance in the gene pool will increase the adaptive potential of the wild population. Another option is to clone wild animals in threatened areas (e.g. where populations are in decline as a result of poaching) and to put the clones in to safer areas such as national parks, or even zoos, to preserve genetic variation while conservation managers try to bring the other issues under control. Effectively this would act a bit like a seed bank.
The following is multiple choice question (with options) to answer.
To aid in increasing the population of an organism in an environment | [
"introduce more water sources",
"restrict the food supply",
"introduce more predators into the environment",
"create artificial drought conditions"
] | A | as the available water in an environment increases , the populations of organisms in that environment will increase |
OpenBookQA | OpenBookQA-758 | 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 balance can measure the weight of | [
"sugar",
"tea",
"salt water",
"chocolate milk"
] | A | a balance is used for measuring weight of a substance |
OpenBookQA | OpenBookQA-759 | acoustics, vacuum, frequency, resonance, vibrations
Title: Resonance and natural vibrations in vacuum In my Physics textbook, it says that if two pendulums of the same natural frequency are placed next to each other and if one is set into vibration, the other starts resonating and when the first one gets damped due to air friction, the vibration of the second one again sets the first into vibration (resonance) and this goes on until all the energy is dissipated as sound. My Question is: If placed in vacuum, will these two complement each others' vibrations and continue vibrating in perpetual motion (because there isn't any propagation of sound in vacuum due to absence of a medium)? No, because in a vacuum, there is no way for the two tuning forks (I think you meant this, rather than pendulums) to communicate. The reason a second tuning fork with the same resonance frequency will begin resonating is because, physically, sound waves are hitting it at its natural frequency. Sound waves travel in a medium, so in a vacuum, there's nothing to carry the sound waves and, hence, no communication between the tuning forks.
The following is multiple choice question (with options) to answer.
Which causes more matter vibration? | [
"megaphone",
"walking",
"speaking",
"yelling"
] | A | as the amount that matter vibrates increases , sound produced increases |
OpenBookQA | OpenBookQA-760 | newtonian-mechanics, newtonian-gravity, orbital-motion, planets
The Roche Limit can be viewed as an Earth shaped imaginary "border", on average 9,492 km from the centre of Earth, 1.49 times Earth's radius, for rigid bodies. So around the equator it "moves" outwards a little. It follows the oblate spheroid shape of Earth.
Earth may have had a ring just after its formation. The view of these ring from Earth would vary. It would all depend on your latitude and which direction you were facing. Near the equator, the ring would be like thin slices of light that erupted from distant Earth horizons and stretched into the sky as far as the eye could see.
Thanks to Emilio Pisanty for correctly pointing out the depiction of the rings from mid and high latitudes is not completely accurate. The plane of the ground is not orthogonal to the plane of the rings, so they would appear at an angle. All I can do is ask for some personal latitude in the presentation of this "what if" scenario.
The pictures assume the ring around Earth would be in the same proportion as the ring around Saturn is to that planet.
View of ring from the equator.
Why does the ring form around the equator as opposed to another axis.
It's due to the effect of the Central Force Law, the same basic reason the planets are situated in a plane around the Sun. The Sun is spherical,
so objects such as Pluto can "get away" with being 8 degrees out of line. If the Earth, and Saturn) were perfect spheres, then the axis of the ring could be at any angle. Because both planets are oblate spheroid, with a tidal bulge, over time the particles composing the ring would collect there. Saturn's rings have an estimated local thickness of as little as 10 metres and as much as 1 kilometer, so they are extemely "thin".
View of rings from the mid latitudes.
View of rings at 23° south latitude a 180° panorama gives an idea of what a magnificent sight the rings would be. The Earth itself is casting the shadow.
Image source: If Earth Had a Ring Like Saturn
The following is multiple choice question (with options) to answer.
the sun makes rounds around this planet | [
"maybe",
"this is wrong",
"all of these",
"this is true"
] | B | the Earth revolves around the sun |
OpenBookQA | OpenBookQA-761 | evolution, bioinformatics
Title: If we introduce any disease or deadly effect to a large group of living things, will such a group be able to develop a resistance? Like for instance, introducing cancer or radiation,
to a large group of insects/animals that can reproduce very quickly,
would it result in the surviving population of these living things to be more resistant to whatever adverse condition that was subjected upon it? Is there selection against cancer?
What is selection?
Let's start by explaining what selection is. Selection is a differential in fitness among different genotypes. In other words, if you consider a phenotypic trait for which there is some variance in the population. If, in the population, there is a correlation between this trait and fitness and there is a correlation between this trait and genetics, then there is selection.
The three ingredients for selection are
Variance for the phenotypic trait
Correlation between the phenotypic trait and fitness
Correlation between the phenotypic trait and genetics
These three bullet points are known as Lewontin's recipe. The last bullet point could be rephrased into "the phenotypic trait is heritable" and all bullet points put together could be rephrased into "fitness is heritable". Have a look at the post Why is a heritability coefficient not an index of how “genetic” something is? to understand the concept of heritability.
Is there selection on cancer?
Cancer is fundamentally a genetic disease. If this is unclear to you, you might want to read a bit more about cancer.
There is variance in the population in cancer (not everybody has a cancer but some people do) so we satisfied our first bullet point. Cancer is a genetic trait. So we satisfied our second bullet point. Cancer is a disease and therefore affect fitness (cancers kill) so we satisfied our third bullet point. In short, yes there is selection on cancer.
How does increasing the amount of carcinogens in our environment will affect selection on cancer?
From wiki
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis, the formation of cancer.
If you increase the amount of carcinogens in our environment, you are going to increase the prevalence of the disease, which will increase the variance for the disease (unless the prevalence would become very very very high) and therefore increase selection against cancer.
Does selection work?
The following is multiple choice question (with options) to answer.
Survival of an organism is positively impacted by | [
"access to food lacking in nutrients",
"access to dirty, tainted water",
"access to viable and required items",
"access to roadways and highways"
] | C | the ability to access resources has a positive impact on an organism 's survival |
OpenBookQA | OpenBookQA-762 | electromagnetism, maxwell-equations, magnetic-monopoles
&= \, g\,\, \frac{1}{r}\, \frac{d\vec{r}}{dt} \, -\, g\,\, \frac{1}{r^3}\,\left(\vec{r} \cdot \frac{d\vec{r}}{dt}\right) \vec{r}
\end{align*}
One can check directly, that the left-hand side can be rewritten as
$$\frac{d}{dt} \left(\vec{r} \times \frac{d\vec{r}}{dt}\right) = \frac{d\vec{r}}{dt} \times \frac{d\vec{r}}{dt} + \vec{r} \times \frac{d^2\vec{r}}{dt^2} = \vec{r} \times \frac{d^2\vec{r}}{dt^2}$$ and that the right-hand side can be rewritten as
\begin{align*}
\frac{d}{dt} \left(\,g\,\,\frac{\vec{r}}{r}\right) &= \frac{d}{dt} \left(\,g\, \,(\vec{r} \cdot \vec{r})^{-\frac{1}{2}} \, \vec{r}\,\right) = g\,\frac{d}{dt} \left( \,(\vec{r} \cdot \vec{r})^{-\frac{1}{2}} \, \right) \, \vec{r} \, + \, g\,\,\frac{1}{r} \, \frac{d\vec{r}}{dt}\\
The following is multiple choice question (with options) to answer.
what do the contents of electromagnets resemble? | [
"they look like shoes",
"they look like mice",
"all of these",
"the look like gas containers"
] | D | an electromagnet contains cylindrical ferrous metal |
OpenBookQA | OpenBookQA-763 | evolution, botany, proteins
tl;dr: the egg contains more proteins than the seed because the chicken that made the egg ate a whole lot of seeds, and all the protein in those seeds ended up concentrated in that one egg.
