Could you please explain why A is the correct answer ?
question:
When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface. The brief exposure of the seeds to sunlight stimulates receptors. Which have become highly sensitive to sunlight during the months the seeds were buried in the soil, and the stimulated receptors trigger germination. Without the prolonged darkness, followed by exposure to sunlight, the seeds do not germinate.
The statements above, if true, most strongly support which one of the following statements about a field that will be plowed in the spring and in which pigweed seeds have been buried in the soil all winter?
(A) Fewer pigweed plants will grow in the field if it is plowed only at night than if it is plowed during the day.
(B) Fewer pigweed plants will grow in the field if it is not plowed at all than if it is plowed only at night.
(C) Fewer pigweed plants will grow in the field if it is plowed just before sunrise than if it is plowed just after sunset.
(D) The pigweed seeds that are churned up to the surface of the soil during the plowing will not germinate unless they are redeposited under the surface of the soil.
(E) All of the pigweed seeds that are already on the surface of the soil before the field is plowed will germinate.
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- thiru_anand
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Re: cr question on "pigweed seeds" need help in explanation
The question stem tells us to take the statement as true. You can take these "facts" and apply them to the answer choices, eliminating answers that are not necessarily true (or that could be false).
When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface. The brief exposure of the seeds to sunlight stimulates receptors. Which have become highly sensitive to sunlight during the months the seeds were buried in the soil, and the stimulated receptors trigger germination. Without the prolonged darkness, followed by exposure to sunlight, the seeds do not germinate.
The statements above, if true, most strongly support which one of the following statements about a field that will be plowed in the spring and in which pigweed seeds have been buried in the soil all winter?
(A) Fewer pigweed plants will grow in the field if it is plowed only at night than if it is plowed during the day.
*From the previous statement, we know that exposure to sunlight after prolonged darkness is what causes the seeds to grow. Based on this, it is reasonable to assume that fewer seeds will germinate if the field is plowed only at night compared to only during the day. We can make this assumption because the sun is out during the daytime, but there is no sunlight at night, so a field that is plowed during the day will receive more sunlight than a field that is plowed at night. We can keep this answer choice as a contender, and move on to try to eliminate other answer choices we know can not be correct.
(B) Fewer pigweed plants will grow in the field if it is not plowed at all than if it is plowed only at night.
*Based on the statement, we only know that the seeds will grow when they are exposed to sunlight. If the field is not plowed or if it is plowed at night, we can assume that the seeds will not be exposed to sunlight and therefor will not grow. If no plants will grow in both scenarios given in this answer choice, then it must be wrong.
(C) Fewer pigweed plants will grow in the field if it is plowed just before sunrise than if it is plowed just after sunset.
*Again, we do not know what the outcome will be when there is no sunlight. All we know is that the seeds need sunlight to germinate, and based on this, no plants will germinate in either case in this answer choice. It can be eliminated.
(D) The pigweed seeds that are churned up to the surface of the soil during the plowing will not germinate unless they are redeposited under the surface of the soil.
*This answer choice may seem tempting, but remember we are looking for the answer choice that is most strongly supported by the statement above. The statement says that the seeds will be churned up to the surface AND redeposited under the surface. It does not give any information about what will happen to the seeds that aren't redeposited, and for all we know, all of the seeds are redeposited under the surface. We do not have enough information to determine whether or not seeds that are not redeposited under the surface will germinate.
(E) All of the pigweed seeds that are already on the surface of the soil before the field is plowed will germinate.
*This answer choice is not supported by the statement above. The statement only addresses seeds that had a prolonged period of darkness while buried in the ground. We can not say whether or not seeds already on the surface before the field is plowed will germinate, because we do not know if they went through a period of prolonged darkness before reaching the surface.
None of the other answer choices besides A are supported based on the information we are given. Because of this, A must be the correct answer.
When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface. The brief exposure of the seeds to sunlight stimulates receptors. Which have become highly sensitive to sunlight during the months the seeds were buried in the soil, and the stimulated receptors trigger germination. Without the prolonged darkness, followed by exposure to sunlight, the seeds do not germinate.
The statements above, if true, most strongly support which one of the following statements about a field that will be plowed in the spring and in which pigweed seeds have been buried in the soil all winter?
(A) Fewer pigweed plants will grow in the field if it is plowed only at night than if it is plowed during the day.
*From the previous statement, we know that exposure to sunlight after prolonged darkness is what causes the seeds to grow. Based on this, it is reasonable to assume that fewer seeds will germinate if the field is plowed only at night compared to only during the day. We can make this assumption because the sun is out during the daytime, but there is no sunlight at night, so a field that is plowed during the day will receive more sunlight than a field that is plowed at night. We can keep this answer choice as a contender, and move on to try to eliminate other answer choices we know can not be correct.
(B) Fewer pigweed plants will grow in the field if it is not plowed at all than if it is plowed only at night.
*Based on the statement, we only know that the seeds will grow when they are exposed to sunlight. If the field is not plowed or if it is plowed at night, we can assume that the seeds will not be exposed to sunlight and therefor will not grow. If no plants will grow in both scenarios given in this answer choice, then it must be wrong.
(C) Fewer pigweed plants will grow in the field if it is plowed just before sunrise than if it is plowed just after sunset.
*Again, we do not know what the outcome will be when there is no sunlight. All we know is that the seeds need sunlight to germinate, and based on this, no plants will germinate in either case in this answer choice. It can be eliminated.
(D) The pigweed seeds that are churned up to the surface of the soil during the plowing will not germinate unless they are redeposited under the surface of the soil.
*This answer choice may seem tempting, but remember we are looking for the answer choice that is most strongly supported by the statement above. The statement says that the seeds will be churned up to the surface AND redeposited under the surface. It does not give any information about what will happen to the seeds that aren't redeposited, and for all we know, all of the seeds are redeposited under the surface. We do not have enough information to determine whether or not seeds that are not redeposited under the surface will germinate.
(E) All of the pigweed seeds that are already on the surface of the soil before the field is plowed will germinate.
*This answer choice is not supported by the statement above. The statement only addresses seeds that had a prolonged period of darkness while buried in the ground. We can not say whether or not seeds already on the surface before the field is plowed will germinate, because we do not know if they went through a period of prolonged darkness before reaching the surface.
None of the other answer choices besides A are supported based on the information we are given. Because of this, A must be the correct answer.
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