source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-1201 | steel, alloys, metals
Title: Do "non-iron steels" exist? There are numerous steel alloys, containing mostly iron, carbon, and some other metals. Generally speaking, we can think of them as if they were some type of steel.
My question is: do "non-ferrous steels" exist? I am thinking of pure, non-iron metals, containing a little carbon, just as is added to iron to turn it into steel. Or asked another way, are there other metals besides iron that are doped with carbon in order to form an alloy like steel?
In general, how does the addition of carbon affect the properties of these metals? Iron and carbon have an interaction which make them different from most engineering alloys. This is to do with both the relative size of C and Fe atoms and their chemistry.
Carbon atoms are just the right size to insert themselves into the crystal lattice of iron, this strains the lattice enough that it is somewhat harder and stronger than pure iron. However the really important part is that the presence of carbon allows steel to be heat treated. Here it is heated above a critical temperature at which the crystal structure changes and if it is cooled rapidly the carbon content prevents it from returning to it's 'normal' structure at room temperature and instead forms a multi-phase structure which is highly stressed but chemically stable and as such is very hard with a high tensile strength. This can be further modified by controlled reheating to partially reverse this transformation and produce a material with controllable strength hardness and toughness.
Note that the above is a quick overview and there are whole books on the detailed behaviour of steels as the iron-carbon system can exist is several different states with different crystal structures and various micro-structural combinations of them.
This type of heat treatment is pretty much unique to steel and certainly very different from the way that most alloys behave and is a result of the specific interaction between iron and carbon and depends on the fact that iron can exist as both body centred and face centred cubic crystals.
It is also achieved by very low concentrations of carbon, usually less than 1.2% or so. In fact only about 0.7% carbon by mass is soluble in iron and any surplus will tend to form carbides or precipitate out as graphite (as in cast iron).
The following is multiple choice question (with options) to answer.
High carbon steel contains | [
"nickel",
"ammonia",
"Na",
"Fe"
] | D | ferrous metals contain iron |
OpenBookQA | OpenBookQA-1202 | That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The total that we have observed the opossums to eat is 5% x 150 + 10% x 120 + 20% x 120 = 43.5 plants.
They eat 5% large, which a corresponding fraction of 5% x 150 / (5% x 150 + 10% x 120 + 20% x 120) = 17%
They eat 10% low for 10% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 28%
They eat 20% hybrid for 20% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 55%.
Checking... yes the total is 100%.
What we see is that the opossums prefer hybrid by far.
Small blueberries are their second choice.
Last edited:
#### anemone
##### MHB POTW Director
Staff member
Hi anemone!
What do you mean by the symbol E?
Anyway, you've found that the opossums eat 45.8% large and 54.2% small for a total of 100%.
But... what happened to the hybrid blueberries?
By the symbol E, I meant the blueberries (all 3 types of them) that are eaten by opossums...
That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The following is multiple choice question (with options) to answer.
Berries | [
"should be ate when they are green",
"keep your brain clean",
"Are only available in Canada",
"Are all very poisonous"
] | B | a berry contains seeds |
OpenBookQA | OpenBookQA-1203 | thermodynamics, statistical-mechanics
Edit 2 I am adding a diagram of the setup. The point is that I start with the setup at 50 °C and 1 atm with water at the bottom and an ideal gas that does not dissolve in water at the top with the two separated by a partition. What will happen when I remove the partition. Will some of the water in liquid phase convert into vapor phase? If so, how does one figure out how much of the water will convert into vapor? Assume we know the mass of the water and that of the gas. As others have said, here's the difference:
Case I: At 50 C and 1 atm, in a system that contains only pure water, all the water will be in a liquid state. That's what phase diagram (a) would show you if the axes were numbered -- you're not on a coexistence line; rather, you're squarely within the liquid region.
Case II: At 50 C and 1 atm, in a system that contains water and air, some of the water will be in the gaseous state.
The natural question is then: Why?
The answer: There's no entropy of mixing in Case I, but there is in Case II.
Specifically: Water molecules will move between phases from regions where their chemical potential is higher, to where it's lower, until the chemical potential is uniform, at which point you've reached equilibrium (with respect to the water).
At 50 C & 1 atm, the chemical potential of pure water in the liquid state is lower than that of pure water in the gas state. Thus, in Case I, where we only have the possibility of pure liquid water and pure gaseous water, all the water will stay in the liquid state.
The following is multiple choice question (with options) to answer.
Which of the following would be part of the water cycle? | [
"Breaking ice up into pieces.",
"Filling a swimming pool",
"A lake forming a cloud",
"Irrigating a corn crop"
] | C | evaporation is a stage in the water cycle process |
OpenBookQA | OpenBookQA-1204 | zoology, ecology, diet, predation
Cheetahs have been reported to suffer from intraguild competition by lions Panthera leo, spotted hyenas Crocuta crocuta and occasionally leopards Panthera pardus. These larger predators represent a threat to the smaller-bodied cheetahs as they can affect their food intake by limiting access to high resource areas or kleptoparasitism (e.g. 10–12% of kills are kleptoparasitized in Serengeti National Park (SNP)), and reduce population sizes via increased cub mortality (e.g. 73% of cub mortality was due to predation in the SNP). In response, cheetahs often demonstrate avoidance behavior to minimize interactions with dominant carnivores , with spatial and temporal partitioning regarded as the principal behavioral mechanisms by which this is achieved. Accordingly, cheetahs have been described as a refugial species that seeks competition refuges within the landscape with low densities of lions and spotted hyenas.
Rostro-García S, Kamler JF, Hunter LT. To kill, stay or flee: the effects of lions and landscape factors on habitat and kill site selection of cheetahs in South Africa. PLoS One. 2015;10(2):e0117743. Published 2015 Feb 18. doi:10.1371/journal.pone.0117743
(removed the citations)
The definition of the terms used in the above citation:
Intraguild predation, or IGP, is the killing and sometimes eating of a potential competitor of a different species. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another. - Wikipedia
Kleptoparasitism, literally meaning parasitism by theft, is a form of resource acquisition where one animal takes resources from another. Although kleptoparasitism of food (i.e., kleptoparasitic foraging) is the best known example, the stolen resources may be food or another resource such as nesting materials. - Sciencedirect.com
The following is multiple choice question (with options) to answer.
What is animal competition? | [
"wolves and bears eating salmon",
"a shark and marlin swimming fast",
"gazelles and zebras living on the plains",
"an oxpecker helping a rhino"
] | A | if two animals eat the same prey then those animals compete for that pey |
OpenBookQA | OpenBookQA-1205 | 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.
do all insects have to undergo every stage of change before becoming full grown? | [
"all of these",
"insects are born live",
"pupa stage is sometimes skipped",
"pupa is a required stage"
] | C | incomplete metamorphosis is when an insect reaches the adult stage without being a pupa |
OpenBookQA | OpenBookQA-1206 | electric-circuits, potential, electrical-resistance, conductors
These analogies are not exact and are only intended to give you a better feel as to what is happening.
Hope this helps.
The following is multiple choice question (with options) to answer.
An example of a circuit would be | [
"Rock climbing",
"running a mile",
"dimming a bulb",
"swimming a lap"
] | C | when an electrical circuit is working properly , electrical current runs through the wires in that circuit |
OpenBookQA | OpenBookQA-1207 | forces, classical-mechanics, energy
Title: What's the work done in an object to change its direction? Say, for example an object is moving 2m/s right and some force makes it travel 2m/s left. What would be the work done on this object? It starts and ends with the same kinetic energy, but clearly something had to be done to it to make it start moving left. Let's assume the force acting to the left is constant.
For it to change the velocity from 2 m/s to the right to 2 m/s to the left the force must first decelerate the object to 0 m/s. That means the force did negative work on the object because the direction of the force is opposite to the movement of the object while it slows down. Net negative work decreases the kinetic energy of the object.
But since the force remains, it now accelerates the object from 0 m/s to 2 m/s to the left. Now the force is doing positive work since its direction is the same as the motion of the object. Net positive work increases the kinetic energy of the object.
The amount of negative work done by the force to decelerate the object to 0 m/s equals the amount of positive work done by the force to accelerate the object to 2 m/s, for a net work of zero. Per the work energy theorem the net work done on an object equals its change in kinetic energy. Since the net work is zero, the change in kinetic energy is zero.
Hope this helps.
The following is multiple choice question (with options) to answer.
What would be an example of a force acting on an object in the opposite direction that the object is moving, which would cause the object's speed to decrease in a forward motion? | [
"seven bees are flying north while a car is driving west",
"a car is driving west with a person pushing it west",
"a car is driving east but the sun is rising in the east",
"a car is driving north with strong winds blowing south"
] | D | a force acting on an object in the opposite direction that the object is moving can cause that object 's speed to decrease in a forward motion |
OpenBookQA | OpenBookQA-1208 | materials
Title: Making Lyophilized Cake Lookalike using household ingredients I'm working on a machine learning model to identify flaws in vaccines in lyophilized cake form. To train the model, I need a number of samples that look something like this:
I have vials, but I'm having trouble making a suitable cake – I need something that will stick to itself when dried...
What I've tried so far:
Salt dissolved in water/isopropyl alcohol
Baking soda dissolved in water/isopropyl alcohol
Both of these turned back into powder (instead of caking) when dry.
Next, I'm considering using powdered detergent, adding water, then letting it dry...
How would you recommend making this using common household ingredients? You may want to consider whey. Looks like Karen Smith, Dairy Processing Technologist at the Wisconsin Center for Dairy Research, already did some of the work for you. The result depends on the specific type of whey (a high score of 4 or 5 on the caking test means the material cakes readily, forming a gummy crust):
Whey – (Scored 2-5) – whey exhibited a wide range of caking scores. How the whey is processed has a very large effect on the tendency of the resulting powder to cake as evident in this result. Clearly, two of the samples had large amounts of amorphous lactose and without the presence of significant amounts of protein the samples readily caked.
The following is multiple choice question (with options) to answer.
When something is condensed | [
"it is made into a wetter form",
"it is a liquid lake",
"it becomes molten liquid",
"it is damp inside"
] | A | condensing causes a liquid to form |
OpenBookQA | OpenBookQA-1209 | fluid-dynamics, flow, porous-media
separating
$$ -\frac{\mu_n B_n}{\mu_g B_g} dp=\left[\frac{\mu_n B_n}{k A}q_{sc}+ \frac{c\beta}{\mu_g A^2}\rho_{g,sc} \mu_n B_n q_{sc}^2\right]dx$$
Integrating
$$ -\mu_n B_n \int_{p_1}^{p_2}\frac{1}{\mu_g B_g} dp=\left[\frac{\mu_n B_n}{k A}q_{sc}+ \frac{c\beta}{\mu_g A^2}\rho_{g,sc} \mu_n B_n q_{sc}^2\right]\int_{0}^{L}dx$$
The gas formation volume factor, $B_g$, is defined as
$$\tag{7} B_g=\frac{p_{sc}}{p}\frac{T}{T_{sc}}\frac{z}{z_{sc}}$$
Substituting Eq.7 into the integral on the left-hand-side (LHS) of Eq.6, we have
$$I=-\mu_n B_n \int_{p_1}^{p_2}\frac{1}{\mu_g B_g}dp=-\frac{\mu_n z_n}{p_n}\int_{p_1}^{p_2}\frac{p}{\mu z}dp \ \ (\text{assume} \ T_n=T)$$
Using the initial reservoir pressure, $p_i$, as the "normalizing" pressure, $p_n$, we have
The following is multiple choice question (with options) to answer.
The supply of natural gas | [
"is renewable thru more mining",
"depletes without replenishment with every use",
"comes from synthetic creation",
"should be used as much as possible"
] | B | natural gas is a nonrenewable resource |
OpenBookQA | OpenBookQA-1210 | zoology, species-identification, ornithology, behaviour
Title: What is this crow eating, and is it a common part of the corvid diet? Here's a picture (by Rob Curtis) of a crow carrying and eating the corpse of what looks a bit like a small hawk or falcon:
Other pictures clearly show the crow is eating the dead bird. This image shows the underside of the head and beak; this one shows its legs, which are grayish.
What bird is being eaten?
Is this bird a usual part of the corvid diet? Or did the crow just opportunistically scavenge a dead bird? Crows are omnivorous, and will eat almost anything they find or can kill.
In this case the prey looks like a Yellow-Shafted Flicker.
The following is multiple choice question (with options) to answer.
Which of these animals might eat a steak? | [
"Chicken",
"Lion",
"Cow",
"Buffalo"
] | B | carnivores only eat animals |
OpenBookQA | OpenBookQA-1211 | 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 good reason for humans to feel little fear for wild wolves is that | [
"wolves are human",
"wolves elude humanity",
"wolves eat corn",
"wolves are domesticated"
] | B | animals usually distance themselves from humans |
OpenBookQA | OpenBookQA-1212 | photosynthesis
Title: What vegetation would thrive in the Martian atmosphere? Most plants require carbon dioxide for their photosynthesis, which Mars has in overabundance.
Would atmosphere composition (let's ignore temperatures for the purpose of this question) of Mars allow vegetation to grow? This is not my field by a long shot, so take what I say with a grain of salt. However, this question is very hard to answer because whether or not a plant will grow depends on a great variety of factors. Even if we ignore the temperature as you say, there are other considerations. These include, but are not limited to:
Soil composition, I doubt that Martian soil can support earth vegetation even if its atmosphere could. Plants need various nutrients, and specific pH ranges among other things.
Atmospheric pressure, I am not at all sure that the Martian atmosphere (though it is, indeed rich in CO2) would be enough to drive an earth plant's photosynthesis. Bear in mind that the atmospheric pressure on Mars averages 600 pascals (0.087 psi), about 0.6% of Earth's mean sea level pressure (source). This makes it highly unlikely that unmodified earth plants would be able to thrive there.
Water water water...
Pollinating species. Many many plants depend on other species (e.g. bees or hummingbirds) for their propagation. These would be hard to find on Mars.
Sunlight I don't know if Mars receives enough sunlight at its distance from the sun to drive an unmodified plant's photosynthesis.
Now, that said, it should theoretically be possible to start with some extremophile archaea or bacteria that would over the course of many many many years (at least hundreds, thousands more probably) terraform Mars to make it suitable for human habitation. Specially engineered plants could play a role then but I find it very hard to believe that any existing, unmodified, multicellular plant life of earth origin could survive on Mars.