EDIT: running into this much later I realized I missed a pretty vital half of the question, because there is a difference between fruits and seeds. The difference is the following: nitrogen is precious for plants so they'll try and use it for very important things. Seeds are very important to the plant, so while a seed has less protein than an egg it will still have lots of protein by plant standards. Fruits now, that's another story. Like the sugary nectar, fruits are a bribe for animals, a bit of food offered to them so that they'll spread the plant's seeds. And like with the sugary nectar, the plant has every incentive to pack that bribe full of cheap carbohydrates and as few precious proteins as it can manage.
The following is multiple choice question (with options) to answer.
What does a seed contain stored food for? | [
"animals",
"people",
"cars",
"flora"
] | D | a seed is used for storing food for a new plant |
OpenBookQA | OpenBookQA-764 | earthquakes
Title: What is that spooky humming sound heard in earthquake footages? In most of the earthquake footages filmed outside during the earthquake that hit Mexico City on September 9, 2017 there was a distinctive streak of hum in rapid succession that could be heard in the background. It sounded like someone is constantly hitting the tuning forks onto a light tower like 2 times per second.
You can find numerous footages on youtube, but I picked one and fetched the audio portion covering the hums, you can listen to the audio at this link here (sorry I did not know how to upload an audio to SE).
Here is the waveform of the sound
What is that sound? What is causing this sound? If this was buildings or surrounding objects, why is there a pattern? Why is this sound heard in every footage no matter where they are filmed as long as they were filmed outside. Wailing sirens.
Examples 1, 2 where you see people come running out, i.e. exactly when you'd expect sirens, or 3, or 4 and 5 where they are explicitly mentioned.
The following is multiple choice question (with options) to answer.
Standing in a canyon and yelling your name | [
"will cause the canyon to shake",
"will cause your name to reverberate thru the canyon",
"will cause complete silence",
"will cause animals to run up to you"
] | B | echo is when sound reflects off of a surface |
OpenBookQA | OpenBookQA-765 | thermodynamics, energy-conservation, electrical-resistance, power
The thing is, when I then try some simple model like using specific
heat (I used the old thing from first year chemistry $Q = mc\Delta
> T$)I get rather large numbers for temperature increase, on the order
of thousands of degrees for a 120 V circuit.
The following is multiple choice question (with options) to answer.
Increasing the amount of heat can be done by | [
"adding gas to a fire",
"putting a pot on the stove",
"covering up with a blanket",
"moving to a warm climate"
] | A | an exothermic reaction increases the amount of heat |
OpenBookQA | OpenBookQA-766 | 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.
A locations climate is what in the area? | [
"Common forecast",
"water tide",
"rare storms",
"earthquakes"
] | A | climate is the usual kind of weather in a location |
OpenBookQA | OpenBookQA-767 | mechanical-engineering, structural-engineering, control-engineering
For example, if I wanted to setup such a facility, who would I have to consult?
You either find a consulting engineering firm with a lot of experience in designing and planning (and building!) such a plant. Or you find anexperienced hydroponics expert (the first bullet point) and a consulting firm with experience in a relevant field like wastewater.
Alternativly, you find a company specialized in building and selling hydroponics farms. This will give you less choice over the final plant - the company will want to work with their preferred components and concepts, and crucially they will want to reuse as much egnineering work from previous projects as they can.
The following is multiple choice question (with options) to answer.
Greenhouses work because | [
"windows allow in extra sunlight",
"carbon heats up inside",
"air retains humidity and warmth",
"gasses are trapped in buildings"
] | C | the greenhouse effect is when carbon in the air heats a planet 's atmosphere |
OpenBookQA | OpenBookQA-768 | thermodynamics, heat, microwaves
Title: Microwave oven heating time It's logical to think that the time it takes a microwave to heat the food would be proportional to the mass heated. But since a microwave is based on dielectric heating, I think that if you increase the mass of food there will be more water, which will heat the food faster (due to thermalization). Is this reasoning right?
Is there an optimal quantity of food to heat and the time it takes? Good question. The rate of temperature increase scales as the power absorbed by the food divided by mass of the food. So to understand your question, you need to understand how power is absorbed.
There is a finite amount of power in the microwaves being produced. These microwaves bounce around in the metal cage where you put your food, until they come into contact with the food. (Well, some of them will get absorbed in the metal by imperfect reflection, but let's ignore that at first.) Once they get absorbed by the food, they turn into heat. Because they bounce around until they hit some food, the efficiency of a microwave is pretty high, in the sense that most of the power generated in the form of microwaves goes into heating the food, regardless of how much food you have.
So, at lowest-order, increasing the mass will increase the amount of water, but won't increase the amount of power being absorbed by the food. But now, that thing about absorption by the metal comes in. The power absorption will be slightly greater with a lot of food, since the food will be more likely to absorb the microwave before it gets absorbed by the metal. This is a lower-order effect, but it's there.
Of course, then the issue of skin depth comes in. Microwaves only penetrate a certain distance into the food. (Of order an inch, depending on the food.) So increasing the mass isn't really what you want; you want to increase the mass that's within the skin depth. For example, a wide dish of water that's one inch deep will absorb better than a jug of water with the same volume. This is why you want to split apart chicken breasts when defrosting them, for example.
The following is multiple choice question (with options) to answer.
cooking a meal will lead to a transfer of energy into that meal? | [
"this is false",
"this is provable",
"maybe",
"all of these"
] | B | if food is cooked then heat energy is added to that food |
OpenBookQA | OpenBookQA-769 | rainfall, tropical-cyclone
Title: How can a storm drop 40 inches (1 metre) of rain? Hurricane Harvey dumped more that 20 inches (500 mm) of rain over a large region, with 40+ (>1000 mm) in some spots... and much more expected.
How is that possible?
Does the atmosphere really hold that much water?
Or is it getting repeatedly evaporated from the ocean and dropped onto the land by the circular winds, implying an enormous evaporation rate while over water? You were right to question whether the atmosphere really held that much water. It comes nowhere close! We use precipitable water to track this, which is the measure of all moisture in the entire column of air in the troposphere. We can get good widespread estimates from remote observations. This animation shows current amounts of precipitable water levels across the US from satellite. Here is a still from this afternoon (Sunday, August 27) during the Harvey event:
75 mm is less than 3 inches.
