The passage most strongly supports which one of the following statements about the mechanism by which cannibal spadef...

Ravi on April 26, 2019

@Steph,

Happy to help.

The question says, "The passage most strongly supports which one of
the following statements about the mechanism by which cannibal
spadefoot toad tadpoles recognize their kin?"

(B) says, "It is neither utilized nor possessed by those tadpoles that
do not become cannibalistic."

The problem with (B) is that we do not know anything about the
tadpoles who are not cannibalistic, so we can get rid of this choice.
We have no information from the passage about non-cannibalistic
tadpoles.

(A) says, "It is not dependent solely on the use of visual cues."

This answer choice is tricky because it's a negative statement.
However, the second paragraph of the passage never mentions anything
about visual cues. As a result, this is why (A) is the correct answer.
We know that the passage does say that the tadpoles can recognize
their kin through nipping at them. And, because nipping does not
depend on visual cues, we know that the mechanism is not solely
dependent on the use of visual cues. Thus, (A) is correct.

Does this make sense? Let us know if you have any more questions!

Roy on March 31 at 08:30PM

I was wondering about this questions as well.

If visual cues were not mentioned but nipping was, couldn't nipping be solely dependent on visual cues? I.E. If a tadpole can't see then it cant nip then it cant recognize it's kin. So, if this was true (which it could be since we don't know anything about sight from the passage, right?), wouldn't we be able to eliminate the middle term in the conditional statement and say that tadpoles rely solely on sight?

Emil on April 1 at 06:55PM

Hi, nipping as described in the passage is clearly not a visual act, but rather the act of biting (gently) another tadpole. Since nipping is a means of kin recognition, and nipping is not visual, their means of kin recognition must include at least on non visual aspect.