#21 - Global Reference, Must Be True, AP, Principle

[me2987a]

Whys is A incorrect in this question when it follows the passage in lines 17-25?

[James Finch]

Hi ME,

The problem with answer choice (A) is that it doesn't exactly track with what is said in lines 17-25; instead it gives a very concrete sequence of predator and prey population increases that seems to run counter to the information given in lines 6-14. These lines tell us that the it is first the cyclamen mites (prey) that infest the strawberry fields, then their Typhlodromus predators in the second year; the arrival of the predators means that the prey population never grows enough to devastate the strawberry crops. So the prey population grows first, with the predator population growing rapidly to counter the prey growth. This is the opposite of the sequence that (A) presents.

Contrast that to the correct answer choice, (D), which is supported by lines 23-37. In (D), the predator population must be responsive to the variations of the prey population, just as we are told that Typhlodromus is to the cyclamen mites.

Hope this helps!

[bella243]

Could someone please explain why E is wrong? Is it because the author never speaks about cases when pesticides should be used - just that they do more harm than good?

[evelineliu]

Hi Bella,

(E) is wrong because it's out of scope. The author's suggestion is simply to control pests with predators, but they do not provide information on what type of pesticides, if any, the predators can tolerate.

Hope that helps!
Eveline