We also get in-situ exact measurements worldwide from twice daily radiosonde balloon launches. Unfortunately none are located right near the locations receiving excess rainfall. But you can check US sites of current precipitable water measurements any time by going to SPC's sounding page and looking for the PW value in the left side of the bottom table. SPC also maintains a climatology page for precipitable water and other values. You can see there that 3 inches (76 mm) of moisture in the sounding is extremely rare, and no US site has ever had 4 inches (102 mm) of precipitable water.
However, the answer is also not truly found in evaporation rates. The conditions in strong hurricanes do greatly enhance evaporation rates due to the high wind speeds and warmer waters. Measurements are actually a bit difficult to come by in such extreme conditions, with challenges in isolating evaporation effects from spray as well as in getting the instruments positioned into such environments (new field campaign: who wants to take the research ship out into the category 5 hurricane!?!). As this 2007 study by Trenberth et al. noted:
We are unaware of reliable estimates of evaporation in hurricanes, and published measurements do not exist in winds above about 20 m s−1 although some progress has been made in the Coupled Boundary Layer Air-Sea Transfer Experiment (CBLAST)
The following is multiple choice question (with options) to answer.
A storm moving over the earth will dump more rain on a | [
"arctic",
"desert",
"meadow",
"sandy area"
] | C | a grassland environment receives more rainfall than a desert |
OpenBookQA | OpenBookQA-770 | molecular-biology, neurotransmitter, muscles, receptor
Lastly, and on a slightly different subject, what are the microlesions in the muscles that occur during strength training, and what is the overcompensation that happens?
Last time I was updated on this (not my bag), there were some large questions remaining. The tricks used by growing muscle to establish large, regular arrays of contractile machinery, that is organized over many spatial orders of magnitude, are poorly understood. There are structures that monitor the overall organization and that detect any large deformations. Regarding overcompensation, let's play through a generic scenario. A muscle cell is loaded too much and becomes physically damaged. It has to stop taking orders (stop responding to contraction/relaxation signals) and to initiate repairs. The overcompensation results because muscle cell's not really capable of knowing how large it was before the damage, so the safe amount of repairs to do is extra. Probably there are epigenetic processes that let a muscle cell 'count' the number of times its been greatly damaged and to scale-up the response appropriately.
If you just consider two likely sources of damage -- mechanical strain and lactic acidosis -- you can see that there are widely different mechanisms that would be required to detect the damage and to initiate repairs.
The following is multiple choice question (with options) to answer.
After a long, hard workout, many professionals will help their body to heal by consuming | [
"electrolytes",
"protein",
"sugar",
"carbohydrates"
] | B | protein is used to repair cells by the human body |
OpenBookQA | OpenBookQA-771 | human-biology, eyes, vision, human-eye
Title: Superhuman eyesight My ten year old son was reading car number plates that were too fast, too far away and at the wrong angle for any of us to read or even believe that it was possible for him to read. We thought he was lying as he reeled off the whole number plate and not just some. My husband went across the road to prove him wrong and get him to admit he was making it up but he wasn't. We even asked people in the restaurant and waiting staff for their opinion and everyone was blown away. I'm totally astonished and slightly freaked out by his sight and I'm hoping someone can explain for me.
Specifics
The following is multiple choice question (with options) to answer.
can a kid with a new binoculars see a friend standing in a distance better or worse? | [
"visibility will be improved",
"visibility will be compromised",
"difference will be lacking",
"all of these"
] | A | binoculars are used for observing distant objects |
OpenBookQA | OpenBookQA-772 | astronomy, everyday-life, popular-science, climate-science
Title: Why is the summer, in the temperate latitudes, in average, hotter that the spring? It is common knowledge that the transition from the Spring to the Summer season occurs in the Summer Solstice when the "Sun reaches its highest excursion relative to the celestial equator on the celestial sphere" (as stated in Wikipedia).
It is also stated in Wikipedia' Summer page:
"Days continue to lengthen from equinox to solstice and summer days progressively shorten after the solstice, so meteorological summer encompasses the build-up to the longest day and a diminishing thereafter, with summer having many more hours of daylight than spring."
My question is: why is the summer, in the temperate latitudes, in average, hotter that the spring? A major part of the reason for this is due to the temperature of the ground. While the length of days in the Summer are effectively a mirror of those in Spring, you must take into consideration more than that.
When Spring commences in temperate climates, it is (usually) immediately preceded by winter. Due to the Winter, the ground and/or surrounding bodies of water are very cold. This has the effect of cooling the air for the first part of Spring while the ground/water begins to thaw/warm up. Furthermore, it takes much longer to warm or cool a body of water than a mass of air; even longer to warm or cool the ground and water. Therefore, as Spring progresses and the days become longer (also meaning the Sun is higher above the horizon, thus providing more heating power), the sunlight must first overcome the cooling effects of the ground and water bodies. Near the end of Spring - when the days are sufficiently long and the Sun is much higher above the horizon - you should notice the weather becoming hotter. This is because the ground and water has had time to warm up, which means it is not constantly cooling the air and making it feel colder.
When you then transition to Summer, the ground is already sufficiently warm but the days are still long and the Sun is still high in the sky. This means the Sun can heat the ground, water, and air even more and without any cooling effects. This allows the Summer temperature to be easily higher than that of the Spring temperatures. If Summer were immediately preceded by winter, you might notice the weather getting warmer much more quickly, but the average temperature would be very close to that of the Spring.
The following is multiple choice question (with options) to answer.
Summer is the season where | [
"solar flares are heating the earth",
"the hemispheres are rotating",
"a portion of the planet is in closer proximity to the sun",
"the sun is flaring up more"
] | C | summer is when a hemisphere is tilted towards the sun |
OpenBookQA | OpenBookQA-773 | evolution, zoology
Title: Why are hens so different from other birds? Hens lay many eggs during their lifetime (at least, I don't know of one which can lay more eggs) and they can't fly. Compared to other domestic animals it seems to me they are the least capable of defending themselves or escape if it comes to be left alone in open wild. What is their evolutionary story? Domestic organisms are bred to serve specific purposes for humans. Sheep are bred to produce wool; Cows are bred to provide meat and milk for human consumption; dogs are bred for service and companionship. Since domestic animal do need to survive in the wild in order to reproduce (ignoring feral animals, which is an interesting topic by itself), most of the other aspects of that animal relevant to its survival tend to be minimized.
So one could just as easily point out that there is no other animal that produces as much wool as a sheep, and yet producing copious amounts of wool isn't particularly useful to the animal itself (i.e. other than the fact that humans will tend to select good wool producers for breeding). So sheep are not particularly good at surviving in the wild, and yet they are incredibly successful as a species and are widely distributed, thanks to humans.