The following is multiple choice question (with options) to answer.
which of these places would most likely sustain a growing plant? | [
"the ceramic tile in a kitchen",
"a water body front",
"the top of a mountain",
"the bottom of a clay pit"
] | B | a riverbank is made of soil |
OpenBookQA | OpenBookQA-1213 | quantum-mechanics, operators, quantum-information, quantum-computer, linear-algebra
For a given $x\in\mathcal H$, the decomposition in (2) is given by $x = u + v$ where $u = P(x)$ and $v = x-P(x)$. Note that $U=Ran(P)$ and $V=Ker(P)$.
The following is multiple choice question (with options) to answer.
What is decomposed in decomposition? | [
"lifeless life forms",
"living creatures",
"metals",
"plastics"
] | A | decomposition is when a decomposer breaks down dead organisms |
OpenBookQA | OpenBookQA-1214 | 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 shape of a hummingbird's beak is an adaptation for | [
"getting to hard to reach wood",
"getting to hard to reach females",
"getting to hard to reach rocks",
"getting to hard to reach nutrients"
] | D | sharp beaks are a kind of adaptation for catching prey |
OpenBookQA | OpenBookQA-1215 | 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 eat other animals? | [
"herbivores",
"bacteria",
"flesh eaters",
"giraffes"
] | C | predators eat other animals |
OpenBookQA | OpenBookQA-1216 | zoology, microbiology, pathology
Title: Prevention of disease spreading in animal kingdom It's my first question on here, so I'm not sure If my question fits the theme. Please refer me to the appropriate one, If I have made a mistake.
So a question that I wanted to ask has to do with whether or not animals potentially try to avoid spreading diseases. So I was thinking... In an event that a really deadly disease emerges in a population, it would be really dangerous for animals that live in social groups, of any size really, not to have any instinctual behaviours that try and prevent the disease to spread. Animals that live in big heads, like wildebeests would just probably leave the diseased individuals behind, apes and monkey could potentially cast out individuals from the group, etc. Ants have separate sections in their tunnels that serve as graveyards, I presume for this exact purpose.
A lot of parasitic organisms have adaptations that specifically target animals with social behaviour, so why wouldn't animals adapt against that?
Something that also came to my mind is that this could possibly evolve not as a social behaviour of a group, but sometimes that individuals in a group would do, for example self isolation. However, I do not find this likely, I possibly requires higher cognitive understanding of disease spread.
Am I way of base here? If not, could you please provide some interesting examples you are familiar with.
The following is multiple choice question (with options) to answer.
A lot of animals would avoid | [
"piles of discarded diapers",
"freshly off the grill steak",
"flowers that have just bloomed",
"pools of clear, clean water"
] | A | most animals avoid bad odors |
OpenBookQA | OpenBookQA-1217 | metallurgy, nuclear-chemistry, geochemistry
Title: Why are rare earth metals and platinum group metals are often found clustered together in ores Rare earth and platinum group metals are often found clustered together in the earth's crust. Mining for platinum, for instance, also yields Rhodium and Ruthenium belonging to the same group. Likewise, rare earth elements such as Neodymium, Europium and Samarium also cooccur in the same ore, so much so, that they are difficult to chemically separate.
It could be reasoned that it's the result of nucleogenesis where elements are formed consecutively based on their atomic number. While it might explain the first row and the second row of each group, where each metal is only one atomic number apart, it doesn't explain why metals from both rows are found together which are much further apart.
Alternatively, the similar chemistry of each group could explain the clustering. The two groups are the only group with this property. It fails to explain, however, how these metals found each other in a molten soup of heterogeneous elements. There may be some geological factors in the clustering, but it's unclear.
Why are the two groups of elements found clustered together? The factors that generate mineral concentrations are complex and often only partly known
Introduction: geology is complicated
The one thing we can be very certain about is is that the distribution of minerals in the earth's crust has very little to do with the primordial origins of the component elements (that is where they came from in the early solar system and how they were originally generated). Most "heavy" elements are originally formed in the cores of supernovae and not in either the big bang or in normal stars.
The distribution of elements in the earth is mostly unrelated to the cosmic origins of elements because the earth's crust is not static but is frequently churned up by a variety of processes on a geological timescale. If we go back far enough in the history of the planet, everything was molten and this allowed some of the denser components to separate out before the surface cooled enough to be solid. The led to the core being mostly metallic (and consisting of mostly iron and nickel). Higher layers contain less dense minerals containing a lot of silicate minerals. At the top there is a thin layer, the crust, which is where we find useful minerals and it is even more concentrated in silicate minerals and even less dense.
The following is multiple choice question (with options) to answer.
You can find ferrous metals in | [
"Grass",
"Vehicle scraps",
"Wood",
"Glass"
] | B | ferrous metals contain iron |
OpenBookQA | OpenBookQA-1218 | cardiology, health
Title: What shows how healthy someone is by their heart rate? What shows how healthy someone is by their heart rate - how low it is at resting pulse or how low it is during exercise or how large the difference is between the resting rate and rate with load? Any ideas?
Clarification:
Essentially, how does the heart rate reflect healthiness and in which ways (is it the resting pulse, pulse during exercise, differences, etc.)
Thank you for your time and effort A healthy heart and cardiovascular system distributes oxygenated blood more efficiently than a less healthy one. Therefore, for a given level of exertion, a healthy heart will need to pump fewer times than a less healthy one to provide the same quantity of oxygenated blood to the rest of the body.
It's pretty much that simple.
However, the whole patient has to be considered. A low heart rate in and of itself doesn't mean someone is fit since there are many drugs and medical conditions that can create a low heart rate. Person A sitting in front of you appears fit and healthy, is on no relevant medications, and has a heart rate of 50? Fitness almost certainly explains it. Person B sitting in front of you is overweight, on several meds and not very fit? Fitness almost certainly doesn't explain it.
The following is multiple choice question (with options) to answer.
After exiting the gym, the man's heart rate was most likely? | [
"higher",
"lower",
"normal",
"fluctuating"
] | A | as energy required for an activity increases , pulse will increase |
OpenBookQA | OpenBookQA-1219 | everyday-life
Due to friction effects though, option c is still best. Pedaling hard will quickly deplete energy reserves while pedaling at a slow but steady rate will allow you to cycle for much longer. From a physics point of view, we cannot help you spend less energy, it will inevitable take about the same amount of energy regardless of your method (some +/- due to friction, etc). But by keeping your power usage low, you can go much farther before needing a rest. It is much the same as with running and walking. Simplistic physics says both use the same amount of energy, but you won't get as far by running due to the massive power requirements.
The following is multiple choice question (with options) to answer.
Peddling a bicycle can be accomplished by | [
"dolphins",
"dogs",
"possessors of thumbs",
"emus"
] | C | a human can pedal a bicycle |
OpenBookQA | OpenBookQA-1220 | waves, electromagnetic-radiation, acoustics, interference, noise
It's two different things that are kind of analogous. I can't say it's impossible but it looks difficult.
The following is multiple choice question (with options) to answer.
if two things seemingly come closer together without a person interfering, which of these is likely? | [
"the objects are possessed",
"the objects could have magnetic properties",
"the sun is rising",
"all of these"
] | B | magnetic attraction pulls two objects together |
OpenBookQA | OpenBookQA-1221 | It just turns out nicely for C that he is one of the people whose hat colors D and C both know about.
To introduce a modified challange: if the task were to yell out C's hat color right away, D would know for certain, C would have the increased probability of $2/3$ and A and B would be stuck with the random guess of $1/2$. D still knows more.
The following is multiple choice question (with options) to answer.
If a bird is green, another bird can realize that by | [
"noticing it",
"visiting it",
"touching it",
"killing it"
] | A | the color of an object can be discovered by looking at that object |
OpenBookQA | OpenBookQA-1222 | fft, filters, audio
Here is some reading for you - I hope it will guide you and you will find appropriate method for your kind of signals.
The following is multiple choice question (with options) to answer.
Sound can be used for communication by | [
"creatures",
"plants",
"water",
"planets"
] | A | sound can be used for communication by animals |
OpenBookQA | OpenBookQA-1223 | marine-biology, molluscs
Title: Age of shells on beach As a child I watched tiny fiddler crabs living in conical shells, and many years later I find that people study fossil turritellids. So now I wonder: how old are shells, typically, that you see on beaches? Do they wear out after a year of sand abrasion? 100 years, a million? Is it known? Mollusk shells found on typical east coast (US) beaches can range from days old (the animal that made the shell died recently) to thousands of years old. Some shells in our state, North Carolina, have been dated as 40,000 years old. A high number of "seashells" found on east coast beaches are from mollusks that lived in the marsh on the back side of the island. The presence of these shells on ocean beaches provides evidence of island migration - the island has moved landward over the marsh until what was once the marsh is now the ocean shore. Once buried in the sand, the shell is well preserved until erosion uncovers it. Occasionally, fossilized shells are washed up on beaches after having been dislodged from offshore limestone deposits - these shells can be millions of years old.
-Richard -
Carolina Ocean Studies
The following is multiple choice question (with options) to answer.
A woman visits the same beach year after year, and begins to notice a change to a large wall of stone. Where the water touches the rock, she notices that the rock shows signs of being dissolved. After two year, there is an indent in the rock. After fifty years, the woman discovers that the rock | [
"is now an underground chamber",
"is now solid gold",
"is now about to explode",
"is now much bigger"
] | A | a cavern is formed by carbonic acid in groundwater seeping through rock and dissolving limestone |
OpenBookQA | OpenBookQA-1224 | fusion, renewable-energy
An energy "breakthrough" would be a loaded development. We already use lots of energy, and if we found it economic to use more we probably would. The last breakthrough shift in our ability to exploit energy resources rocketed the entire planet into a new geological era, the Anthropocene. We called this change the industrial revolution. Some obscure project that ARPA-E funded with $500,000 could cause the next industrial revolution. The implications of such a change would probably be beyond any of our imaginations.
The following is multiple choice question (with options) to answer.
In a year there is a complete revolution around a | [
"core",
"planet",
"star",
"moon"
] | C | a complete revolution of the Earth around the sun takes one solar year |
OpenBookQA | OpenBookQA-1225 | atmospheric-chemistry
But some researchers have argued it does make a notable contribution in the lower atmosphere, but indirectly. There doesn't appear to be a consensus on how big this effect is (and the Wikipedia reference is old and obsolete). The argument for ozone being a notable contributor is based on the following. Hydrocarbon pollution in the lower atmosphere (often from vehicle emissions) leads to a variety of undesirable reactions some of which lead to the production of ozone (as well as many other irritating components of smog). We really don't want too much smog or ozone in the lower atmosphere because it is bad for health. Some have estimated that it also adds to the warming caused by hydrocarbon emissions (exacerbating the warming potential of methane, for example).
It is hard to judge the estimates of its contribution to warming not least because they rely on models of complex reactions caused indirectly by other pollutants. Also, the big issue with emissions leading to ozone are not its contribution to warming but its contribution to pollution which causes direct harm to people in the short term. In fact regulations around emissions has been striving to reduce those emissions since before we started worrying about global warming. And, many countries have sharply reduced them (this is a major reasons why most western countries insist on catalytic converters in their vehicles). We should reduce ozone pollution by reducing the other emissions that cause it and we have been doing that for decades.
I would argue that ozone is essentially irrelevant to global warming. We should strive to reduce it in the lower atmosphere even if we were not worried by global warming. So even if we can't agree on how big its contribution to warming is (which the literature isn't clear on) we should be reducing it as much as we can for more direct reasons.
And, even if we wanted to report its contribution to warming, the best place to account for it is to add it to the contribution of other emissions (eg methane) rather than to account for it separately as we don't directly emit it from anything.
The following is multiple choice question (with options) to answer.
Which action may be seen an action that benefits the environment | [
"redeeming aluminum cans",
"burning trash",
"hunting deer",
"Building inground pool"
] | A | recycling has a positive impact on the environment |
OpenBookQA | OpenBookQA-1226 | proteins, food, digestive-system, amino-acids, digestion
Title: How are proteins reused in the body? Part of what we eat are proteins,
and our body is in part build of proteins.
Are the proteins of the body build based on proteins in food at all?
Are proteins in food directly reused in the body,
or are proteins first disassembled?
How far are they disassembled, randomly in various pieces, or systematically to keep what can optimally be used to build new proteins, while nothing is wasted for energy?
(The question Can proteins/peptides pass through the intestine? and it's answers are related, and provide some context and relevant parts, but is not a duplicate.) Short answer: Indeed the proteins in our body are based on amino acids from external food sources. BUT, proteins up-taken from food are ALWAYS disassembled first into amino acids, through specialized enzymes, proteases, (for instance Pepsin in the stomach's gastric juices and Tripsin in the pancreatic juices), during digestion, in the alimentary canal, (gut). This enables the body's liver to build the proteins most needed by the organism itself, through the processes of transamination, that allows conversion betwixt amino acids, and deamination, that removes N2 from the amino acid, (let's say the "amino" part is removed, and then expelled as urea), to excrete amino acids in excess. In addition this breaking down of external proteins is necessary, since they can act as labels for pathogens, and external organisms in general, and thus would soon be destroyed by the immune system if reused straight away.
The following is multiple choice question (with options) to answer.
What does the digestive system break down into simple substances? | [
"metals",
"stones",
"plastic food",
"nutriment"
] | D | the breaking down of food into simple substances occurs in the digestive system |
OpenBookQA | OpenBookQA-1227 | general-relativity, spacetime, curvature, tidal-effect
The "therefore" is incorrect.
In the language of Newtonian gravity, tides happen because of a differential gravitational pull between different places on Earth and its center of mass acting as a forcing term for the system of all the bodies of water, whose response function is rather complex.
See this excellent SE answer or Theory of tides on Wikipedia.
The different response accounts for the fact that bodies of water move by much more compared to land.
The thing that differs between Newtonian gravity and general relativity is the way the forcing term is handled; in this low-velocity, low-density regime their predictions are almost identical, although the language is different.
In this regime, the Newtonian language is to consider any given particle (molecule of water, say) to have an acceleration due to gravity:
$$ \frac{\text{d}^2 x^i}{\text{d}t^2} = F^i_{\text{grav}} + F^i_{\text{other}}
$$
where the $F_{\text{other}}$ term accounts for all non-gravitational forces.
