Critical Reasoning

As advertised on the main page of Beat the GMAT, Ashley, Brian, and I will be posting some original questions today and tomorrow with prizes for the first five students to respond with correct answers that show your work!

Good Luck!


Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors. Leaves changing colors in the autumn and falling from the trees is an example of planned or programmed senescence, in this case in response to changes in the photo-period or length of daily sunlight. Annual plants that die back in the winter and return in the spring also display programmed senescence. Unplanned senescence occurs as a result of external factors as well. For example, under watering a houseplant can cause the plant to die back in an attempt to survive the drought conditions. Curiously, overwatering can cause a similar response as the excess moisture in the soil prevents plant roots from breathing.

Which of the following conclusions is most supported by the statements above?

A) Programmed senescence always occurs as the result of changes in the photo-period.

B) Senescence is a process that only occurs in plants.

C) Both planned and unplanned senescence can occur due to changes in the external environment.

D) It is safer to underwater a plant rather than to overwater it.

E) There are some plants species that do not experience senescence.

A) Programmed senescence always occurs as the result of changes in the photo-period - Not true. Senescence as a result of photo period is an example of senescence.

B) Senescence is a process that only occurs in plants - Not true - this is not mentioned in the passage

C) Both planned and unplanned senescence can occur due to changes in the external environment - True - An example of planned and unplanned senescence due to external factors is provided in the passage

D) It is safer to underwater a plant rather than to overwater it. Not true - passage mentions underwatering and overwatering as possible reasons for senescence

E) There are some plants species that do not experience senescence. - Not true - not mentioned in passage

Right Answer - C

Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors. Leaves changing colors in the autumn and falling from the trees is an example of planned or programmed senescence, in this case in response to changes in the photo-period or length of daily sunlight. Annual plants that die back in the winter and return in the spring also display programmed senescence. Unplanned senescence occurs as a result of external factors as well. For example, under watering a houseplant can cause the plant to die back in an attempt to survive the drought conditions. Curiously, overwatering can cause a similar response as the excess moisture in the soil prevents plant roots from breathing.

Which of the following conclusions is most supported by the statements above?

A) Programmed senescence always occurs as the result of changes in the photo-period.
"always" too extreme, passage does not cover that

B) Senescence is a process that only occurs in plants.
although the passage talks about senescence in plants, it never states whether plants are the only specimen that undergo the process


C) Both planned and unplanned senescence can occur due to changes in the external environment.
correct answer, the first section provides examples of planned senescence (seasons) and the second segment provides examples of unplanned senescence (watering)

D) It is safer to underwater a plant rather than to overwater it.
way too irrelevant

E) There are some plants species that do not experience senescence.
the passage never covers this

IMO: C

A) Programmed senescence always occurs as the result of changes in the photo-period.

Incorrect because always is a strong word and programmed senescence is not always as the result of changes in photo period as mentioned in later part of the passage.

B) Senescence is a process that only occurs in plants.

Incorrect because only is too strong and passage didn't mention it senescence only occurs in plants.

C) Both planned and unplanned senescence can occur due to changes in the external environment.

Correct

D) It is safer to underwater a plant rather than to overwater it.

Incorrect as passage indicates both underwater and overwater will cause senescence.

E) There are some plants species that do not experience senescence.

Incorrect . This statement may be true but the passage doesn't provide any evidence to reach that conclusion.

C. Is the answer

Directly from the passage.....lines 2-3 and 10-11

Thanks for showing your work! Just submitting the answer will not qualify for the contest.

Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors. Leaves changing colors in the autumn and falling from the trees is an example of planned or programmed senescence, in this case in response to changes in the photo-period or length of daily sunlight. Annual plants that die back in the winter and return in the spring also display programmed senescence. Unplanned senescence occurs as a result of external factors as well. For example, under watering a houseplant can cause the plant to die back in an attempt to survive the drought conditions. Curiously, overwatering can cause a similar response as the excess moisture in the soil prevents plant roots from breathing.

Which of the following conclusions is most supported by the statements above?

A) Programmed senescence always occurs as the result of changes in the photo-period.

INCORRECT
the example furnished in the passage for the programmed senescence is a case of photo-period but it is not explicitly stated in the passage that Programmed senescence ALWAYS occurs as the result of changes in the photo-period.

B) Senescence is a process that only occurs in plants.

INCORRECT
It is explicitly mentioned in the passage that "Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors." we may draw an inference from this that Senescence occurs in other living beings also but in plants it refers "the dying back of a portion of the plant"

And it is nowhere mentioned in the passage that Senescence ONLY occurs in plants.

C) Both planned and unplanned senescence can occur due to changes in the external environment.

CORRECT
Supported by the passage. Examples for both the planned and unplanned factors are furnished in the passage.