In short, domestic hens evolved to produce many eggs in their lifetime because over the past millennia since humans have started keeping them as livestock, humans tended to preferentially breed those individuals which produced more eggs and to eat those individuals which did not. Chickens tended to be kept in pens and guarded by humans or other animals, so the ability to defend themselves or flee from danger was not important to their survival, and in fact, those that did attack their handlers or escape were probably less likely to be bred.
This process is known as selective breeding or artificial selection.
The following is multiple choice question (with options) to answer.
After the chickens were let into the field, the population of worms | [
"decreased",
"increased",
"exploded",
"fluctuated"
] | A | if an organism dies then the population of that organism will decrease |
OpenBookQA | OpenBookQA-774 | 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.
A predator such as a wolf will show such a distinction by | [
"preferring rabbit to lettuce",
"turning down vegetables as food",
"chasing small moving mammals",
"eating meat when given it"
] | C | carnivores are predators |
OpenBookQA | OpenBookQA-775 | 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.
Over the years, the desert rat has evolved traits that help it live with low supplies of water, what is this an example of? | [
"Acquired statistics",
"Acquired interests",
"Acquired characteristics",
"Acquired heuristics"
] | C | an organism 's environment affects that organism 's acquired characteristics |
OpenBookQA | OpenBookQA-776 | evolution
There are other reasons why we do not regress to the mean as well, but I am writing a quick answer over breakfast, but I will be in the office soon where I can get some more thorough explanations from text books. E.g. (Dis)assortative mating, Mutation, Recombination, Environmental variance, Selection. However, with the increase in global movement it has become easier for dominant alleles to spread which is why the number of blue eyed people in the US is decreasing.
Here is an interesting article which backs up what I said about quantitative genetics, called "Will humans eventually all look like brazilians?" Also for good quantitative genetics texts take this as a basic intro and this for further reading.
The following is multiple choice question (with options) to answer.
Humans grow thinner when they | [
"lack food",
"eat too much.",
"overeat",
"eat food"
] | A | lack of food causes starvation |
OpenBookQA | OpenBookQA-777 | temperature, measurements, error-analysis
So, in summary: the absolute temperature of an everyday substance can be measured to 0.1 mK at the very best, in practice more like 1 mK with significant effort. The change in temperature can however be measured with microkelvin resolution, if sufficiently isolated from the outside environment.
The following is multiple choice question (with options) to answer.
Taking temperature is basically when | [
"looking outside at the weather",
"degrees of warmth are noted",
"measuring how humid the air is",
"how hot it is is discussed"
] | B | temperature is a measure of heat energy |
OpenBookQA | OpenBookQA-778 | electric-circuits, electricity, electrical-resistance
Charge conservation is always true.
Current conservation is true during steady state (which in usual electronics is always reached).
The following is multiple choice question (with options) to answer.
Conservation is | [
"using Styrofoam plates for every meal",
"reusing gift bags again and again",
"throwing plastic bottles in the landfill",
"driving a gas guzzling truck"
] | B | An example of conservation is avoiding waste |
OpenBookQA | OpenBookQA-779 | meteorology, geophysics, tropical-cyclone
Title: What is the largest hurricane possible? With Earth getting hotter and hurricanes also getting larger I wonder; Is there a limit on how big a hurricane can physically get? I am going to take an educated guess here because it is not possible(AFAIK) to accurately predict with any known skill what several decades into the future would be like.
Given that premise the largest hurricane in the future could be the size of the tropical extent of the Pacific Ocean or the Atlantic Ocean(wherever that begins and ends). Here I am only considering the Northern(or Southern) tropical extent of the Pacific or Atlantic Ocean because as we know a tropical cyclone cannot cross the equator as explained in this in depth answer Impossible or improbable? Hurricane crossing the equator. The thought process behind this idea is that hurricanes(tropical cyclones) dissipate on coming contact with land. Hence the maximum area of the largest cyclone in the future would have to be the ocean body maximum tropical extent(typically sea surface temperature (SST) greater than 27 degrees centigrade). Just in case if people are wondering why just the tropical extent and why not more than that ? It is because once you enter into mid latitude regions frontal processes could kick in(cold core cyclones-as an example -Can a tropical cyclone form in mid latitude oceanic waters?)
So if the tropical extent of the biggest oceans increases in the future one can imagine a very large possibly synoptic scale tropical cyclone.
Here I am excluding the North Indian Ocean basin because it does not have the surface area to compete with the North Pacific or North Atlantic
Secondly from this popular science article -How strong can a Hurricane get? and this one Are Category 6 Hurricanes coming soon ?
By the end of the 21st century, human-caused global warming will likely increase hurricane intensity, on average, by 2 to 11 percent, according to a review by NOAA's Geophysical Fluid Dynamics Laboratory, revised on Aug. 30, 2017.
followed by
The following is multiple choice question (with options) to answer.
The strength of a hurricane will increase | [
"in a sweltering environment",
"in a cold environment",
"in a breezy environment",
"in a dry environment"
] | A | as heat and moisture increases , the strength of a hurricane will increase |
OpenBookQA | OpenBookQA-780 | biochemistry, medicinal-chemistry
Title: What makes a metal safe to use for an artificial joint? What determines if a metal is suitable for transplantation such as in the hip? What I am most interested in however is why might some metals be toxic to animals once in the body? There are a number of reasons why a given metal may be toxic to an animal:
Radioactive metals are the easy ones.
Some metals can affect the normal biosynthetic pathways within the body. Lead is a good example of this, as it can take the place of calcium; I believe beryllium does the same for magnesium.
Some metals themselves are very reactive. Hexavalent chromium ($Cr(VI)$) is highly reactive, and will cause damage through severe oxidative reactions, whereas $Cr(III)$ is largely okay.
A lot of metals are okay, even required, at some level, but become toxic at too high a concentration. Iron, for example.
People can simply have allergies to metals. Nickel in silver jewelry is a good example, although in my experience it can be overcome.
The basic gist is that some metals are required for life, some aren't but aren't too terrible, and some are completely toxic to it. Different organisms can vary a bit in which metals are useful or not. A good implant will of course not be toxic at all, and will be strong and long-lasting. Titanium is often used, given its strength and general nonreactiveness, but so is cobalt, despite being toxic to some degree.
Ref: Metal Sensitivity in Patients with Orthopaedic Implants. Hallab, et al. J Bone Joint Surg Am, 2001 Mar 01;83(3):428-428
The following is multiple choice question (with options) to answer.
An animal needs what for for growing and repairing? | [
"calories from sustenance",
"warm water",
"reproduction actions",
"hunters ammo"
] | A | an animal requires nutrients to grow and heal |
OpenBookQA | OpenBookQA-781 | earth-rotation
Title: Which are the equations needed to calculate how much moving Earth's water with dams would change Earth's rotation speed? According to this article Drops of Jupiter
Raising 39 trillion kilograms of water 175 meters above sea level will
increase the Earth’s moment of inertia, and thus slow its rotation.