In the language of GR, the main equation is the geodesic one:
$$ \frac{\text{d}^2 x^\mu}{\text{d}s^2} + \Gamma^\mu_{\nu \rho} \frac{\text{d} x^\nu}{\text{d}s}
\frac{\text{d} x^\rho}{\text{d}s} = F^\mu_{\text{other}}
$$
which in this case reduces to
$$ \frac{\text{d}^2 x^i}{\text{d}t^2} \approx - \Gamma^i_{00} + F^i_{\text{other}}
$$
and in particular, again in this approximation, $- \Gamma^i_{00}$ is quite close to the Newtonian expression for the gravitational force $F^i_{\text{grav}}$.
The following is multiple choice question (with options) to answer.
Gravity effects water most when it is | [
"on a curved surface",
"full of marine life",
"flowing rapidly with waves",
"in the ocean or lake"
] | A | water flows down a slope |
OpenBookQA | OpenBookQA-1228 | automotive-engineering, car
Title: How do hybrid cars achieve greater fuel efficiency? In this question I’m comparing non-plug-in hybrid fuel/electric vehicles with fuel-only vehicles. Also, I’m not disputing that hybrid cars are more fuel efficient, I’m just trying to understand how.
If I remember two things from high school physics, it’s:
Creating energy from nothing is against the law.
Converting energy from kinetic to stored energy and back again is always less that 100% efficient - you end up with less kinetic energy than you put in, the rest being “lost” to the environment in the form of heat or whatever.
The following is multiple choice question (with options) to answer.
Newer hybrid cars will have what effect on the gas usage in the world over time? | [
"less",
"more",
"more electric",
"slower cars"
] | A | as mileage per galon of gasoline increases , the amount of gasoline used will decrease |
OpenBookQA | OpenBookQA-1229 | magnetic-fields, earth
Title: Would a compass on its side point at the ground? From a point just north of the equator, A straight line to the Magnetic North would be through the earth. If a compass was turned on it's side, would the north pointing arrow point toward the ground along that straight line? A compass is usually used to find the direction of the horizontal magnetic field of Earth at that point. The needle of a compass is very light and thus its efficiency decreases when the compass is not in the horizontal plane at that point (due to gravity).Therefore, where the compass would point will become unpredictable. But, yes, in ideal conditions, the compass would point along the straight line joining that point to the north pole.
The following is multiple choice question (with options) to answer.
A compass | [
"knows orientation",
"Tracks People",
"Cleans",
"Invented in 1905"
] | A | a compass is used to navigate oceans |
OpenBookQA | OpenBookQA-1230 | physical-chemistry, inorganic-chemistry, everyday-chemistry, thermodynamics
Title: Strange observation! Every one have observed that when we pour cool water into a transparent glass (or simply glass), some droplets accumulate on the outside part. Did the droplets come pass through the glass? If they didn't, why is there accumulation of water droplets outside the glass? This is happening because of moisture present in air.
When you'll pour the cold water in a glass, the outer surface will also show fall in its temperature.
As you know already know that the heat flows from one body to another body until the temperature of both becomes equal.
So in our case the outer surface of the glass will absorb heat from surrounding, thereby causing in condensation of water present in air as moisture.
Another thing, you might notice that when you take out the bottle of cold water from a refrigerator, it have no droplets present on its outer surface because air inside the refrigerator is dry. But after when you place the same bottle out for a few minutes, you will observe the droplets on the outer surface of bottle.
You can also try to perform your experiment again by pouring normal water (at room temperature) in a glass and then placing it in refrigerator and then take it out after 30-40 minutes. Observe that if there are droplets present on the glass just after you take it out.
See this.
The following is multiple choice question (with options) to answer.
A person is cooled by a liquid coming from the | [
"clothes",
"eyes",
"hair",
"skin"
] | D | when the body is hot , sweat is produced to cool the body |
OpenBookQA | OpenBookQA-1231 | fluid-mechanics, thermodynamics, heat-transfer
Water will only condense when moist air is cooled below its dew point. The amount of water the air can store is not important to us in this case; just when it is at the dew point.
This means that in order for this system to produce any water, the night temperature must be less than the noon dew point. The final temp will be the noon dew point because any warmer and water will not condense, it will evaporate. As such, if it continues past that point it will evaporate all the water it gained.
To calculate how much water will be produced you will use something like:
Rock_Specific_Heat * Rock Mass * ΔT(night_temp to noon_dewpoint) =
The following is multiple choice question (with options) to answer.
condensation is a stage in the water cycle process when | [
"ice splashes water in my glass",
"a raindrop lands in my eye",
"a moist film is on my spectacles",
"sweat falls into my eyes"
] | C | condensation is a stage in the water cycle process |
OpenBookQA | OpenBookQA-1232 | thermodynamics, perception
Title: Our Perception of Heat Our body temperature is roughly 37 degrees celsius (that is, when we measure our body temperature externally, by using a thermometer that measures the temperature of our skin usually between our arm and side torso), whereas most of us would say that 25 degrees would be a pretty hot day. Why do we perceive a 25 degree day to be hot, when thermal energy from our 37 degree bodies should be leaving out and entering our surroundings? You are correct in a sense of thermodynamics. The heat from a human body does indeed leave the body and into the surroundings. The body combats this by burning calories and producing more heat, keeping the internal body at a constant temperature.
I'm not a biologist however:
Perception of a hot day, is just because our nerves our telling our brain its a given temperature. We are warm blooded animals, our body naturally generates heat. Lets assume that the body generates the same amount of heat every day, our brain may interpret a 25C day as warm because the body is generating the same amount of heat however it is leaving the body into the surroundings at a slower rate.
Temperature sensing is a survival tool, it used as a way of keeping the body at a constant temperature. As it gets hotter, your brain is in a sense telling you that it's getting harder to cool. (Forgive my terminology)
Think of this, if the day was as hot as the human body, you would be at danger of heat stroke.
The following is multiple choice question (with options) to answer.
An animal usually requires a warm body temperature for survival, such as | [
"a bird in a tree",
"a snake in a desert",
"a fox in the snow",
"a shark in the water"
] | C | an animal usually requires a warm body temperature for survival |
OpenBookQA | OpenBookQA-1233 | geophysics, climate, rain, nitrogen
Title: Rain Water vs Sprinkler Irrigation During the rainy season, the crops like corn, cotton are found to be growing faster. Studies shows that the thermoelectric fixation of gaseous Nitrogen during rain storm accelerates the plants growth in rainy season.
Can this effect be seen in Sprinkler irrigation ?
Is it possible to mimic this effect in other irrigation methods? I think what you mean by thermo-electric nitrogen fixation is the nitric oxides created by lightning discharges. This is absorbed by the raindrops as they form and as they fall to earth, and helps to fertilise the soil. You won't get this effect with sprinkler irrigation to any great extent, because the water droplets are exposed to the nitrogen oxides for far less time. In addition, sprinkler use is not usually accompanied by lighting flashes, whereas rain sometimes is.
If your crops are watered mainly by sprinklers and you would like them to have more nitrogen, you should practice rotation of crops. Some years you plant legumes, which fix nitrogen by means of the nitrogen-fixing bacteria which live in the nodules in their roots. In the tropics, a kind of acacia called mimosa, though not related to legumes, has the same nitrogen-fixing capability. This acacia is sometimes called 'the sensitive plant', as when touched its leaves rapidly fold themselves away.
The following is multiple choice question (with options) to answer.
A rainy environment results in | [
"more overcast days",
"more sunny days",
"less overcast days",
"a dry environment"
] | A | as the amount of rain increases in an environment , available sunlight will decrease in that environment |
OpenBookQA | OpenBookQA-1234 | earth, rotation, temperature
Title: What contributes the most to the seasonal temperature variation? The seasonal temperature is ultimately due to the precession of the Earth around the axis. But what I'm curious about is... is it due more to the side experiencing winter being farther from the sun or is it more due to the fact that the days are shorter and the nights are longer? [ The earth is actually closer to the sun in the Northern hemisphere's winter. The seasonal temperature variation is predominantly due to the angle the earth makes with the sun. In the northern hemisphere in winter the angle is such that the earth is tilted with north pole away from the sun and the sunlight hitting the earth is spread over a much larger area than if it was pointed towards the sun. Due to this tilt the sun is also lower in the sky and has the effect shown in the 2nd figure.
The following is multiple choice question (with options) to answer.
Winter in the northern hemisphere is occurring on | [
"the day after July 4th",
"two days before April 23rd",
"the day after November 30th",
"the day before Halloween"
] | C | December is during the winter in the northern hemisphere |
OpenBookQA | OpenBookQA-1235 | food, decomposition
Title: Worm compost cannot have cooked food I live in the Netherlands and it is getting fashionable to compost with worms. After investigating a few websites I noticed that most websites suggested that I cannot feed the worms leftovers from citrus fruits. This seems logical. I then started noticing that people advise against feeding the worms cooked food.
I'm no biologist but I cannot imagine a reason why cooked food is bad for the worms. Could anybody explain why this might be in layman’s terms? There are a few reasons for not feeding cooked foods to worms (Eisenia spp.) in a smaller household size worm farm. It's not because the food is cooked but what it often contains.
The earthworm used in vermiculture is usually Eisenia fetida (red wigglers) though other Eisenia species are sometimes used. All Eisenia are epigeic species meaning they live in the junction of decomposing organic matter (such as leaf litter, aging manure, rotted fallen trees) and their natural food is decaying plant matter and bacteria that are also digesting the organic matter. They don't make use of small dead animals (meat and fat).
In large scale commercial vermiculture operations, leftover and past-due-date foods from restaurants, institutions, nursing homes and schools are used along with plant matter and carboard and paper. I'm not sure how they balance cooked foods but possibly much less is used than plant matter.
The fact food is cooked isn't the problem but what's in it and/or what happens to it when added to the bin. If you have leftover vegetables and fruit that's been cooked with no added salt, it's perfectly acceptable. A certain amount of sweetened cooked fruit is also fine as the worms will eat that too. But ready-made foods usually have preservatives, salt, fats and spices added. Either worms won't eat it, leading to odour caused by mouldy rotten food, or it can make them unthrifty and even killing off your worms if it's fed them repeatedly.
The following is multiple choice question (with options) to answer.
What kind of organisms decay? | [
"harvested turnips",
"alive humans",
"sleeping dogs",
"hibernating bears"
] | A | dead organisms decay |
OpenBookQA | OpenBookQA-1236 | evolution, mathematical-models, theoretical-biology, population-dynamics, population-genetics
Title: Effective population size when the population sizes varies from season to season Let's think of a species which has four generations per year and which population size changes from season to season so that the population size is 100 in summer, 200 in spring, 50 in autumn and 20 in winter for example. In such case, the effective population size $N_e$ can be calculated by:
$$N_e = \frac{n}{\sum_{i=1}^n\frac{1}{N_i}}$$
where $n$ is the number of generation per year (4 in my example) and each $N_i$ correspond to the population size in one season.
My question
Can you please provide an explanation of why this formula (based on the harmonic mean) holds true to define the effective population size?
The following is multiple choice question (with options) to answer.
What shows that as the size of a flower increases , the number of pollinators it will attract increases? | [
"butterflies blend in with flowers where they exist",
"ducks prefer to sleep in water that has flowering water lilies",
"people prefer to walk through gardens that have a large number of flowering plants",
"planting flowering plants causes bees to gather en masse"
] | D | as the size of a flower increases , the number of pollinators it will attract increases |
OpenBookQA | OpenBookQA-1237 | transform
Originally posted by rohan with karma: 358 on 2013-04-29
This answer was ACCEPTED on the original site
Post score: 2
Original comments
Comment by mharms on 2013-04-29:
Thank you very much, for your rapid help and the provided image. Yes, it is set to /map. I will try changing this tomorrow when I am back to my work.
The following is multiple choice question (with options) to answer.
Maps may be redrawn because of | [
"an avalanche",
"a deep freeze",
"a glacier",
"an earthquake"
] | D | an earthquake changes Earth 's surface quickly |
OpenBookQA | OpenBookQA-1238 | reaction-mechanism
It is generally said that reactants react so that they can achieve a
lower energy state. Then why does a reversible reaction occur in the
first place?
Good question. Remember that we can always add energy to make an unfavorable reaction proceed. For example, the sodium ion, which is isoelectronic with neon, is stable with a full octet of electrons. However, we can still take away more electrons. It just takes a rather sizable application of energy.
The following is multiple choice question (with options) to answer.
Chemical reactions can be the cause of new formations of which? | [
"Temperatures",
"Shapes",
"Colors",
"Substances"
] | D | chemical reactions cause different substances to form |
OpenBookQA | OpenBookQA-1239 | arachnology
Title: Did or do these gigantic spiders really exist in Finland and/or Northern Europe? In the year 2000, the newspapers in a small coastal town of Finland ("Hanko"; current population: ~8k) had some very disturbing reports of a couple who had just moved into a new rental apartment/house in the central part of the town, and there encountered these monstrous spiders that look like they come straight out of a horror movie. In fact, apparently, they are literally the kind of spiders used in the classic spider horror movie "Arachnophobia"...
Digging through old things recently, I encountered the saved newspaper pages and was shocked by just how large and disgusting they look. I must have repressed this whole thing for the last 21 years, since I first heard about it when it was current. From the oddly-worded Swedish-language report (clearly not written by somebody with perfect Swedish skills), it's not made clear whether the couple was "just" working on fixing the place up, or if they actually had already moved in and saw these monsters while they were there to sleep. But the basic point is that the spiders allegedly existed at all, and may well still exist...
The article also notes that these spiders were "common" in Denmark in the beginning of the 1900s, further creeping me out. My initial assumption and hope was that these spiders had miraculously survived in their undisturbed habitat for 50 years (the article also mentions that they were "last spotted" in the 1950s), and that they were not native to Europe at all, but simply had been accidentally shipped in a crate with exotic fruits or something from some tropical island somewhere back in the day, and had not spread but simply hung around in their little basement in a place which, somehow, just happened to not have any humans going there for all these years.
The article further mentions that some kind of professor had determined them to be Tegenari Atrica spiders. However, looking them up on Wikipedia, I got redirected to the disturbingly named article "giant house spider", where it's mentioned that these are:
among the largest spiders of Central and Northern Europe.
And:
original habitat consists mostly of caves, or dry forests where it is found under rocks, but it is a common spider in people's homes.
The following is multiple choice question (with options) to answer.