D) It is safer to underwater a plant rather than to overwater it.

INCORRECT
The passage talks about both underwater and overwater a plant but no comparison is provided in the passage.

E) There are some plants species that do not experience senescence.

INCORRECT
Again Not mentioned in the passage.

Resubmitting the entry. (made few changes in the explanation for the correct answer choice C. made a silly mistake while typing the explanation as i was in a hurry to submit the reply)

Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors. Leaves changing colors in the autumn and falling from the trees is an example of planned or programmed senescence, in this case in response to changes in the photo-period or length of daily sunlight. Annual plants that die back in the winter and return in the spring also display programmed senescence. Unplanned senescence occurs as a result of external factors as well. For example, under watering a houseplant can cause the plant to die back in an attempt to survive the drought conditions. Curiously, overwatering can cause a similar response as the excess moisture in the soil prevents plant roots from breathing.

Which of the following conclusions is most supported by the statements above?

A) Programmed senescence always occurs as the result of changes in the photo-period.

INCORRECT
the example furnished in the passage for the programmed senescence is a case of photo-period but it is not explicitly stated in the passage that Programmed senescence ALWAYS occurs as the result of changes in the photo-period.

B) Senescence is a process that only occurs in plants.

INCORRECT
It is explicitly mentioned in the passage that "Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors." we may draw an inference from this that Senescence occurs in other living beings also but in plants it refers "the dying back of a portion of the plant"

And it is nowhere mentioned in the passage that Senescence ONLY occurs in plants.

C) Both planned and unplanned senescence can occur due to changes in the external environment.

CORRECT
Supported by the passage. Examples for both planned and unplanned Senescence due to changes in the external factors are furnished in the passage.

D) It is safer to underwater a plant rather than to overwater it.

INCORRECT
The passage talks about both underwater and overwater a plant but no comparison is provided in the passage.

E) There are some plants species that do not experience senescence.

INCORRECT
Again Not mentioned in the passage.

My answer is C as stated above.... I answered using a mobile device, where the lines were shorter and were shown as 2-3 and 10-11 but on my laptop browser, it looks like its line 1 and 3-4.

Conclusions:
The Given Passage is a description of changes in the colour, shape and other external changes in the leaves of a plant. The Passage explains that there are 2 types of senescence that can occur to plants, which are Planned or Programmed Senescence and Unplanned Senescence.

As answer C is in terms with the conclusion explained above, my answer is C.

IMHO C

The information offered by the passage is that Senescence, usually caused by changes in external factors, refers to the dying back of a portion of a plant.Furthermore, the passage goes on to elaborate planned or programmed senescence and unplanned senescence with examples.The correct answer must be supported by this information.

A) Programmed senescence always occurs as the result of changes in the photo-period. It is extreme. This is just one of the examples the author has provided for programmed senescence.

B) Senescence is a process that only occurs in plants. Again extreme. Nowhere does the argument provides evidence of senescence's exclusivity.

C) Both planned and unplanned senescence can occur due to changes in the external environment. Correct. The above paraphrase of the argument matches to this and the language is moderate.

D) It is safer to underwater a plant rather than to overwater it. Not mentioned in the passage.

E) There are some plants species that do not experience senescence. Out of scope

Which of the following conclusions is most supported by the statements above?

A) Programmed senescence always occurs as the result of changes in the photo-period.

Very strong wording. Safe to eliminate without reading the rest of the sentence

B) Senescence is a process that only occurs in plants.

Very strong wording. Safe to eliminate without reading the rest of the sentence

C) Both planned and unplanned senescence can occur due to changes in the external environment.

* May be .. lets keep reading... *

Reason 1)Process of elimination
Reason 2)Senescence in plants refers to the dying back of a portion of the plant usually in response to external factors. - supports the statement.

D) It is safer to underwater a plant rather than to overwater it.

No such information is provided in the passage to conclude it.

E) There are some plants species that do not experience senescence.

No such information is provided in the passage.

Thanks for posting the Q. Please let me know where to find other Q's.

A) Programmed senescence always occurs as the result of changes in the photo-period.
Incorrect because always is a strong word and programmed senescence is not always as the result of changes in photo period as mentioned in later part of the passage.

B) Senescence is a process that only occurs in plants.
Incorrect because although the passage talks about senescence in plants, it never states whether plants are the only specimen that undergo the process.

C) Both planned and unplanned senescence can occur due to changes in the external environment.
Correct answer, the first section provides examples of planned senescence (seasons) and the second segment provides examples of unplanned senescence (watering)

D) It is safer to underwater a plant rather than to overwater it.
Incorrect as passage indicates both underwater and overwater will cause senescence.

E) There are some plants species that do not experience senescence.
Incorrect . This statement may be true but the passage doesn't provide any evidence to reach that conclusion

Hence the Answer is C