However, the impact will be extremely small. NASA scientists
calculated the shift of such a mass will increase the length of day by
only 0.06 microseconds
The following is multiple choice question (with options) to answer.
What quickly changes the Earth's surface? | [
"a hurricane",
"an earthquake",
"a flood",
"a tornado"
] | B | an earthquake changes Earth 's surface quickly |
OpenBookQA | OpenBookQA-782 | species-identification, zoology, marine-biology, invertebrates
Title: Help with jellyfish species identification Our research group (Evolutionary Genetics Group, University of Zurich) has received a letter from a special needs child who has kindly asked us to identify three jellyfish species.
Unfortunately, the letter does not include anything else except three rather low quality cutouts from what I assume is a childrens book. Nobody in our lab has any knowledge about jellyfish taxonomy so any help is greatly appreciated. Be warned that these are just best guesses - as you said yourself, these aren't great images for identification as they appear to be simple drawings:
1) this looks a lot like Aurelia aurita - though the lack of any internal patterning in the drawing makes me think perhaps otherwise.
image source: https://www.leisurepro.com/blog/wp-content/uploads/2017/05/shutterstock_272438348.jpg, https://holidays-majorca.co.uk/wp-content/uploads/2017/01/Aurelia-Aurita-S-300x225.jpg
2) possibly a Turritopsis dohrnii or nutricala - if so then this is the 'immortal' jellyfish. shape of bell is correct and the lappets seem reasonably close, it's just the internal structures that I'm not sure about.
image source: https://www.cairnsholidayspecialists.com.au/shared_resources/media/irukandji-jellyfish-in-far-north-18836_400x322.jpg
3) Very unsure about this one, but potentially a Atolla wyvillei? definitely has some visual features in common and I can't find anything else that's similar. I can also see how an artist would derive that image from this species.
The following is multiple choice question (with options) to answer.
Sea anemones | [
"look like flora",
"look like cars",
"look like bats",
"look like dogs"
] | A | poisonous darts are used for defense by sea anemones |
OpenBookQA | OpenBookQA-783 | python, performance, image
This is just 16,777,328 bytes long (one-88th of the size).
Instead of iterating over a range, iterate directly over the colour cube.
getNeighbors and filledNeighbors are identical except for the test against the unfilled array. So these two functions can be combined into one function that takes the condition to test. (In fact we'll see later that we don't need filledNeighbors.)
Now that unfilled is a NumPy array, getNeighbours can be simplified:
# Offset of the 8 neighbours of a point.
DELTA_I = np.array([-1, -1, -1, 0, 0, 1, 1, 1])
DELTA_J = np.array([-1, 0, 1, -1, 1, -1, 0, 1])
def neighbors(point, unfilled):
"""Return arrays of coordinates of unfilled neighbors of point."""
i, j = point
ni = DELTA_I + i
nj = DELTA_J + j
mask = unfilled[ni, nj]
return ni[mask], nj[mask]
(Note that this only considers the 8 neighbors of the point, whereas the code in the post considers the point too.)
The code in the post recomputes the surrounding average for every point in the perimeter. But this involves a lot of wasted work, because for most pixels in the perimeter, the average does not change from one step to the next. Only the pixels that are neighbors of the pixel that was just placed need to change. So if we maintain a running average of the filled-in neighbours of every pixel in the image, we can avoid nearly all this work.
2. Revised code
This answer grew quite long, so there are a few other tricks in the revised code that are not mentioned above. See if you can spot them and figure out how they work.
import numpy as np
import scipy.misc
The following is multiple choice question (with options) to answer.
When a new suburb was built there was less room for what? | [
"Tadpoles",
"Crime",
"Guns",
"Air"
] | A | if a habitat can no longer support animals then those animals will move to another area |
OpenBookQA | OpenBookQA-784 | geology, mineralogy
Title: Online resources for geographical distribution of minerals I'm trying to find the geographical distribution and availability of mineral Brannerite. Is there a resource online to know or query where a certain mineral is found?
On the link page, they mention certain types of geophysical deposits where this mineral is usually found:
"In granite pegmatites and in granitic gneisses; in silicified pebble conglomerates; in hydrothermal quartz and calcite veins; detrital in placers"
If the answer to the former question is negative; Would there be online information about geographical distribution of these geological features? You did not mention why you are interested in brannerite, so I am assuming you want it as a collector's specimen and not a microscopic crystal.
Unfortunately, there is no definite source. However, there are some possibilities:
Try the Handbook of Mineralogy: http://handbookofmineralogy.org and more specifically the brannerite page. You will fine there a more detailed list of localities for that mineral.
Another option is to run a Google Scholar search for brannerite. You can find scholarly papers dealing with brannerite, and occasionally they also mention where they found the mineral or how they obtained it. Notice that in the specific case of brannerite, there are many articles dealing with brannerite structure. This may not be what you're looking for. There is also the problem of accessibility - unless you have an institutional or personal subscription to these journals, you may not be able to access the full article. However, sometimes this information can be found in the freely available abstract.
Go to Rocks & Minerals magazine and run a search there for brannerite. They may have some articles dealing with localities.
The following is multiple choice question (with options) to answer.
if a person wanted some mineral graphite, where might they likely find some? | [
"in the potato bread for breakfast",
"in a pencil for drawing class",
"in the vanilla ice cream",
"in the flower of a plant"
] | B | pencil lead contains mineral graphite |
OpenBookQA | OpenBookQA-785 | waves, acoustics, atmospheric-science, weather
Even with the question of attenuation - when visibility is reduced to 40 ft, echolocation will probably beat it handsomely at intermediate distances. There are a couple of other interesting things you can do to improve your ability to see in fog.
1) Yellow "driving glasses". These work because they cut out the blue components of light. When fog droplets are very small, light scattering is in the Rayleigh regime - that is, scatter probability goes as the inverse fourth power of the wavelength, and blue (400 nm) light is 16x more scattered than red (800 nm) [note - using round numbers...]. By cutting out the blue component, you reduce the amount of scatter that reaches the eye and improve the contrast. Skiers also use yellow "fog glasses".
2) Scanning light source. This is one of those magical things that ought not to work but does. With normal (flood) illumination, light scatters "from everywhere to everywhere". If instead you look along the line of (say) a laser shining into the fog, then the only scattered light you see is the light that scatters exactly 180 degrees back at you - which is a small fraction of all the scattered light. If you scan the light source and detection system in sync, and very quickly, you can build up an "almost scatter free" image. This raster scanning technology is used in some underwater search applications and can penetrate about 6 "attenuation lengths". As was discussed in the comments, this method actually works best when the viewing angle is not exactly 180 degrees - not only is the back scatter from the fog weaker (there is a curious doubling of scatter intensity that happens at exactly 180) but also, by looking at a slight angle, you are able to eliminate the back scatter from the closest fog - greatly improving penetration.
More recently researchers in Israel have come up with a way to image through thin layers of scattering material - as you can see in the link, they are also able to see "through fog" (although it was not clear to me whether their technique can apply to actual imaging in fog).