What is one use of a spider's web? | [
"camouflage",
"obtaining sustenance",
"home",
"decoration"
] | B | a spider web is used to capture food by spiders |
OpenBookQA | OpenBookQA-1240 | geology, geophysics, climate-change, carbon-cycle
We can see here in white numbers the most significant pre-industrial sources and sinks (at ~1000 years time scales). We can see that humans produce 9 Gigatons of carbon per year (GtC/yr), due to that extra inflow, photosynthesis is taking 3 GtC/yr more than before, and the ocean is taking an extra 2 GtC/yr as well. However, that is not enough to counteract the 9 GtC/yr we produce, and that is increasing the amount of carbon in the atmosphere at 4 GtC/yr. This means the level in the atmospheric "bath tub" is still rising.
If we were to keep those 9 GtC/yr we produce stable (i.e. not increasing production in the future). The concentration of $\ce{CO2}$ in the atmosphere will rise to a level high enough that the sinks will match the sources, for example with plants taking 5 GtC/yr and the ocean 4 GtC/yr, that would nicely balance the production. But that new equilibrium atmospheric $\ce{CO2}$ concentration would be high enough to rise Earth's temperature several degrees and force a whole reorganization of the Earth's climates.
Finally, we have to say that some of these $\ce{CO2}$ intakes, like the oceanic one, don't come for free, and have their own nasty consequences, like ocean acidification.
The following is multiple choice question (with options) to answer.
the earth is the source of | [
"joy",
"natural resources",
"humanity",
"intellegence"
] | B | nature is the source of natural resources |
OpenBookQA | OpenBookQA-1241 | equipment, history-of-chemistry
Title: Help me identify this glassware! I'm a freshly graduated physics and math teacher moved into a small school from the late 1920s. The equipment here is old and confusing, at the very least. I have found many things which I have never seen before. I would like some help identifying what I have and what I can do with them, if anything.
(Click the images to view them at full size.)
1. A load of copper pots. For boiling something perhaps?
2. Some sort of wash bottle? Why is the cork on there?
3. I managed to make out "unitized wash bottle" on the back. This serves the same function as the last one, I presume.
4. It reminds me of a graduated cylinder until the frosted top and the "arms" that poke out the sides. What is this for?
5. This reminds me of halogen bulbs. Again, I have no idea what this is for.
6. I've taken to calling this "trumpet" glass pipe. What is it used for?
7. This large bulb has confused me since day one. I feel like it needs some sort of current passed through the ends. It reminds me of a cathode ray tube in a way. I'm completely lost on this one.
8. Here. Have a free safety poster! Not as good as old Carol, though. #4 is a collection vessel of some sort.
The ground glass fitting would have connected to some other ground glass fitting. A set of the ears would be on the connecting piece of glassware also. Then springs would hold the two pieces together.
The following is multiple choice question (with options) to answer.
Which item can help someone who is trying to conserve? | [
"a plastic fork",
"a paper towel",
"a shipping box",
"a menstrual cup"
] | D | An example of conservation is avoiding waste |
OpenBookQA | OpenBookQA-1242 | the-moon, moon-phases
Title: Red cresent moon Yesterday night i witnessed something very strange when i looked outside the window. I saw the moon (crescent) but it was dull red and right on the horizon ,which is strange considering that it is usually on the upper right of the night sky and white in colour. On further inspection with my binoculars i noticed it was lowering down until it was hidden by the mountain range (5km away) next to my building, this all occurred within a few minutes (about 5).
Tonight i saw the moon (crescent) had again returned to its normal position.
Please explain the cause for this, i'm completely baffled!
(Sorry for the poor wording, i'm not familiar with all the astronomical terms!) The dull red color has been due to atmospheric causes, like the reddish sun close to sunset. There hasn't been an astronomical reason for the reddish color.
A few days after New Moon moonset occurs short after sunset, so you won't see the Moon high over the horizon at those evenings. With each day the Moon is a little higher above the horizon after sunset. It's hence less close to the horizon at the same time of the day. Less close to the horizon means less atomospheric absorption/scattering responsible for the dull red color, assuming the same weather conditions.
At Full Moon the Moon is at the opposite side of the Sun relative to Earth. Moon is then rising shortly after sunset.
The following is multiple choice question (with options) to answer.
The moon | [
"has seven great lakes",
"is devoid of seas",
"is larger than the Earth",
"has a powerful magnetic field"
] | B | the moon does not contain water |
OpenBookQA | OpenBookQA-1243 | thermodynamics, thermal-conduction, thermal-insulation
Compress the fleece thinner so there is less air volume. The acrylic will conduct better than the captured air.
Replace the air with a more conductive fluid like water, or oil, or thermal grease containing conductive metal powder.
Instead of using acrylic polymer for the fibers, fill or replace them with a more conductive material.
Design the material to have larger pockets that allows more internal convective currents.
Use black and darker colors as they have higher emissivity.
The following is multiple choice question (with options) to answer.
This material was less of a thermal conductor | [
"aluminum",
"copper",
"thermal underwear",
"steel"
] | C | metal is a thermal conductor |
OpenBookQA | OpenBookQA-1244 | newtonian-mechanics, forces, rotational-dynamics, friction, free-body-diagram
Title: How does friction stop a car? I'm unable to understand how friction causes motion in cars and also is responsible for stopping them.
When it starts the impending motion of tyres is in the backward direction that's why friction is in the forward direction and the car starts moving.
But when the car engine turns off, the car stops after some time, but the condition of tyres are the same as in the previous case and friction must be in the forward direction. It is not the same friction, but rather the friction between the wheels and the breaking pads (and in general between the rotating parts of the car and their supports.)
The following is multiple choice question (with options) to answer.
A vehicle stops when brakes are pressed because | [
"the tires are being halted by pressure",
"the streets are bumpy",
"the roads have friction",
"the tires are unable to create friction"
] | A | friction is used for stopping a vehicle by brakes |
OpenBookQA | OpenBookQA-1245 | human-biology, eyes, vision
When combined with our Rod sensitivity, though, Green wavelengths produce nearly double the sensitivity the Red Wavelengths - and nearly quadruple the Blue wavelengths. What that means is that in low-light situations when the Cones are unable to produce a precise color image, your Rods will be able to pick out Green things (with a slightly loose definition of 'Green') more than other colors - which is perhaps the reason why night-vision goggles often use Green since they increase the Intensity of the light, which presumably stimulates the Rods more (although not knowing precisely how the image is produced - if the green coloring is enhancing that particular bit of the spectrum of falsely colored - take this with a grain of salt).
Does that explicitly prove you can see more Green shades than others? No. Your brain does a lot of processing - the entire color Yellow is a construction of your brain, and Tetrachromats (people with 4 types of Cones) are real.
However, like I said above, I'd say it's plausible.
The following is multiple choice question (with options) to answer.
Which of these is usually green in color? | [
"The Alps",
"Antarctica",
"Redwood National Park",
"The Pacific"
] | C | a forest environment is often green in color |
OpenBookQA | OpenBookQA-1246 | earthquakes, seismology
Title: Do planetary alignments affect Earth's seismic activity? There is a widely circulated tweet by Frank Hoogerbeets where it seems he has predicted Turkey's earthquake a few days before. The tweet says:
Sooner or later there will be a ~M 7.5 #earthquake in this region (South-Central Turkey, Jordan, Syria, Lebanon). #deprem
I have searched a bit about the origin of this so-called prediction. They have a youtube channel since a few month ago, which is regularly updated by videos like this in which he analyzes the planetary alignments and claims that it has something to do with Earth's seismic activities. I haven't seen such claim anywhere before and wanted to check whether it has been scientifically approved, or does it have any merit whatsoever? It's easy to make prediction of earthquakes in Turkey/Türkiye, it's in one of the most active seismic zones on the planet.
The February 2023 earthquake had a magnitude of 7.8, with aftershocks of magnitude 7.5.
In 2020 there was a magnitude 7 quake, 6.9 in 2014, 7.2 in 2011, 7.2 and 7.6 in 1999, 7.5 in 1976, 7 in 1964, two 7.1 quakes in 1957, 7.2 in 1953, 7.5 in 1944 and another 7.8 quake in 1939.
Turkey/Türkiye is no stranger to earthquakes. They are a continual, if not unwelcome, companion.
The alignment of planets has effective nothing to do with earthquakes. Any effect is very small.
The moon, sun, and other planets have an influence on the earth in the form of perturbations (small changes) to the gravitational field. The relative amount of influence is proportional to the objects mass, and inversely proportional to the third power of its distance from the earth.
There have been several planet-alignment scares. “The Jupiter Effect” (1974), by John Gribbin and Stephen Plagemann, predicted that a line-up on March 10, 1982, would cause catastrophes including a great earthquake on the San Andreas Fault.
That did not happen.
The following is multiple choice question (with options) to answer.
California experiences heavy earthquake activity due to | [
"errostion",
"techtonics",
"volcanic activity",
"fire"
] | B | a tectonic plate moves along a fault line |
OpenBookQA | OpenBookQA-1247 | astronomy, everyday-life, popular-science, climate-science
It is for much the same reason that Winter is colder than Autumn, even though they have the same amount of daylight hours.
The following is multiple choice question (with options) to answer.
The northern hemisphere experiences winter | [
"the month after March",
"the month after November",
"the month after August",
"the month after June"
] | B | January is during the winter in the northern hemisphere |
OpenBookQA | OpenBookQA-1248 | geophysics, sedimentology
Title: Does dirt compact itself over time? If so, how does this happen? If I were to bury something 10 feet (~3 metres) underground, with loose soil on top, would the ground naturally compact itself over time, until whatever I had buried has dirt tightly pressing against it on all sides?
What if I buried it 50 feet (~15 metres) underground?
If it exists, what is this compaction process called and how does it happen? Soil is a collection of various sized minerals grains, of various types of minerals produced by the weathering of rock. Typical soil minerals are clays, silts and sands.
The properties and behavior of different soil types depends of the composition of the soil: the proportion of clays, silts and sand in a soil. Sandy soils are well draining and clayey soils are sticky.
Between the grains of minerals that comprise a soil are spaces, called pores or pore spaces. The pores can be filled with either water or air, depending the location of water tables and wetting events like rain, snow melts or other forms of water inundation.
The density of a soil is dependent on the degree of compaction of the soil. For to a soil to be compacted, a stress has to be applied to the soil to realign the grains of soil which reduces the total volume of the pores and reduces the amount of air within the pores.
Consolidation of a soil occurs when pore space is reduced and water in a soil is displaced due to an applied stress.
Regarding having something buried and soil compacting around it over time, yes that will occur but it is a question of how much stress the soil experiences, the duration of time and the nature of the soil - sandy or clayey. Something buried for a day without any stresses not much will happen. But, something buried for thousands of years with people and animals walking over it, rain falling on the soil, vibrations from nearby human activity and an occasional earthquake all add to the stresses the soil will experience and increases the degree of compaction or consolidation over time.
The following is multiple choice question (with options) to answer.
When dirt has eroded, it takes on this pattern | [
"circular",
"grooved",
"hydration",
"folding"
] | B | soil loss causes grooves in soil |
OpenBookQA | OpenBookQA-1249 | forces, newtonian-gravity
Therefore, the conclusion is very intuitive: in order to lift a body of mass $m$ from the ground, one must provide an external force $F_E\ge m g$.
The following is multiple choice question (with options) to answer.
What causes objects that have mass to be pulled down? | [
"planetary pull",
"wind",
"water force",
"weight"
] | A | gravitational force causes objects that have mass to be pulled down on a planet |
OpenBookQA | OpenBookQA-1250 | evolution, zoology, adaptation
One answer that came to mind is domestic animals - the horse and dog in prehistory, the cat in ancient Egypt, etc. That seems too obvious on one hand, and on the other hand may not really be an answer, as there seems to be no indication that pre-domestic animals were endangered by humans in any meaningful way. Are there animals that have significantly adapted themselves to surviving as wild animals in human-influenced environments? Note: This is an answer to the last line of your question.
A classical example of animals adapting to the influence of humans on their environment is the adaption of the Peppered Moth.
Here is a brief summary:
The peppered moth was originally a mostly unpigmented animal (<1800). During the industrial revolution in the southern parts of the UK a lot of coal was burned. This led to soot blackening the countryside. Soon afterwards, a fully pigmented variety was first observed. Only a hundred years later, in 1895, this pigmented variety almost completely displaced the unpigmented variety.
It has been shown that the pigmentation is under strong selective pressure as birds hunt these moths. Since birds rely on their visual system to detect their prey, the variety that blends in with its environment (=camouflage) has a selective advantage over the variety that stands out.
As pointed out by Tim in the comments, since the 1970s there has been a rapid reversal with unpigmented animals being more abundant. As far as I understand, it is accepted that this reversal is due to a decrease in human induced air pollution leading to less sooty barks on trees which makes the unpigmented variety harder to prey upon.
Addendum: genetic basis of adaption
In a beautiful recent study, the causal mutation for the pigmented, or melanic, variety was identified: A ~9kb transposon insertion in the first intron of the gene cortex. The authors calculate that this mutation happened in the year 1819, a few years after the industrial revolution was in full swing. The interpretation is that due to sooty tree bark this mutation, causing pigmented moth, was under strong selection.
The following is multiple choice question (with options) to answer.
What is an example of endangered? | [
"deer are hunted to keep population levels in check",
"birds fly south for the winter",
"deer relocate in order to find better food",
"hawks hunt all of the mice from a field"
] | D | endangered means low in population |
OpenBookQA | OpenBookQA-1251 | 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.
Some animals are aided in finding food sources by | [
"aroma",
"neon signs",
"constellations",
"mating calls"
] | A | smell is used for finding food by some animals |
OpenBookQA | OpenBookQA-1252 | trees, forestry
Title: Why do some trees hold their leaves through fall and winter? Why do some species of oak (Quercus spp.) retain their leaves through fall and winter? I've found that these leaves are called marcescent leaves. There must be some benefit that the tree gains from this because it seems like it would increase the possibility of limb damage due to snow accumulation on the leaves. The trait might not necessarily allow for an advantage, but a few possibilities have been proposed:
Nutrient return to the soil when needed in the spring
Less palatability to grazing animals
Source:
http://northernwoodlands.org/articles/article/why-do-some-leaves-persist-on-beech-and-oak-trees-well-into-winter
The following is multiple choice question (with options) to answer.
If the leaves are removed from an oak tree, that can cause the tree to | [
"lose water",
"lose acorns",
"lose bark",
"lose energy"
] | D | a leaf performs photosynthesis |
OpenBookQA | OpenBookQA-1253 | mechanical-engineering, power-electronics
Title: How to choose an electronic connector/cable that works in a vibrating environment? We are designing a diagnostic electronic tool for a vibrating table.
