Need explanation for this question (Bio)

Test Preparation AP Test Preparation
1

<li>The LEAST effective means of controlling pest species such as rats or roaches over a long period of time is generally to
A) limit food supplies
B) reduce the number of potential habitats
C) distribute pesticides throughout the habitat
D) introduce predators of the pest
E) introduce a disease which affects only the pest</li>
</ol>

<p>My initial reaction was natural selection for pests that displayed resistance/immunity against a disease or pesticide, since the question emphasized “over a long period”. From that, I narrowed it down to C or E, but couldn’t end up deciding between the two, and randomly chose E. The answer was C. Is some biological basis that would make C less effective than E?</p>

2

<p>Well I am going to go off some logic here and say that the disease has no guarantees of being spread consistently in the long run. But I dunno.</p>

3

<p>That would support E as the answer choice though, and that was partly why I chose E over C. For some reason C is correct though =/</p>

4

<p>C is correct because using pesticides only works well initially but not in the long term. When you use a pesticide it kills only like 95% of the rats/bugs because some are going to have immunity to the pesticide. These 5% that survive will then mate w/each other and produce offspring that are pretty much ALL immune to the pesticide. Therefore when you try to use the pesticide again it ends up being ineffective since most of the rats/bugs are immune to the pesticide. </p>

<p>Hope that helps. :)</p>

5

<p>C is also least likely because habitats can move.</p>

6

<p>I recognize this question. Is it from 2002?</p>

<p>Wouldn’t some rats also have an immunity to the supposed disease in (E), and the same problem would happen? Why is one less effective than the other?</p>