Dead, rotting logs on the forest floor provide the habitat for a small

Question

Dead, rotting logs on the forest floor provide the habitat for a small mammal, the red-backed vole, which subsists almost entirely on the portion of certain specialized fungi that grows above ground. The fungi-spores are deposited on the forest floor by the voles. Some of the fungi that develop from these spores form underground sheaths around the fine roots of the growing trees and assist the trees by processing and sharing nutrients and producing an antibiotic that protects the trees from disease.

The information above provides the most support for which one of the following conclusions?

The information above provides the most support for which one of the following conclusions?

(A) The presence of rotting logs on a forest floor can have beneficial effects on the trees around them.
(B) The red-backed vole is usually able to derive nutrients from the spores of the fungi it eats.
(C) Young, growing trees could not survive without the voles to distribute the spores of certain fungi.
(D) The spores of certain fungi cannot remain viable above the ground but must be deposited near the roots of trees.
(E) Dead and decaying trees are the ideal environment for the growth of certain fungi.

AndrewN · Accepted Answer

Hello,  MsMaayan . I would be happy to offer my thoughts on the question to help you and the larger community. You have to be careful with questions that center on making an inference. It is easy to take an idea from the passage and let an association take over. How about we break down the passage and examine the answer choices?

Sentence one introduces  rotting logs  and  the red-backed vole  and informs us that this mammal  subsists almost entirely  on the above-ground parts of some fungi.   Sentence two bypasses a lengthy description of digestive processes to tell us, simply, that the voles then deposit the  fungi-spores... on the forest floor .   Sentence three shifts the focus to what goes on  underground : the spores form a symbiotic relationship with  growing trees —the spores process and share  nutrients  and produce  an antibiotic .

Do not take your eye off the key information provided, and you will stand to do well on these types of questions.

Take note of the soft language here:  can have , not  will have  or  always have . It is harder to debate a  can  than something more definitive. This answer choice effectively traces the passage map:

the presence of rotting logs on a forest floor  (line one) →  beneficial effects on the trees around them  (line three)

Of course, such a simplified version leaves out other factors, but those are understood within the context of the passage:

rotting logs → vole → eating of fungi/depositing of fungal spores → spore growth underground that benefits surrounding trees

Yes, we know that the vole  subsists almost entirely  on the fungi, but the passage goes out of its way to specify that the vole lives off of the  portion... that grows above ground . Do we know, without being mycologists, whether the vole consumes the fungi and derives nutrients  from the spores  in particular? I cannot point to anything in the passage to suggest as much. We cannot conflate subsisting on something and deriving nutrients from that same thing. A human, for example, can subsist on a single food, but that person might very well be lacking in nutrients.

Remember what I said above about soft language? Here, we see the opposite in a definitive  could not . All we know from the passage is that the vole plays its part in a certain process. We have no idea what growth conditions for young trees may look like outside of this narrow description— could not survive  is an overstatement.

Again,  cannot  and  must be  are overreaching in the absence of further information. Stick to the passage, not to one-step-removed associations.

Another bold declaration, even if  are  and  ideal  may not be as obvious as  must be . The passage tells us about one type of environment that fosters  the growth of certain fungi , but there is no comparison between this environment and any other, so labeling one  the best  or  ideal  is too much of a stretch.

This question forces us to consider the exact language of the passage and answer choices, as many tougher official questions do. Our goal is not to chase a could-be-true option, but to get behind the safest bet of the five, and here, the information in answer choice (A) and the language used to convey that information are the most justifiable or least debatable.

Perhaps the question makes more sense. Good luck with your studies.

- Andrew

MsDavey · Answer

Can you explain why the correct answer is A?

Niv19 · Answer

B) The passage stated the the red-backed vole subsists on the fungi, and that the fungi share nutrients with the tree. Hence this is not the best choice

C) We can conclude only that the fungi is deposited on the forest floor by the voles not that it the only way for it to be deposited in the floor. Further the fungi assit the trees, but there is nothing to assume that the tree would not thrive without them.

D) The word specialised can mean that this fungi is special because it grows above the ground or for any other reason. Since it isn't explicitly stated, we can't make this assumption.

E) The passage only mentions that that dead logs provide habitat for the vole. And since the vole subsists on the fungi. We can infer the fungi grows on the dead logs but there is no evidence that this is the ideal environment for the fungi.

A) This is the best choice as we can conclude for certain that the fungi CAN help the tree around them. Which is consistent with the wording in the passage.

Posted from my mobile device

VerbalBot · Answer

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Dead, rotting logs on the forest floor provide the habitat for a small

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