In our PCB there are a gyroscope, an accelerometer and a bluetooth module.
Our PCB is attached to a vibrating table that works at 12 Hz with 10 mm peak-to-peak amplitude. It has to work for at least three years "always on".
When we are choosing the power connector, what are the technical elements we have to check before buying one? Are there special connectors for that specific use? "Vibrating-environment connectors"?
We are going to pot the pcb.
Our fear is that with that amplitude and with that frequency a normal soldered connector would fail and break itself. Use some type of strain relief on the power cable.
Clamp it down half an inch away from the connection point. That reduces the amount of flex on power connector.
The following is multiple choice question (with options) to answer.
Using rubber gloves when working on electronics can | [
"ruin the electronics completely",
"keep electricity moving quickly",
"keep electricity from moving as quickly",
"stop the electronics from ever working"
] | C | an electrical insulator slows the transfer of electricity |
OpenBookQA | OpenBookQA-1254 | pressure, fluid-statics
For example, suppose the water level is 5cm below the tops of the tube on both sides and 15cm above the bottom of the connecting tube. If you lower the reservoir (right side) by 10cm, the water level is lowered by 5cm. Relative to the tops of the tube, the water rises on the right by 5cm (so it is now level with the top) and lowers on the left by 5cm (so it is now 10cm from the top).
This operation can be done in 2 steps :
Cut off the top 5cm from the right side and add it to top of the left side, changing it from a U shape to a backward J shape. This alters the shape of the tube, and changes the water level relative to the tube but not relative to the laboratory.
Lower the altered tube by 5cm. This changes the water level relative to the laboratory.
The shape of the U tube has altered. The shape of the water has remained the same. All that has happened is that it is now 5cm lower. The water level is still 15cm above the bottom of the tube. Neither the volume of the tube nor that of the water have changed.
The following is multiple choice question (with options) to answer.
The amount of transpiration is lower in | [
"summer",
"fall",
"winter",
"spring"
] | C | transpiration usually happens in the leaves of a plant |
OpenBookQA | OpenBookQA-1255 | botany
Title: Do any plants exhibit hormonal changes similar to puberty? Just what the title states.
Are there any plants/trees that exhibit a growth spurt at a definite interval after the shoot appears? In flowering plants (the angiosperms) there are several developmental transitions in the life of the plant. I won't list the plants, because the list includes pretty much all of them (although the magnitude in the change of developmental pace differs widely between taxa and environments).
First there is seed germination, which is controlled hormonally. Absence of germination is usually imposed by abscisic acid, whilst germination is caused at the appropriate time by gibberellic acid and ethylene (among other things; Holdsworth, Bentsink & Soppe, 2008).
Next, in many herbaceous species there is a transition between a spreading growth stage (e.g. rosette growth) and the flowering stage. The 'growth spurt' here is the differentiation and elongation of the flowering stem, and then subsequently the sudden flowering of buds. The transition is also controlled hormonally, by a variety of hormones including auxin (Zhao, 2010), gibberellic acid, ethylene (Schaller, 2012), and the long anticipated, recently confirmed florigen (Choi, 2012). Ethylene and abscisic acid then play important roles in the next developmental transition when seeds and fruits are produced and dehisced.
Small RNAs are also now being revealed to play a large role in controlling the timing of developmental, but they are upstream of the hormonal changes. In particular some key miRNAs are involved in auxin-based regulation of branching, and in embryogenesis (Nodine & Bartel, 2010), and RNA silencing is involved in the switch from rosette growth to flowering growth (reviewed in Poethig, 2009 and Baurle & Dean 2006).
The following is multiple choice question (with options) to answer.
As the size of a flower increases | [
"more bees visit the flowers surrounding it",
"more honey makers will be drawn to the flower",
"the flower blooms anew",
"birds will eat the flower"
] | B | as the size of a flower increases , the number of pollinators it will attract increases |
OpenBookQA | OpenBookQA-1256 | 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 harmful phenomenon can cause atmospheric warming? | [
"gasses with pollution",
"acid rain",
"nuclear war",
"melting ice caps"
] | A | as the amount of polluting gasses in the atmoshere increases , the atmospheric temperature will increase |
OpenBookQA | OpenBookQA-1257 | organic-chemistry, physical-chemistry, biochemistry, alcohols
Title: Storage of Urine Not all may be favorable to this project, but I will explain what I am trying to do. I work at home, and instead of walking a moderate distance to the bathroom and loosing my focus, I've been, at times, peeing in a 3 Quart Poland Springs water bottle. If you take offense at this, please do not continue reading except to be helpful in the scientific goal. I know this subject won't suit many types of people, so just ignore it if that is your case.
I noticed first of all that urine is not at all as sterile as people say that it is. The rate of growth of bacteria is relatively slow, but as a precaution, I found the need to use additional measures to prevent the growth of bacteria. I settled on the following method: I have two bottles and I add to each bottle about enough salt as can be soluble in the urine and sometimes maybe a little more. The one bottle then fills up throughout the day and is emptied, washed, and refilled with salt. The salt helps to kill the bacteria which would be lingering in the empty bottle. The next day, the bottle stays empty and the other is used.
I would add that I discovered that the bacteria (without the salt) does not usually grow unless the bottle is left with urine for two days. After this, however, that same bottle (without the salt) would retain the bacteria and immediately grow, if used again.
This system works relatively well, so long as it is done every day. It will even withstand 2 days with only moderate growth. (If I should leave it by mistake for longer it can get ugly). Nevertheless, I am still looking to improve upon this. One reason is that, if I drink less water or relieve myself normally, the bottle does not fill in one day. I am looking for someone with knowledge of chemistry to help me find a substance that can be added to this solution which fits a number of common sense criteria. I will also add a list of the substances that I have tried or already considered.
Necessary qualities
The following is multiple choice question (with options) to answer.
What should I do to remain healthy | [
"Never move from my chair",
"Never talk to anyone",
"Eat burgers almost everyday",
"Make sure to get some shut lids"
] | D | a human requires rest to be healthy |
OpenBookQA | OpenBookQA-1258 | The above example has other implications. For example, what would happen if the disk hit very close to the nail? Obviously, a force would be exerted on the nail in the forward direction. So, when the stick is struck at the end farthest from the nail, a backward force is exerted on the nail, and when it is hit at the end nearest the nail, a forward force is exerted on the nail. Thus, striking it at a certain point in between produces no force on the nail. This intermediate point is known as the percussion point.
An analogous situation occurs in tennis as seen in Figure 10.27. If you hit a ball with the end of your racquet, the handle is pulled away from your hand. If you hit a ball much farther down, for example, on the shaft of the racquet, the handle is pushed into your palm. And if you hit the ball at the racquet's percussion point (what some people call the “sweet spot”), then little or no force is exerted on your hand, and there is less vibration, reducing chances of a tennis elbow. The same effect occurs for a baseball bat.
Figure 10.27 A disk hitting a stick is compared to a tennis ball being hit by a racquet. (a) When the ball strikes the racquet near the end, a backward force is exerted on the hand. (b) When the racquet is struck much farther down, a forward force is exerted on the hand. (c) When the racquet is struck at the percussion point, no force is delivered to the hand.
Order a print copy
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The following is multiple choice question (with options) to answer.
A person hits two drumsticks together and | [
"they light up",
"they fall apart",
"the insides quake",
"they burn"
] | C | tapping two objects together causes the particles in those objects to vibrate |
OpenBookQA | OpenBookQA-1259 | I solved it this way, any suggestions always welcome
c/b > 3/80 ( from question)
5/b > 3 / 80
(80 x 5 / 3) > b
This reduces to
133.3333 > b
So the number of burgers have to be less than 133.33 & as u dont get 0.33 burger in Mc Donalds Max burgers is 133
Give me a Big Kudoos Meal Combo if this helps
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Last edited by boomtangboy on 12 Mar 2012, 22:55, edited 1 time in total.
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Re: Chefs to burgers [#permalink] 12 Mar 2012, 22:49
boomtangboy wrote:
hi,
Give me a Big Kudoos Meal Combo if this helps
_________________
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Re: Chefs to burgers [#permalink] 12 Mar 2012, 23:10
budablasta wrote:
boomtangboy wrote:
hi,
Give me a Big Kudoos Meal Combo if this helps
Happy to Help
_________________
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The following is multiple choice question (with options) to answer.
A person wants to add some dill to their burger for dinner, so they would get it from | [
"a sawmill",
"a planter",
"a school",
"a cow"
] | B | plants are the source of spices |
OpenBookQA | OpenBookQA-1260 | the-sun, space, stellar-atmospheres
However, when you have something the Sun or even fog, the optical depth varies with the distance you're looking into that object. I'll talk about fog since it's familiar, but the same idea applies to the Sun's atmosphere. Say you're standing in a forrest and its very foggy out. There's a tree 1 meter away from you that you can see. You could measure your optical depth, $\tau$, of the fog between you and tree and might find that $\tau = 0.15$. Since $\tau$ is less than one, that implies you can see the tree, but the value of $\tau$ also implies how well you can see it. If $\tau = 0$, there's nothing between you and the tree to impede your ability to see it. Let's say there's another tree that's 5 meters away. Now there's more fog between you and the tree and while you can still see it, it is harder to see it. The optical depth of the fog between you and the tree 5 meters away might be $\tau = 0.75$. It's still less than one, implying the tree is visible, but because there's more fog between you and the tree, the optical depth is higher. Finally, there may be a tree 10 meters away with so much fog between you and the tree that the optical depth is $\tau = 1.5$. You can't see this tree because there's too much fog in the way. Hopefully you now realize that anything which is at a distance where $\tau > 1$ is not visible to you. That effectively defines a "surface" around you precisely when $\tau = 1$. Anything beyond that point is not visible and anything closer is visible.
If you're talking about the Sun, you can look at the Sun, but you'll only see light which originates from a point where $\tau < 1$. There are countless photons bouncing around inside the Sun, but you can't see them because they're in an opaque part of the Sun. Astronomers use the optical depth as a metric for defining the "surface" of the Sun.
The following is multiple choice question (with options) to answer.
Large trees block sunlight from reaching what? | [
"mountains",
"oceans",
"clouds",
"lower areas"
] | D | large trees block sunlight from reaching the ground |
OpenBookQA | OpenBookQA-1261 | 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.
A deer may be hungry and malnourished. In order to rectify this, the deer may | [
"eat other deer",
"consume boulders",
"consume cubs",
"consume dandelions"
] | D | eating food is used to get nutrients by living things |
OpenBookQA | OpenBookQA-1262 | 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.
Some pupa may | [
"Use wet towels",
"never happen",
"go into sand",
"Eat candy"
] | C | the cocoons being created occurs during the the pupa stage in a life cycle |
OpenBookQA | OpenBookQA-1263 | hydrology, rivers, dams
Title: Do dams reduce the flow of river downstream? There is a conflict between Egypt and Ethiopia, because the latter wants to build a dam on the Nile river. Citing this article:
[Egypt] fears the Nile dam will reduce its share of the river and leave the
country with dwindling options as it seeks to protect its main source
of fresh water.
What do they mean by "reduce its share of the river"? As far as I understand, the dam will create a reservoir, which will initially divert some water to be filled, but once that is done, the flow of the river should be the same. Is Egypt worried about this initial reduction, or do dams somehow reduce the flow of a river?
If so, what is the mechanism? I would guess that this is due to increased evaporation from the river, since the reservoir has a bigger surface than the usual river, but then again, it also collects more rain. Once a dam has been constructed in a river, the natural flow of water will be disrupted.
You correctly state that initially there will be a period required for the dam to fill. Until then, little of no water will flow beyond the dam.
Dams are created for one or more of three reasons:
To supply potable water to a population of humans for domestic or
industrial purposes.
For agricultural purposes.
To generate hydro-electricity.
The following is multiple choice question (with options) to answer.
What can be formed by damming a river? | [
"metals",
"H2O body",
"fires",
"mountains"
] | B | damming a river can cause a lake to form |
OpenBookQA | OpenBookQA-1264 | evolution, species
Title: Reasons why living fossils exist?
A living fossil is a living species (or clade) that
appears to be similar to another species otherwise known only from fossils,
typically with no close living relatives.
A living fossil is considered as a successful organism, which has made its way through many major extinction events. Also, the morphology of living fossils resemble some species of organisms which we know only through their fossil remains.
What is the reason for a particular type of species to become a living fossil; is the engineering of this particular species extraordinary, in that it can survive any selection process encountered thus far?
Is there not enough selection pressure exerted on this species in order to force it to change morphologically?
Have these organisms modified themselves, so that currently their morphology seems to be similar to a fossil organism? One part of your question betrays a serious error:
Is there not enough selection pressure exerted on this species in order to force it to change morphologically?
Actually the reverse is true; constancy of form can only be maintained in the presence of continuous selective pressure. It's just that this is stabilising selection that acts to maintain the existing form rather than push the organism to new morphologies. In fact, most selection acts in this manner. This shouldn't surprise you: organisms are typically well adapted to their environments so changes are more likely to reduce fitness than increase fitness.
It's also worth noting that although living fossils show little morphological change they can continue to show change at the molecular level at rates as high as, or higher than, other organisms - e.g. (May et al 2007; Cao et al 2013).
The following is multiple choice question (with options) to answer.
An example of a fossil is the bones of what kind of animal? | [
"toy",
"live",
"programmed",
"wiped out"
] | D | An example of a fossil is the bones of an extinct animal |
OpenBookQA | OpenBookQA-1265 | geology, geomorphology, coastal
Title: What causes such a narrow slit in a cliff? (see photo)
I have this photo as a background image and I often wonder how such a narrow, well-defined slit could be formed. Is it natural or man-made? If natural, what processes could have formed it? The rest of the coastline is rugged but this appears very uniform. It is on the north-west coast of Jersey (UK). If you see the other user (Jan Doggen's) google maps link, you can see apparently similar features in different states - this is a particularly neat example of a general phenomenon.
These notches form when headlands are undercut by caves carved out by the sea. They may be initiated where there is a fault or jointing in the rock (northwest Jersey is granite, according to google).
In this particular case, the notch seems to have a rounded termination. Blowholes also form from undercutting of headlands producing caves whose roofs then collapse. It's possible this cave may have collapsed after a blowhole formed, so you get a notch where the inland end of the feature appears rounded. That bit is just speculation though.
I found this Jersey geology trail guide that might have more detail: http://jerseygeologytrail.net/Geomorph.shtml
The following is multiple choice question (with options) to answer.