The following is multiple choice question (with options) to answer.
which of these would help a person walk through a dark basement? | [
"a dead military torchlight",
"a blown out electric lamp",
"an oil lantern without oil",
"a candle and a matchstick"
] | D | a candle is a source of light when it is burned |
OpenBookQA | OpenBookQA-786 | gene-expression
Title: How does a gene "know" what to change to? Excuse my ignorance but I've always been curious about this...
For example, a frog is red, but it starts living in a green forest. Over time the frog becomes green to camouflage. But a gene can't see and I'm sure there's no mechanism for color info to be transmitted to individual genes from the brain. So how does a gene know to pick green over, say, blue? Using your example, the gene doesn't know anything. Mutations cause some of the offspring of the red frog to turn green, some to turn blue, some to turn fluorescent yellow, and some stay red. Birds can't see the green ones as well as the others, so more green frogs survive and make more green frogs. The red frogs, the fluorescent yellow ones, the blue ones, mostly get eaten. After a few generations, almost all the frogs are green -- not because the gene knew anything, not because the mutations went in any direction, but because all the other changes were counterproductive and got eaten.
The gene doesn't know anything. It's just a bunch of chemicals that randomly react with cosmic rays, chance, whatever. Most of the changes are irrelevant or actively bad, and the frog that's carrying those particular chemicals doesn't survive. But sometimes the change benefits the frog carrying the particular chemicals and then the frog sends those chemicals down to its progeny.
Obviously this is hugely over-simplified. A short and simple intro to the basics of evolution is Understanding Evolution, by UC Berkeley.
The following is multiple choice question (with options) to answer.
Genes are a vehicle that can pass | [
"hairstyle",
"hand size",
"nail polish",
"vocabulary"
] | B | genes are a vehicle for passing inherited characteristics from parent to offspring |
OpenBookQA | OpenBookQA-787 | botany, mathematical-models, statistics, biostatistics, migration
Title: Biostatistics: Pollen dispersal directionality What Information am I looking for?
Think about a tree that is sending pollen all over the place. Because of wind, most pollen grain will go toward one direction. Imagine, we split the 2D area around the tree where pollen grains fall into two half disks of equal size. We chose the disks so that the number of pollen grains falling into one half-disk is minimized and the quantity of pollen falling in the other half-disk is maximized.
The information I need is what proportion of pollen grain falls into each disk? Is it $\frac{0.5}{0.5}$ (in which case the wind would have no effect) or is it something like $\frac{0.8}{0.2}$?
Where to get the information from?
I was reading this paper about pollen dispersal directionality and was trying to extract the info I need.
On pages 4 and 5 they explain their analysis under the section statistical procedure. More specifically, in the first paragraph of the 5th page, they seem to describe the meaning of the parameters that are trying to estimate. One of them is the so-called directionality parameter $\delta$. I don't understand how to interpret this parameter $\delta$. This parameter is part of a logistic regression I think (although the authors do not characterize it as such) of "mating success" $y$ against variables $d$ ("distance") and $h$ ("height") and an angular variable $a = \cos(\alpha_0 - \alpha)$. ($\alpha_0$ is the "presumed prevailing direction of effective pollen dispersal," which apparently is not estimated from these data.) The corresponding parameters of the model are $\beta$, $\gamma$, and $\delta$, respectively, hence
$$\phi_j = \Pr(y_j = 1) = \frac{\exp\left(\beta d_j + \gamma h_j + \delta a_j\right)}{\sum_{k=1}^r \exp\left(\beta d_k + \gamma h_k + \delta a_k\right)}$$
The following is multiple choice question (with options) to answer.
The dispersal of what has a positive impact on plants? | [
"leaves",
"bark",
"branches",
"kernels"
] | D | seed dispersal has a positive impact on a plant |
OpenBookQA | OpenBookQA-788 | thermodynamics, physical-chemistry, chemical-potential, combustion
Title: How to thermodynamically understand process of burning a piece of coal? Let's imagine that I have a match in hand and nugget of coal on my desk. Then I light up the match and place it for few seconds near the coal so a tiny piece of nugget catches fire.
Then another piece catches fire, then another and soon all the nugget is burnt down.
How did it happen? I gave the nugget just enough heat to burn the first piece. Where does come energy to burn the rest of nugget from? It is called combustion, and it happens in materials which have a lower energy content when their component molecules join with the oxygen in the atmosphere, than when in a solid/liquid structure. When energy is given to start the fire the piece of coal burns and releases energy with excess enough to sustain the reaction and leave heat energy for use.
Combustion is a high-temperature exothermic chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke.
The following is multiple choice question (with options) to answer.
Being a nonrenewable resource means coal | [
"is highly sought after as an alternate energy source",
"can be replaced and replenished with enough time",
"the industry one day will cease to exist",
"is flourishing with an unending supply"
] | C | coal is a nonrenewable resource |
OpenBookQA | OpenBookQA-789 | electrostatics, electric-fields, electric-current, potential
Title: Sustaining a current in conductor placed in external electric field Consider the following arrangement-
We have a conducting sphere and a positively charged infinite sheet on the left. The field creates induced charges and the net electric field inside the conductor is zero after a very short time. During this short time, there is a current in the conductor as electrons as dragged opposite to the external electric field.
My teacher says that if we want to sustain this brief current we should connect it with a conducting wire making a closed loop. The electrons will flow anticlockwise giving a steady current, which I think is wrong.
When we connect the conducting wire, the sphere and the wire become one complete metal and after a short time again, there will be induced charges in this big metal and electrostatic condition will be reached. The potential inside will be the same everywhere so how will the current flow in a closed loop? There is really not much to add to the comments. Why are the charges separated on the two sides of the sphere? because there is an electric field that pushes the negative charges to the left and the positive to the right, right? This field is produced by the charge on that infinite sheet. This field exists not only in the space occupied by the sphere but everywhere. If you have another piece of metal in this space you will see the same effect, negative charges pushed to the left hand side, the side nearest to the infinite sheet. So another piece of metal is also the wire. The same effect as in the sphere is in the wire, the external field keeps the charges separated. You also can think, in a more abstract way, in terms of potential. Why the charges on the sphere do not get together? Because there is no potential difference between the two sides. The field of the charges on the sphere and the field of the infinite sheet compensate so that the surface of the sphere is equipotential. Connecting two points having the same potential with a wire does not result in any current flow.
The following is multiple choice question (with options) to answer.
An electrical conductor is needed to | [
"plunge a butter knife thru bread",
"bake a red velvet cake",
"power a two wheel bicycle",
"run a swing set"
] | B | An electrical conductor is a vehicle for the flow of electricity |
OpenBookQA | OpenBookQA-790 | energy, temperature, collision
Title: Change of temperature/thermal energy in a collision between two objects in an ideal condition As far as I know thermal energy is a part of internal energy which includes kinetic energy of particles of a body with respect to its center of mass. And temperature is related to this thermal energy.
