SAT Subject Biology Practice Question 395: Answer and Explanation

Next steps

Question: 395

5. A community includes seven different populations with various degrees of interbreeding. Population 1 shares genes only with Population 2. Population 2 shares genes only with Population 1. Population 3 has no gene flow with other populations. Population 4 shares genes only with Population 5. Population 5 shares genes with Population 4, Population 6, and Population 7. Population 6 shares genes with Population 5 and Population 7. Population 7 shares genes with Population 5 and Population 6. Which population(s) is (are) most likely to evolve after a change in its environment?

A. Populations 1 and 2
B. Population 3
C. Population 4
D. Population 5
E. Populations 6 and 7

Correct Answer: D

Explanation:

D This question is intimidating because it seems so complex. Remember to take the question apart piece by piece-don't guess at an answer until you are sure what the question is asking! The best way to tackle this question is to draw a diagram of the interactions of the populations with one another. It might look something like this:

The question goes on to ask which population is most likely to evolve after a change-in other words, which population can best adapt to its new environment. You should know that evolution requires genetic variability, which is achieved through random mutation and through exchange of genetic material with other organisms (sexual reproduction). Clearly, the population that will be most likely to evolve is the one in which there is the greatest genetic variability. In this situation, that population is Population 5, because it interacts with the most other populations.

Previous       Next