What are formed by natural geological processes? | [
"animals",
"lifeless matter",
"air flow",
"companies"
] | B | all minerals are formed by natural geological processes |
OpenBookQA | OpenBookQA-1266 | adaptation
Title: How do longleaf pine trees adapt to the florida keys rainforest? I know that longleaf pine trees can be found in rainforests, but I can't find anything. This is sort of a too broad question but here are a few ideas. The second most fragile part of plants are the leaves. In the latitudes and elevations that experience freezing, plants have learned to abscise their leaves and go dormant for the winter season. Conifers have thick, waxy, very thin leaves that most conifers do not need to shed.
In a rainforest there is no danger of too cold temperatures. That is why there is an abundance of broadleaf trees and plants in the rainforest. Most of our indoor plants are tropical rainforest species.
There is also an awful lot of rain in a rainforest. There is a problem with leaves covered with water, as it inhibits the absorption of CO2. Beneath the leaf, O2 is released as a by-product of photosynthesis. Broad leafed plants that have adapted to an environment with lots of rain, little wind, and being crowded together have leaves designed to 'wick' the rain water off the leaf to run down the midrib and off the pointy tip or lobed or curled under leaf margins. This clears off the water and allows the plant to take up CO2, or it would not be able to do photosynthesis to make its own food for energy.
The other cool thing I can remember, is that broad leafs of plants are able to 'adjust' to the light. Similar to a 'solar sail' in outer space. If in full sun, those leaves get thick and stay smaller. If in shade, very normal in a rainforest, those leaves can thin and get larger in order to capture as much light as possible.
A better wording for your question would be, 'why is there an abundance of broad leaf species versus conifers in a rainforest'? If I've been able to translate your question correctly?
Hope this helps.
The following is multiple choice question (with options) to answer.
what kind of changes in an environment will cause a plant to adapt to survive? | [
"new laws",
"lack of light",
"new poetry",
"loud music"
] | B | changes in an environment cause plants to adapt to survive |
OpenBookQA | OpenBookQA-1267 | reinforcement-learning, ai-design, control-theory
Without any proximity reward, you will rely on the wolf literally bumping into the rabbit through random behaviour, before it will have any data example that getting the vector between itself and the rabbit close to (0,0) is a good thing. You may need to have a relatively large capture radius, plus limit the area that the wolf (and eventually rabbit) can explore, in order to avoid very long sequences of random behaviour where nothing is learned initially.
The following is multiple choice question (with options) to answer.
A person in the woods who accidentally runs into a wild wolf will have little to fear because | [
"wolves love people",
"wolves carry people",
"wolves evade people",
"wolves smoke people"
] | C | animals usually distance themselves from humans |
OpenBookQA | OpenBookQA-1268 | 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.
Large Stag that are hunted prefer to live in the | [
"space",
"ocean",
"desert",
"timberland"
] | D | a deer lives in a forest |
OpenBookQA | OpenBookQA-1269 | meteorology, atmosphere, temperature
So, the temperature is falling over night after the sunset, but rises again after the sunrise. Thus, the temperature is at its lowest point in the morning.
Appendix for all you loving calculations:
Note: Simplified to toy model, no atmosphere
The cooling rate of the Earth is approximatelly given by the Stefan-Boltzmann equation:
$$j_E=\sigma\cdot T^4=5.670 \cdot 10^{-8} \frac{W}{m^2 K^4} \cdot (288.15 K)^4 = 390 \frac{W}{m^2}$$
The maximum heating rate of Sun in the zenith is $j_{\text{S max}}=1361 \frac{W}{m^2}$. So, the heating rate of Sun at altitude $\alpha$ is:
$$j_S=j_{\text{S max}}\cdot \sin{\alpha}=1361 \frac{W}{m^2}\cdot \sin{\alpha}$$
When is the heating rate equal to zero?
$$0=j_S-j_E=1361 \frac{W}{m^2}\cdot \sin{\alpha} - 390 \frac{W}{m^2}$$
$$1361 \frac{W}{m^2}\cdot \sin{\alpha} = 390 \frac{W}{m^2}$$
$$\alpha = 17 °$$
So, with our calculations, the minimum temperature is at the time when the altitude is equal to 17°.
The following is multiple choice question (with options) to answer.
The chillier time of the year below the equator occurs while above the equator is | [
"wearing thick coats",
"ice fishing",
"wearing swimsuits",
"adding blankets"
] | C | June is during the winter in the southern hemisphere |
OpenBookQA | OpenBookQA-1270 | geomorphology
Title: What causes these mound-like ground formations? Whilst riding on Mam Tor in Castleton, England I came across this scene (not my photo) and I would like to know what causes the formations which I have ringed in red. They look like piles of earth have been deposited a long time ago, but clearly that can't be the case, so what causes them?
Another image of these mounds They're landslide deposits; Mam Tor gets its name, which translates as "mother hill", from the regular landslides that come off the higher slopes and form hillocks further down into the valley.
The following is multiple choice question (with options) to answer.
torrential downpours can cause the side of a hill to become | [
"depressed",
"rock hard",
"greener",
"unstable"
] | D | storms can cause a landslide |
OpenBookQA | OpenBookQA-1271 | python, game
def check_win_diagonal(self):
"""
Returns a boolean indicating whether or not a diagonal win has occurred.
"""
ltr_diag = []
rtl_diag = []
i, j = 0, 3
for row in self.board:
ltr_diag += [row[i]]
rtl_diag += [row[j]]
i += 1
j -= 1
if (self.shared_attributes(ltr_diag) or
self.shared_attributes(rtl_diag)):
return True
return False
def player(self):
"""
Returns whose turn it is.
"""
if len(self.pieces)%2 == 0:
return 1
else:
return 2
def other_player(self):
"""
Returns the other person's turn.
"""
if len(self.pieces)%2 == 0:
return 2
else:
return 1
def print_board(self):
"""
Prints the board.
"""
for row in self.board:
pr = []
for piece in row:
if piece:
pr.append(piece.get_piece_abbr())
else:
pr.append(None)
print(pr)
def place_piece(self, piece, row, col):
"""
Places the piece in the specified location.
"""
if not self.board[row][col] and piece in self.pieces:
self.board[row][col] = piece
# del self.pieces[piece]
self.pieces.remove(piece)
return True
else:
return False
quarto_board = None
def initial_position():
"""
Initializes the board, which is a 4x4 2D array.
"""
return Board()
def primitive(state):
"""
Returns whether or not the current game is a TIE, WIN, or UNDECIDED.
This function takes in a state, which is an instance of Board.
"""
if (state.check_win_horizontal() or state.check_win_vertical() or
state.check_win_diagonal()):
return WIN
# no more pieces
if len(state.pieces) == 0:
return TIE
return UNDECIDED
The following is multiple choice question (with options) to answer.
An iron horseshoe with red stripes is held over a paperclip and | [
"melts it",
"drops it",
"burns it",
"yanks it"
] | D | a magnet attracts magnetic metals through magnetism |
OpenBookQA | OpenBookQA-1272 | electric-circuits, electricity, electric-current
Title: AC Current and Forward Movement Okay - maybe not the most advanced question, but one I have not seen a satisfactory answer to.
DC current is easy to understand. The current and electronics flow unidirectional, and you can understand how by connecting a circuit, a flow goes from the source to the recipient end of the circuit, and by passing through some form of resistance (say a filament on a light bulb), generates heat.
As for AC current, I get it. Once the circuit is on, the electrons pass back & forth. I understand that concept. What I do not understand is how the circuit ever gets created in the first place. Bear with me:
If ultimately, the current is flowing back and forth, how does it ever move forward from the source to the end-point of the circuit in the first place? I have heard of a golf-ball in a pipe analogy to explain how an AC circuit works... but what no one explains is how the current flows when first putting all the golf balls into the pipe in the first place (as an analogy).
Are the electrons already there (i.e. - a component of the material over which current flows)... but even then, if the current oscillates back-and-forth, how does it ever move forward to create a circuit?
The only analogy I thought of that might explain this is that the current itself (the flow of electricity) moves unidirectional, but the electrons oscillate. So an analogy in that case might be that the current is a river, while the electrons are fish swimming back and forth?
Apologies in advance for such a naive question, but this I have never been able to get a sufficient explanation for this. When an AC circuit is closed, the electric field moves through the wire at practically the speed of light. Since wires are conductors, there is approximately 1 free electron per atom of the conductor (usually copper), so there are always an ENORMOUS number of free electrons available to be accelerated by that electric field. The drift speed of each electron is very slow, even under the influence of the alternating electric field in an AC circuit, so the electrons are "sloshing" back and forth through a very small distance about a fixed point in the wire.
The following is multiple choice question (with options) to answer.
Electricity is able to flow through a circuit after it is...? | [
"Steady",
"fully complete",
"Turned on",
"Charged"
] | B | when an electrical conductor is plugged into an outlet , a circuit is completed |
OpenBookQA | OpenBookQA-1273 | # Thread: physics tourist & bear problem
1. ## physics tourist & bear problem
another easy one i think:
A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.5 m/s. The car is a distance d away. The bear is 27 m behind the tourist and running at 6.0 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
how many meters?
thanks alot.
2. Originally Posted by rcmango
another easy one i think:
A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.5 m/s. The car is a distance d away. The bear is 27 m behind the tourist and running at 6.0 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
how many meters?
thanks alot.
The maximum value of d is such that the bear gets to the car at the same time the tourist does.
So set up a coordinate system such that the bear is at the origin and positive x is in the direction from the bear to the tourist.
Both are moving at a constant speed. The bear has to cover 27 + d meters in the same time the tourist covers d meters.
So for the tourist:
[tex]d = v_t t = 3.5t[tex]
Thus
$t = \frac{d}{3.5}$
For the bear:
$27 + d = v_b t = 6 \left ( \frac{d}{3.5} \right )$
Now solve for d.
-Dan
3. Hello, rcmango!
Another approach . . .
A tourist being chased by an angry bear is running in a straight line
toward his car at a speed of 3.5 m/s. .The car is a distance $d$ meters away.
The bear is 27 meters behind the tourist and running at 6.0 m/s.
The tourist reaches the car safely.
What is the maximum possible value for $d$?
The tourist has a 27-meter headstart.
Relative to the tourist, the bear has a speed of 2.5 m/s.
To cover 27 meters, it takes the bear: . $\frac{27}{2.5} \:=\:10.8$ seconds.
The following is multiple choice question (with options) to answer.
A polar bear has thick wooly fur so that he may | [
"become a mop",
"showoff",
"clean the ice",
"thrive"
] | D | an animal requires warmth for survival |
OpenBookQA | OpenBookQA-1274 | water-resources, energy, renewable-energy, energy-storage
Title: Why do pumped storage hydroelectric facilities use bent pipes? When a reservoir is used to store water for electricity, it's pipes are usually laid in several segments on the ground to reach its source, such as a lake. It seems that if the pipes went directly to the lake by being suspended, less piping could be used and less energy lost due to friction would occur. Why are systems not built like this? Suspended pipes are heavy and need support - any change of direction also creates a force - and there is the aerial impediment to consider : Birds, parachutes planes etc.
Also some "pipes" are cut directly into the rock saving on material costs and consider that some of these pipes have a water flow rate of 45m3/s so the inertial forces are massive.
The following is multiple choice question (with options) to answer.
A system of tubes that relocates water and nutrients around in order to make most use of them can be found in | [
"a lily",
"a door",
"a table",
"a rock"
] | A | a plant stem contains a system of tubes for transporting water and nutrients to other parts of the plant |
OpenBookQA | OpenBookQA-1275 | acoustics, everyday-life
Title: What is the "wha" sound when you cover, uncover quickly your mouth,ears, or a speaker? I guess does it cause a doppler effect to sound? I have no idea what's going on These may not be just one thing.
If you uncover your ear you are almost certainly physically deforming your ear and creating pressure on the skin which may be generating some noise, and that close to your inner ear you'll notice tiny noises.
Uncovering your mouth to create that sound requires that you (again) be in contact with your skin and may be generating some low level noise (vibration) which is passed to your inner ear. You may also be generating some rapid (but small) air pressure change which you can hear.
To consider possible causes try blocking and releasing at different speeds and with different force. Even the very slightest rubbing of your ear will be audible to you.
Uncovering a speaker is likely to create a transient noise (if the speaker was active) or may simply be a pressure release (again depending on how you compress the air in the first place). As speakers are designed to generate sound based on the vibration of the material, any sudden vibration you cause in the material could cause sound.
@Asher's comment about air rushing past your hand. Yes you can probably hear this, but be careful to think about what you're actually hearing. If you use a small rigid object to rapidly pass it near your ear without touching your ear, you will hear the air. If you do with with you hand you may note that you'll detect other noises sometimes, which can be the physical contact of different parts of your hand with themselves.
A few quick experiments with a handy hand and ear (mine) suggest that just air movement is going to sound like a "woosh" (sort of no surprise there :-)) whereas a "wha" sound seems to require contact between surfaces and is a result of friction and/or physical deformation of something.
The following is multiple choice question (with options) to answer.
If someone hears a crunching sound while walking under a tree, which of these likely happened? | [
"dead leaves fell down",
"a mouse ran away",
"a duck started quacking",
"a dog was barking"
] | A | if a leaf falls off of a tree then that leaf is dead |
OpenBookQA | OpenBookQA-1276 | entomology, habitat
Title: Do hornets return to the same nest after winter each year? I have what I think is a hornet nest on the soffit of my house.
The nest has been removed, however, the hornets keep rebuilding. Also, they have started to swarm the sewer vent pipe (not shown in photo).
If fail to get rid of the hornets this fall, will they return to the same nest next year (or overwinter and continue to live there)?
I'm not sure if this is relevant or not:
To give you an idea of what kind of winters I am dealing with, I am near Toronto, Ontario; the temperature goes down to -25 degrees Celsius.
If fail to get rid of the hornets this fall, will they return to the same nest next year (or overwinter and continue to live there)?
No. The nest, likely made of wood pulp (and maybe mud), will/should degenerate to unusable over the winter, though the bulk could remain for a couple of years. All wasps die, except for the new queens (fertile, mated females) who overwinter in sheltered crevices somewhere.
In spring, it is a single wasp that starts a hive: the new queen. She builds a new, small hive in which to lay eggs, which is added to initially by the queen and then by workers who have hatched.
While she will not return to an old hive, the conditions which appeared advantageous to one queen (shelter from rain, intense sunlight, winds, etc.) will also seem advantageous to other queens, which is why nests appear in the same places year after year.