If two solid bodies(one at rest) of equal size collides in an ideal condition(no friction or dissipation of energy) such that two surfaces of two bodies which collide are exactly of same shape, then that collision should be elastic. Considering that the surfaces of collision are of similar shape and that is why the force is unformly distributed all over the surface which does not cause any change in internal microscopic motion of particles.
But what if the two objects are of different sizes as shown in the image(fig-02) below? If we consider that the smaller one is in motion and it collides with the larger one, will the force applied on the surface of larger one be uniform? Or will it be for some moment non uniform such that a small part of gets slighlty dispaced in the direction of force and causes internal particles in that portion to dissipate energy due to collision with the surrounding particles? If the later case occurs, will it change the temperature ot total thermal energy of the larger body?
I am refering to such a condition as if the collision is taking place in space where ther is no air resistance, no friction.... That is no means of energy loss.
If two solid bodies(one at rest) of equal size collides in an ideal
condition(no friction or dissipation of energy) such that two surfaces
of two bodies which collide are exactly of same shape, then that
collision should be elastic.
The following is multiple choice question (with options) to answer.
The instance of which of the following colliding and causing death is considered to happen? | [
"Trees",
"Buildings",
"Animals",
"Electronics"
] | B | buildings collapsing often cause death |
OpenBookQA | OpenBookQA-791 | geology, volcanology, mineralogy, minerals
Title: Where can obsidian be found? Where is obsidian found?
Is it typically found on the surface or underground?
If underground, how far under (meters or feet would be perfect)?
Also, is it found everywhere on Earth, or just in areas where volcanic activity is (or was recently) high? Obsidian is formed when a rhyolitic (or felsic) lava flows cool rapidly. This must mean that it's mostly available on the surface (and I think if you go near volcanos you can find pieces of Obsidian on the ground) because molten rock cools much faster above ground than it does below, allowing the melt to cool with small crystals (as opposed to intrusive rocks which have larger crystals). This means that Obsidian is an extrusive igneous rock.
I am betting that Obsidian is very common around most active volcanos around the world!
The following is multiple choice question (with options) to answer.
The molten rock under the surface is called magma and once is appears on what area is it called lava? | [
"geyser",
"volcano",
"below ground",
"above ground"
] | D | lava is found above the ground |
OpenBookQA | OpenBookQA-792 | Since we have $21$ terms taking $20$ possible values, there are some $0 \le i < j \le 20$ such that $S_i = S_j$. It follows that the total number of hours of study between days $i+1$ and $j$ (inclusive) is a multiple of $20$.
If it is not exactly equal to $20$ hours, then it must be at least $40$ hours. However, this is over a span of at most $20$ days. Dividing this into three periods of at most $7$ days (say the first week, second week, and third week), by averaging we find that she must have worked at least $14$ hours during one of the weeks, which is not allowed.
Thus she must actually have studied exactly $20$ hours between days $i+1$ and $j$.
• Yes, that's a little cleaner as route to Wiley's lemma.Thanks. – Joffan Jul 17 '16 at 23:05
• @Joffan, agreed. It's indeed cleaner to use 20 "holes" with 21 "pigeons" rather than separating $S_l=S_i+20$ as an individual case in my proof. Thank you, Shagnik. – Wiley Jul 18 '16 at 3:59
The proof consists of two parts.
• Part I: Prove that a period of $20$ days is enough such that there must exist some period of consecutive days during which totally $20$ hours are spent on studying.
• Part II: A counterexample which shows that $19$ days are not enough is presented.
Proof of Part I
The following is multiple choice question (with options) to answer.
Twenty four hours are | [
"some hours on clock",
"minutes in a day",
"passing by the side",
"segments of a cycle"
] | D | one day is equal to 24 hours |
OpenBookQA | OpenBookQA-793 | # Reset the equation counter
\documentclass{article}
\usepackage{amsmath, amsfonts, chngcntr}
\newcounter{problem}
\newcounter{solution}
\newcommand\Problem{%
\stepcounter{problem}%
\textbf{\theproblem.}~%
\setcounter{solution}{0}%
}
\newcommand\TheSolution{%
\textbf{Solution:}\\%
}
\newcommand\ASolution{%
\stepcounter{solution}%
\textbf{Solution \thesolution:}\\%
}
\parindent 0in
\parskip 1em
\begin{document}
\section{Kinematics}
\Problem A motorboat going going downstream overcame a raft at point $\emph{A}$; $\tau$ = 60 min later it turned back and after some time passed the raft at a distance $l$ = 6.0 km from the point $\emph{A}$. Find flow velocity assuming the duty of the engine to be constant.
\TheSolution Let u be the flow velocity and v be velocity of boat in still water,
$$\frac{l}{u}=\tau + \frac{(u+v)\tau-l}{v-u}$$
$$u=\frac{l}{2\tau}=\frac{6}{2\cdot1}=3 \ km/hr$$
\Problem A point traversed half the distance with a velocity $v_0$. The remaining part of the distance was covered with velocity $v_1$ for half the time, and with velocity $v_2$ for the other half of the time. Find the mean velocity of the point averaged over the whole time of motion.
\TheSolution $$v_{av} = \frac{2\cdot v_0\cdot\frac{v_1+v_2}{2}}{v_0 + \frac{v_1+v_2}{2}}$$
\end{document}
The following is multiple choice question (with options) to answer.
A person needs to find a way to shore while on a raft. Another person tells the first person which direction to go in order to safely reach land, so the person directing is | [
"navigating",
"negating",
"relying",
"destroying"
] | A | An example of navigation is directing a boat |
OpenBookQA | OpenBookQA-794 | zoology, ornithology, ethology, behaviour
Title: Crow branch pecking behaviour I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what I found different was the crows were violently pecking the branches nearby them. I have no memories coming to mind of seeing this behaviour beforehand. I speculate that this behaviour could be threat displays, but a quick search on Google did not reveal to me any authoritative studies on this phenomenon. I'd appreciate more information and sources.
This question has been added as a casual observation on iNaturalist. This is a good question. This type of behavior -- pecking at a branch, wiping the side of the beak on a branch, pulling off twigs and dropping them, or knocking off pieces of bark -- is quite common among many corvid species, particularly when they are interrupted by something or someone that they might consider a threat. This includes not only potential predators but also potentially hostile conspecifics.
It is typically considered to be a form of displacement behavior. The concept of displacement behavior, from classical ethology, posits that when an animal experiences two conflicting drives to do two different things, it doesn't know which to do and does a third thing instead to dissipate the drive or anxiety. For branch-pecking in crows, see E.g Kilham and Waltermire 1990 Ch. 12.
Referece: Kilham, L., & Waltermire, J. (1990). The American crow and the common raven. Texas A&M University Press.
The following is multiple choice question (with options) to answer.
An example of instinctive behavior is | [
"southern winter flight",
"foreging",
"climbing",
"relocation"
] | A | migration is an instinctive behavior |
OpenBookQA | OpenBookQA-795 | electricity
Title: Why does electricity want to flow into the earth? If I grab hold of a live wire, current will flow through me and into the earth.