Edited to add: It appears most likely that the queens that overwinter are "new queens", that is, mated female offspring of the queen. H/T @Brian Krause.
The following is multiple choice question (with options) to answer.
Bumble Bees like to do what in the winter | [
"sleep years",
"sleep softly",
"sleep extensive periods",
"sleep painfully"
] | C | hibernation is an inherited behavior |
OpenBookQA | OpenBookQA-1277 | genetics, dna, chromosome, biotechnology, allele
Title: Do we come to know which allele is dominant by seeing family genration tree only? I know that a Gene has Alleles (variation) and one is Dominant over Other i.e the Other Recessive.
Then I got a Thought that How can we tell whether an Allele is Dominant or Recessive...... and I came across this Site while Googling, and It says we can tell this by Observing Patterns in the Family Generation Tree.
So, my question is that can we only describe an Allele by observing pattern? Is there any other Method or by looking at the Molecular level and tell?
Please extend this "How can we tell whether an Allele is Dominant" to a Special Case where a Gene has 3 Alleles.....can we have 2 Dominant Allele? Addressing Your First Question
We can tell whether an allele is dominant or recessive based on patterns in family trees, that is true, and it is very helpful! However, that is not the only way, since by looking at the molecular function of the alleles, the dominant and recessive relationship between alleles can be assessed without needing to look at family trees!
I think a deeper understanding of what it means to be dominant versus recessive would be helpful, because usually biology isn't just that simple! In most scenarios where there is a distinct recessive and dominant trait, it is because the dominant trait causes some specific activity/functioning protein while the recessive trait does not. Let's look at an example of this:
Let's choose eye color:1
There are multiple genes that affect eye color but let's just look at one: the one that codes for the brown pigment (melanin) to be produced in the iris [specifically the HERC2 gene]. As you probably already know, brown eyes are dominant and blue eyes are recessive.
The following is multiple choice question (with options) to answer.
Thee dominant trait will always be visible when | [
"either are missing",
"both are missing",
"both are present",
"the recessives present"
] | C | when both a dominant and recessive gene are present , the dominant trait will be visible |
OpenBookQA | OpenBookQA-1278 | A. 1
B. 2
C. 4
D. 5
E. 6
The trap: leftover jugs and/or empty spaces in one carton.
(1) Focus first on total number of jugs carried
Ignore the "7 jugs per carton" for now. It's crazy-making.
Instead, start by finding the total number of jugs carried by the worker in 17 trips
(4 jugs per trip) * (17 trips) = 68 jugs were carried
(2) Filled cartons? Partly filled cartons?
Now calculate how many cartons have been filled, and whether there are any partly filled cartons.
There must be 7 jugs in each carton
Divide 68 by 7 to get the number of cartons that are FULL, but pay attention to the remainder
$$\frac{68}{7}$$= 9 + remainder 5 jugs
So 9 cartons are full of 7 jugs, and one carton has only 5 in it.
A carton holds 7 jugs. The last carton needs 2 more jugs.
_________________
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A worker carries jugs of liquid soap from a production line to a packi [#permalink]
### Show Tags
17 Jun 2017, 09:42
6
5
The worker carried jugs of liquid soap(4 jugs/trip). So, in 17 trips, the worker would carry 68 jugs of liquid soap.
Since he can fill 7 jugs in a carton, he will need to add 2 more jugs
such that he has 70 jugs and he can fill the jugs in 10 cartons.
The following is multiple choice question (with options) to answer.
One example of avoiding waste when grocery shopping is to bring your own | [
"cloth satchel",
"greedy nature",
"one-use paper bags",
"disposable plastic bag"
] | A | An example of avoiding waste is using an object more than once |
OpenBookQA | OpenBookQA-1279 | geology
Title: Where do riverbed stones come from? Have they always been here since the river was formed? Are some newer than others? Riverbed 'stones' - I assume you mean things like pebbles, boulders, etc. are pieces of rock that have weathered out and been deposited in the river. Some come from rock that is very close to where they are located and some have been transported from very far away. In general (and it is a very broad generalization) the rounder the stone, the longer it has been in the river and the more likely it is to have come from far away. Of course that depends on the hardness of the rock, and other factors, too.
Some rocks are newer than others. Some have been formed quite recently and some are billions of years old.
The following is multiple choice question (with options) to answer.
A stone is weathered into sand in about | [
"a millennia",
"a week",
"a day",
"a fortnight"
] | A | weathering usually occurs over a period of many years |
OpenBookQA | OpenBookQA-1280 | c++, object-oriented, classes
}
std::cout << std::endl;
}
}
str Chess2::push(int row, int col, int desrow, int descol) {
using std::to_string;
str mystr = to_string(row) + to_string(col) + to_string(desrow) + to_string(descol);
return mystr;
}
str Chess2::computer_move(unsigned short int depth) {
str bestmove;
bestmove = miniMaxroot(depth, false);
std::cout << "Bestmove: " << bestmove << "\n";
perform(bestmove);
return bestmove;
}
The following is multiple choice question (with options) to answer.
Pushing an object requires what? | [
"wind",
"water",
"heavy exertion",
"flowers"
] | C | pushing an object requires force |
OpenBookQA | OpenBookQA-1281 | metabolism, ecology, photosynthesis
Title: Why isn't phosphorus or nitrogen a limiting nutrient for animals? Nitrogen and Phosphorus are usually the limiting nutrient for plants, especially for algae. Phosphorus is used for DNA, ATP and phospholipids, and Nitrogen is used for pretty much every protein a cell might want to produce. That is, their need for biological processes is not tied specifically to photosynthesis: anything that lives is going to need them, pretty much for anything it might want to do. It would make sense for them to be a limiting nutrient for almost anything that's trying to grow, plant or animal.
Yet for animals the limiting "nutrient" seems to always be energy, ie: food. Why aren't animals limited by lack of nutrients in the same way that plants are? Obviously animals need these nutrients, too. Or to reverse the question, why do plants need so much more phosphorus/nitrogen than animals do?
My best guess is that an animal's digestion of plant material is relatively inefficient energy-wise but relatively efficient nutrient-wise. So for an animal to eat enough food to have sufficient energy to survive, it's probably eaten more than enough Nitrogen and Phosphorus for its needs. But I'm just guessing and I can't find any data that would back up that guess. Phosphorus
Your suggestion that if we are meeting our calorific requirement we will be getting enough is true for phosphorus.
Most foods contain lots of phosphorus. The maximum dietary requirement occurs during adolescent growth, estimated at 1250 mg per day. Assuming a calorie intake of 2500 kcal we can calculate a 2500 kcal equivalent phosphorus content for various foods:
skimmed milk contains 7,400 mg phosphorus per 2500 kcal
roasted chicken breast contains 7,500 mg phosphorus per 2500 kcal
cooked white rice contains 3840 mg per 2500 kcal
(Calculations are based upon values obtained via this site.)
Nitrogen
Our requirement for nitrogen is met by our protein intake: inadequate protein intake manifests as kwashiorkor which is essentially due to a dietary deficiency of essential amino acids. In other words, the only way to achieve a nitrogen-deficient diet is to not eat protein, and this would not be alleviated by any inorganic source of nitrogen, even if we could consume enough of such a N source.
The following is multiple choice question (with options) to answer.
What are nutrients a source of energy for? | [
"water",
"whales",
"stars",
"plastids"
] | B | nutrients are a source of energy for living things |
OpenBookQA | OpenBookQA-1282 | zoology, physiology, brain, ethology, behaviour
Robins, A., Lippolis, G., Bisazza, A., Vallortigara, G. & Rogers, L. J. (1998). Lateralized agonistic responses and hindlimb use in toads. Animal Behaviour, 56, 875–881.
Rogers, L. J. & Andrew, R. J. (Eds) (2002). Comparative Vertebrate Lateralization. Cambridge: Cambridge University Press.
Roth, E. D. (2003). ‘Handedness’ in snakes? Lateralization of coiling behaviour in a cottonmouth, Agkistrodon piscivorus leucostoma, population. Animal behaviour, 66(2), 337-341.
Shine, R., Olsson, M. M., LeMaster, M. P., Moore, I. T., & Mason, R. T. (2000). Are snakes right-handed? Asymmetry in hemipenis size and usage in gartersnakes (Thamnophis sirtalis). Behavioral Ecology, 11(4), 411-415.
Sovrano, V. A., Rainoldi, C., Bisazza, A. & Vallortigara, G. (1999). Roots of brain specializations: preferential left-eye use during mirror-image inspection in six species of teleost fish. Behavioural Brain Research, 106, 175–180.
Sovrano, V. A., Bisazza, A. & Vallortigara, G. (2001). Lateralization of response to social stimuli in fishes: a comparison between different methods and species. Physiology & Behavior, 74, 237– 244.
Vallortigara, G., Rogers, L. J., Bisazza, A., Lippolis, G. & Robins, A. (1998). Complementary right and left hemifield use for predatory and agonistic behaviour in toads. NeuroReport, 9, 3341–3344.
Vallortigara, G., Rogers, L. J. & Bisazza, A. (1999). Possible evolutionary origins of cognitive brain lateralization. Brain Research Reviews, 30, 164–175.
The following is multiple choice question (with options) to answer.
Bats use the organs on the side of their heads to | [
"receive short radio pulses",
"hold up their sunglasses",
"create lift for flight",
"attract a potential mate"
] | A | bats can echolocate |
OpenBookQA | OpenBookQA-1283 | geology, geophysics, climate-change, carbon-cycle
We can see here in white numbers the most significant pre-industrial sources and sinks (at ~1000 years time scales). We can see that humans produce 9 Gigatons of carbon per year (GtC/yr), due to that extra inflow, photosynthesis is taking 3 GtC/yr more than before, and the ocean is taking an extra 2 GtC/yr as well. However, that is not enough to counteract the 9 GtC/yr we produce, and that is increasing the amount of carbon in the atmosphere at 4 GtC/yr. This means the level in the atmospheric "bath tub" is still rising.
If we were to keep those 9 GtC/yr we produce stable (i.e. not increasing production in the future). The concentration of $\ce{CO2}$ in the atmosphere will rise to a level high enough that the sinks will match the sources, for example with plants taking 5 GtC/yr and the ocean 4 GtC/yr, that would nicely balance the production. But that new equilibrium atmospheric $\ce{CO2}$ concentration would be high enough to rise Earth's temperature several degrees and force a whole reorganization of the Earth's climates.
Finally, we have to say that some of these $\ce{CO2}$ intakes, like the oceanic one, don't come for free, and have their own nasty consequences, like ocean acidification.
The following is multiple choice question (with options) to answer.
A person fills their tank with fossil fuels, and knows that in one hundred years | [
"they may be more bountiful",
"they may be more frequent",
"they may cease existing",
"they may be free"
] | C | fossil fuels are a nonrenewable resource |
OpenBookQA | OpenBookQA-1284 | atmospheric-chemistry
But some researchers have argued it does make a notable contribution in the lower atmosphere, but indirectly. There doesn't appear to be a consensus on how big this effect is (and the Wikipedia reference is old and obsolete). The argument for ozone being a notable contributor is based on the following. Hydrocarbon pollution in the lower atmosphere (often from vehicle emissions) leads to a variety of undesirable reactions some of which lead to the production of ozone (as well as many other irritating components of smog). We really don't want too much smog or ozone in the lower atmosphere because it is bad for health. Some have estimated that it also adds to the warming caused by hydrocarbon emissions (exacerbating the warming potential of methane, for example).
It is hard to judge the estimates of its contribution to warming not least because they rely on models of complex reactions caused indirectly by other pollutants. Also, the big issue with emissions leading to ozone are not its contribution to warming but its contribution to pollution which causes direct harm to people in the short term. In fact regulations around emissions has been striving to reduce those emissions since before we started worrying about global warming. And, many countries have sharply reduced them (this is a major reasons why most western countries insist on catalytic converters in their vehicles). We should reduce ozone pollution by reducing the other emissions that cause it and we have been doing that for decades.
I would argue that ozone is essentially irrelevant to global warming. We should strive to reduce it in the lower atmosphere even if we were not worried by global warming. So even if we can't agree on how big its contribution to warming is (which the literature isn't clear on) we should be reducing it as much as we can for more direct reasons.
And, even if we wanted to report its contribution to warming, the best place to account for it is to add it to the contribution of other emissions (eg methane) rather than to account for it separately as we don't directly emit it from anything.
The following is multiple choice question (with options) to answer.
If someone released a pollutant into the world, it would be all aside from | [
"plastic",
"poison",
"trees",
"smoke"
] | C | pollution is a source of pollutants |
OpenBookQA | OpenBookQA-1285 | species-identification, entomology
Title: Big Bug from Peru I'd like to have a name for this guy. There were 5 or 6 of them zipping around the flower bed on the coast of Peru about 120 kms south of Lima. That is a hawkmoth, probably Hyles annei (Guerin-Meneville, 1839). It is one of a number of moth species commonly called "hummingbird," "sphinx," or "hawk" moths in the family Sphingidae.
Beautiful, isn't it? :)
edit - sorry, I originally misidentified this as Hyles lineata - the pattern is slightly different.
The following is multiple choice question (with options) to answer.
Hummingbirds gather nectar using their | [
"bills",
"wings",
"hands",
"feet"
] | A | a skinny beak is used for obtaining food by a bird from small spaces |
OpenBookQA | OpenBookQA-1286 | home-experiment, oxidation-state
Title: the perfect campfire As far as chemistry goes, there are laws or observations that can be useful to determine the perfect shape and disposition of the wood in a campfire ?
For example what chemistry says about the 2 most popular "shapes"
teepee
log cabin
or even other variations such as the swedish stove ( 1 log with the top splitted in multiple segments )
The properties that I'm looking for:
- easy to start
- long lasting
The properties that I would like to have but I can discard:
- significant heat generation From many years as a trained firefighter, I can tell you that there is certainly science involved. There are a number of very heavy calculations for calculating things like solid combustible burn time and heat release rates for combustible materials, which might possibly be useful to predict the perfect shape, fuel size and arrangement for a campfire, but are probably well beyond the scope of producing the perfect sausage sizzle. However, a number of key factors that influence fire behaviour, and which must be considered in building the best campfire include:
The following is multiple choice question (with options) to answer.
At a campsite one night we all gather round a fire to roast marshmallows; this is an example of | [
"dinner",
"fusion",
"maillard reaction",
"competition"
] | C | cooking causes a chemical reaction |
OpenBookQA | OpenBookQA-1287 | 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.
What can genes do? | [
"Give a young goat hair that looks like its mother's hair",
"Make a baby chubby",
"Make a horse break its leg",
"Attack viruses and bacteria"
] | A | genes are a vehicle for passing inherited characteristics from parent to offspring |
OpenBookQA | OpenBookQA-1288 | \begin{align} \dbinom{6}{2} & \longleftrightarrow \dbinom{6}{6-2} \\[8pt] AB & \longleftrightarrow CDEF \\ AC & \longleftrightarrow BDEF \\ AD & \longleftrightarrow BCEF \\ AE & \longleftrightarrow BCDF \\ AF & \longleftrightarrow BCDE \\ BC & \longleftrightarrow ADEF \\ BD & \longleftrightarrow ACEF \\ BE & \longleftrightarrow ACDF \\ BF & \longleftrightarrow ACDE \\ CD & \longleftrightarrow ABEF \\ CE & \longleftrightarrow ABDF \\ CF & \longleftrightarrow ABDE \\ DE & \longleftrightarrow ABCF \\ DF & \longleftrightarrow ABCE \\ EF & \longleftrightarrow ABCD \end{align} There are exactly as many ways to choose $2$ out of $6$ as to choose $6-2$ out of $6$ because each way of choosing $2$ out of $6$ has a corresponding way of choosing $6-2$ out of $6$ and vice-versa.
• NOTE TO FUTURE USERS: This combined with TheSparkThatThought's answer and Ned's comment at the original question will guide you to the way someone must think. Jun 27 '14 at 23:12
Consider a collection of $n$ objects. Choosing $k$ of them to place into a set is equivalent to choosing $n-k$ to leave out.
Edit: Consider a high school dodgeball game with a red team and a blue team. There are $n$ total students, and the blue team has $k$ students. Since every student plays, there are $n-k$ students on the red team.
Because the PE teacher is biased, he lets the blue team pick all of their players first. They have $\binom{n}{k}$ ways to do this. After that, the red team has no choices. They must pick all of the remaining $n-k$ students.
The following is multiple choice question (with options) to answer.
A team has pizza after a game, and they eat most of it, but leave the rest of the pizza out. The pizza is later inedible because of | [
"need to play games",
"bedtime coming sooner than thought",
"lack of food preservation",
"exhaustion from the sun"
] | C | microorganisms cause food to spoil |
OpenBookQA | OpenBookQA-1289 | newtonian-mechanics, energy, friction, everyday-life
the main issue is friction and friction forces, which become torques
because of the structure of the devices considered;
talking of torque would necessarily require the description to
introduce size considerations (wheel and brakes radius), which
would complicate the analysis without bringing in any essential
insight regarding ABS;
this is just a qualitative analysis, without using any actual
figures. Developing complete formulae would of course require to
bring in size issues, and to consider torques. But I deemed it simpler
not to do that here.
To dissipate any misunderstanding and any heat that could result from
it, I should make it clear that this looked to me like an interesting
problem to work on, but that I have no particular expertise, and I did what I could with the information I could find. Comments and criticisms are welcome.
The following is multiple choice question (with options) to answer.
How might you figure out what a parts are needed to let your car drive? | [
"think very hard until you figure it out",
"ask the person who invented it",
"throw it in a lake and see if it floats",
"break it down and determine what it is composed of"
] | D | the composition of something can be used to identify that something |
OpenBookQA | OpenBookQA-1290 | = ",Count[Drop[branches,gen],_Real,\[Infinity]]/4" "" ""Length = ",SetAccuracy[Count[Drop[branches,gen],_Real,\[Infinity]]/4*(Norm[{{pt1[[1]],0.5},{0,0}}]^gen),3]}],18],Gray],{2.3,-1.8}]},{Inset[Style[Text@TraditionalForm@Style[Row[{"Polynomial Trees by Bernat Espigulé"}],18],Gray, Opacity[0.4]],{2.3,-2}]}},PlotRange->{{-1.7,3.7},{-2.1,1.5}},ImageSize->{1000,600},Background->Black]],{{th,0.025,"Thickness"},0.005,0.185},{{gen,12,"Generations"},Range[1,16], ControlType -> SetterBar},{{pt1,{0.5,0.5}},{-0.5,0.5},{0.5,0.5},Locator}]Jurassic Trees
The following is multiple choice question (with options) to answer.
You may use a tree to | [
"build a human",
"build a bench",
"build a car",
"build a computer"
] | B | trees are a renewable resource |
OpenBookQA | OpenBookQA-1291 | thermodynamics, visible-light, lenses
I forgot to mention that you can't heat the sample beyond about $5500\,K$ (which is the temperature of a black body that best fits the spectrum we receive at sea level). Of course, you need to know what you're doing to get anywhere close to this temperature.
The following is multiple choice question (with options) to answer.
A source of heat could be | [
"an ice cube",
"a fan",
"holding hands",
"a snowflake"
] | C | a radiator is a source of heat |
OpenBookQA | OpenBookQA-1292 | metabolism, ecology, photosynthesis
Title: Why isn't phosphorus or nitrogen a limiting nutrient for animals? Nitrogen and Phosphorus are usually the limiting nutrient for plants, especially for algae. Phosphorus is used for DNA, ATP and phospholipids, and Nitrogen is used for pretty much every protein a cell might want to produce. That is, their need for biological processes is not tied specifically to photosynthesis: anything that lives is going to need them, pretty much for anything it might want to do. It would make sense for them to be a limiting nutrient for almost anything that's trying to grow, plant or animal.
Yet for animals the limiting "nutrient" seems to always be energy, ie: food. Why aren't animals limited by lack of nutrients in the same way that plants are? Obviously animals need these nutrients, too. Or to reverse the question, why do plants need so much more phosphorus/nitrogen than animals do?
My best guess is that an animal's digestion of plant material is relatively inefficient energy-wise but relatively efficient nutrient-wise. So for an animal to eat enough food to have sufficient energy to survive, it's probably eaten more than enough Nitrogen and Phosphorus for its needs. But I'm just guessing and I can't find any data that would back up that guess. Phosphorus
Your suggestion that if we are meeting our calorific requirement we will be getting enough is true for phosphorus.
Most foods contain lots of phosphorus. The maximum dietary requirement occurs during adolescent growth, estimated at 1250 mg per day. Assuming a calorie intake of 2500 kcal we can calculate a 2500 kcal equivalent phosphorus content for various foods:
skimmed milk contains 7,400 mg phosphorus per 2500 kcal
roasted chicken breast contains 7,500 mg phosphorus per 2500 kcal
cooked white rice contains 3840 mg per 2500 kcal
(Calculations are based upon values obtained via this site.)
Nitrogen
Our requirement for nitrogen is met by our protein intake: inadequate protein intake manifests as kwashiorkor which is essentially due to a dietary deficiency of essential amino acids. In other words, the only way to achieve a nitrogen-deficient diet is to not eat protein, and this would not be alleviated by any inorganic source of nitrogen, even if we could consume enough of such a N source.
The following is multiple choice question (with options) to answer.
What contains nutrients for plants? | [
"dirt cheap",
"wind",
"ground minerals",
"soiled clothes"
] | C | soil contains nutrients for plants |
OpenBookQA | OpenBookQA-1293 | optics, visible-light, quantum-electrodynamics, reflection
Title: Is the glass made up of holes that let the light to go through it? The following passage has been extracted from the book "The Magic of Science-A.Frederick Collins" (1917):
Substances of all kinds
have pores or holes in them. A sponge has pores that can
be seen and so has cheese, be it
green or yellow; and so, too,
have glass and metals, but the
pores or holes in the latter are so
small that you couldn't see them
even with a high-powered microscope,
but in glass they are
large enough to let light go
through them and in metals they
are large enough to let electricity
flow through them.
The following passage has been extracted from the book "QED:The strage theory of light and matter-Richard P Feynman" (around 1983-1985):
There are several possible theories that you could make up to account for the partial reflection of light by glass. One of them is that 96% of the surface of the glass is "holes" that let the light through while the other 4% of the surface is covered by small "spots" of reflective material. Newton realized that this is not a possible explanation.
Aren't the two passages in contradiction with each other?
Frederick says that glass is made up of holes that facilitates the passage of light through it, on the other hand Feynman is not ready to come in agreement. I think Frederick is little sloppy. Isn't it? Today we know that Collins is wrong.
He appears to be unaware of Newton's finding, and of course, advances made after he wrote his book.
The following is multiple choice question (with options) to answer.
Light has the inability to shine through what? | [
"solid wood",
"glass",
"atmospheres",
"water"
] | A | no light shines through an opaque object |
OpenBookQA | OpenBookQA-1294 | plate-tectonics, rivers, paleogeography, coastal, mountain-building
As to the second question, your mention of the closure of the Tethyan Ocean leading to the Indian-Tibetan collision suggests that you already suspect (correctly) that the Ganges is a case in point. It's headwaters were originally in southwestern China, and it originally flowed westwards along the foot of the proto-Himalayas (what is now the high Himalayas)and out to the Indian Ocean somewhere in the vicinity of what is now the Indus basin in Pakistan. As continental collision progressed there was continental up-warping in what is now the Himachal Pradesh area of India. This reversed the Ganges drainage so that it now flows eastwards.
This has important modern implications, as it was the originally westward-flowing Ganges that brought arsenic from the marine Tethyan sediments of western China, and which is now the source of the arsenic groundwater problem over much of Bangladesh and adjacent areas.
See also my paper: http://link.springer.com/article/10.1007%2Fs10653-005-7102-9 But don't pay the exorbitant price! - I can send you the original text for free! :-)
The following is multiple choice question (with options) to answer.
A mighty river flows through an area for millennia. Afterwards, it can be noted that where there once were shallow rivers, there are now | [
"massive canyons",
"large bricks",
"old socks",
"small creeks"
] | A | most canyons are formed by flowing rivers through erosion over long periods of time |
OpenBookQA | OpenBookQA-1295 | dna, cloning, dna-isolation
If you do this, regular freezers are not cold enough to prevent freezer burn. This is what happens when you put a steak in to the freezer, wrapped in plastic even it will shrivel up and start to dry out as the water in the ice starts to sublime out of the package (the dry air in the freezer basically sucks the water out of the food). If this happens to your animal tissue, its probably not going to revive.
Scientific labs use -80C freezers and liquid nitrogen storage because the water turns into a glass and all biochemical reactions are basically stopped. (besides drying out, the enzymes like DNAse are still nominally functioning in the cells at -20C and even simple bacterial cells don't live for more than a year at -20C, much less mammalian cells). For preserving cell lines, liquid nitrogen is much more preferred. I would say that properly produced cell lines can theoretically revive after indefinite liquid nitrogen storage.
So that's a quick answer. Sorry to be a party pooper - things could change quite a bit in the next 20 years, but we just don't know how much. popping a paw in a baggie or some DNA extract into the freezer might work, but its hard to say for sure.
As far as the choice of where the DNA comes from in the animal, its true that skin cell lines are often producing imperfect animals - the DNA may be modified in the skin in various ways that cause the animal to be smaller, weaker, or even deformed compared to the donor. At this time all the protocols I see (and i could be wrong) are skin cells. I would expect that there is a better tissue to preserve, but that might be just a guess at this point. Its likely that in the next 20 years the choice of cell line from the donor will change quite a bit as well.
The following is multiple choice question (with options) to answer.
Taking a chicken leg from a deep freezer and placing it on a kitchen counter will | [
"cause it to die",
"cause it to unfreeze",
"cause it to freeze",
"cause it to corrode"
] | B | moving an object from a cool place to a warm place causes the object 's temperature to increase |
OpenBookQA | OpenBookQA-1296 | newtonian-mechanics, collision
1 - This answer is considering a system where the surface of the floor doesn't deform itself. If there's a trampoline instead of the floor and an object won't stick to it once it falls on it, it will bounce back. If there's sand instead of hard surface, any object falling in sand would behave like an object which falls on the hard surface and fails the 3rd step
2 - See "Clarifying the actual definition of elasticity. Is steel really more elastic than rubber?"
The following is multiple choice question (with options) to answer.
A ball rolling over carpet will go ______ than a ball rolling over concrete. | [
"slower",
"speedier",
"greater",
"faster"
] | A | as the roughness of something increases , the friction of that something will increase when its surface moves against another surface |
OpenBookQA | OpenBookQA-1297 | human-biology, mammals, lifespan, dogs, rodents
Gigantism:
Whilst the life expectancy for a species may be higher in general people with gigantism may live shorter lives than possible because of non-metabolic related reasons. For example many forms of gigantism are linked to hormones which promote cell division and growth which are also linked to forms of cancer.
The following is multiple choice question (with options) to answer.
Just like with humans, if another organism consumes more calories than it burns off, it will inevitably | [
"get fatter",
"run",
"fly",
"die"
] | A | as the amount of food an animal eats increases , the weight of that animal will increase |
OpenBookQA | OpenBookQA-1298 | everyday-life, velocity, flow
Title: When passed, why does my car 'rock' on the highway when I'm stopped, but not when I'm moving? I am the blue car in this scenario. If I am stopped on the highway and am passed by a car going fast (about 65 mph), I feel my car rock in the left/right direction. I think I understand why this happens: the wake of the red car in the air pushes my car back and forth.
But if I'm moving slowly forward (say 5 mph or less), I don't feel anything when the car passes. I would think that, if anything, the force would be stronger, because the velocity difference is now 70 mph. I'm moving slowly enough that the rocking would still be quite noticeable. Why don't I feel the rocking any more in this scenario?
The following is multiple choice question (with options) to answer.
Why did the roadrunner cross the desert road? | [
"to evade a polar bear",
"to evade a coyote",
"to dodge a tsunami",
"to outrun an avalanche"
] | B | some animals move quickly to escape predators |
OpenBookQA | OpenBookQA-1299 | general-relativity, cosmology
Annihilation of "dark photons" back into "our world" particles.
Scattering of "dark photons" off "our world" particle.
So your "dark photons" are not so dark in the end...
The following is multiple choice question (with options) to answer.
When you exit a dark film theater, the world | [
"looks darker",
"looks brighter",
"looks the same",
"looks more French"
] | B | when light enters the eye through the pupil , that light falls on the retina |
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The following is multiple choice question (with options) to answer.
A puppy may be taken away from people if they | [
"keep it outside lacking protection",
"play with it affectionately",
"feed it quality food",
"give it clean water"
] | A | an animal requires shelter |
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