If there is an electrical fault in my home, current will flow through the earth wire, out into a ground stake and into the earth.
If enough static electricity builds up in the clouds it will be discharged to the earth through a lightning strike.
What is so special about the earth? Why does current "want" to go there? user253751 said, "[electric current] only flows in loops."
That's true, but what that user didn't say is that the electrical grid is connected to Earth in many places. There is a loop from the transformer outside your house, through the "live" wire, through you, through the Earth, through a long metal stake driven in to the ground near the transformer, and back to the transformer.
The grid is grounded like that to prevent atmospheric phenomena (the same that cause lightning) from building up dangerous static charges on overhead wires.
The current to any small appliance in your home is supplied by two wires. One wire sometimes is known as "hot," and the other is known as "neutral." The neutral wire is connected to Earth. If you touch it, then you won't feel anything. The "hot" wire is the one you don't want to touch. The voltage on the hot wire relative to Earth can be anywhere from around 110 V to 240 V depending on where in the world you live.
The following is multiple choice question (with options) to answer.
Sending electricity through what causes electric current to flow through it? | [
"ground",
"water",
"air",
"copper"
] | D | sending electricity through a conductor causes electric current to flow through that conductor |
OpenBookQA | OpenBookQA-796 | infection, amphibians
Title: What is this toad suffering from? Myiasis or chytridiomycosis? I found this toad on Aug. 29th at this location: position on osm
I think it is a bufo bufo, approx. 10 cm long. The nostrils seemed to be completely filled with a grey matter and from the activity of the floor of the mouth it apparently tried to breathe againgst this obstruction. It probably had enough oxygen via its skin though.
I tried to remove the obstruction using a blade of grass but this seemed to produce some pain as the toad closed its eyes on contact, so I stopped. The skin looked fairly normal and the toad was able to walk away after a while.
I can think of two causes for this condition.
Batrachochytrium dendrobatidis infestation
Lucilia bufonivora larvae
I could not see properly, if there were any larvae or unhatched eggs inside the nostrils, but as the rest of the skin seemed unharmed I assume the latter.
Is my assumption valid or is there even a third possibility? It is a female Bufo Bufo and you are right, there are toad fly (Lucilia bufonivora) larvae/eggs inside her nostrills. These flies lay their eggs inside toads' nostrills (specifically on Bufo Bufos) and the larvae start eating them. Sadly this disease ends up by the death of toad. They slowly eat nostrills, then mouth, eyes, and all the head.
Here's a photo of a male bufo bufo, without a head. Someone found it walking around at this situation. https://i.stack.imgur.com/I6twl.jpg
The following is multiple choice question (with options) to answer.
When a frog is born, it has tiny gills so that it can breathe underwater, even though in adulthood it will | [
"relocate to land",
"find lungs useless",
"make lung soup",
"burn air"
] | A | amphibians undergo metamorphosis |
OpenBookQA | OpenBookQA-797 | 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 komodo dragon's body temperature would be highest if immersed in | [
"lava",
"apple juice",
"liquid nitrogen",
"water"
] | A | a reptile is cold-blooded |
OpenBookQA | OpenBookQA-798 | microscopy, histology, fluorescent-microscopy
If I need a fluorescent one, wondering if there is anything else needed, like special lighting or special materials for tagging the cells, which seems like it might require extra stuff like centrifuge and who knows what else.
Samples can sometimes have autofluorescence (e.g. the chitin that makes up the cuticle of insects is autofluorescent) but most samples are not. Almost always a fluorophore is used to stain the specimen for something. These can be cheap or very expensive, depending on what you want to stain. This really depends on your sample and how it is prepared. And know that most 'good' samples' are dehydrated or are treated by chemical fixation, which requires chemicals you cannot usually find at a local pharmacy. It depends on how ambitious you want to get as an amateur microscopist!
Also, you won't need a centrifuge.
For the histology slides, wondering generally what it takes to do that too, if I can get by with a regular microscope.
You can get by with a regular upright widefield microscope for sure. If you perform the sectioning well (making thin slices of your sample) then even basic microscopes will produce fascinating images, provided your lighting is good. It helps to have a condenser or a nice lamp and some thin and clean glass slides for well illuminated images.
Maybe fluorescent microscopy requires advanced biotechnology of some
sort, which is sort of what I'm wondering, what the basics are.
It requires a little bit more optical work. I would stay away from it unless you are serious, because it takes quite a bit more work and equipment to make it minimally workable. Normal microscopy is certainly a lifetime of fun if you have the desire to find interesting samples and work to make them good for imaging.
Addendum: the principle of fluorescence microscopy is quite simple but aligning everything is actually quite difficult if you are an amateur with no specialized tools. Here is the principle only, notice how the input and output must be aligned and the small objective lens has to transmit both excitation and reflected light:
The following is multiple choice question (with options) to answer.
I can use a microscope to | [
"Look at an elephant",
"Look at the sun shine",
"Watch a mouse eat food",
"see the pores in a plant"
] | D | magnifying makes seeing small things easier through using a microscope |
OpenBookQA | OpenBookQA-799 | combustion
Title: Would blowing someone else's candle out make mine shine brighter?
Is the claim in this sign correct? Would a candle shine slightly brighter with slightly more oxygen in the room?
And what do you mean "The candles aren't literal."? The claim is certainly true for candles in different rooms. Even in the same room, the effect of one candle on another in terms of oxygen consumption is with all likelihood completely negligible, and the candles could thus be treated as completely separate systems.
As to your question about how the candles are not literal: The sign is a metaphor for how sabotaging someone else does not make you absolutely better, only relatively, which is not the kind that matters (and makes the total situation worse, since you now have less total light / talent / whatever).
Note that if oxygen is a very limited resource, blowing out one candle would make the others burn longer. In much the same way the metaphor does not work in a competition over limited resources. But in the physical situation, infinite oxygen is usually a good approximation.
The following is multiple choice question (with options) to answer.
what does lighting it cause a candle? | [
"it stays same",
"none of these",
"it gets shorter",
"it gets taller"
] | C | lighting a candle causes that candle to burn |
OpenBookQA | OpenBookQA-800 | the-moon, the-sun, earth
That explains the circular movement of the stars, the Sun and the Moon.
This is true for all locations on the Earth, except for the equator:
Is the Earth spinning? That depends, you can always choose a frame of reference that suits you. However, only one of them are non-rotating, the Inertial frame. In all the others we have fictitious forces acting, like centrifugal or Coriolis forces.
We can test if the Earth rotates by watching a pendulum throughout a day. The pendulum would then seem to slowly rotate during this period of time, meaning some fictitious "force" is acting on it. That means that we are located in a rotating frame of reference, and thus the Earth rotates.
The following is multiple choice question (with options) to answer.
The earth revolves around | [
"a heat source",
"the Milky Way",
"a neighboring planet",
"the moon"
] | A | the Earth revolves around the sun |
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