Question

a team of marine biologists studied two different types of toothed whales that are of the same species. they called the whales type x and type y. type x whales have a relatively small range and stay in the same coastal region year - round. type y whales travel along the coast throughout the year and are migratory. both types of whales feed primarily on fish, particularly commercial fish like salmon.
the marine biologists tracked the population sizes of type x and type y whales for five years. this data is shown in the graph below. during this same time period, the scientists also recorded how much local fishing increased in the area each year. this data is shown in the table below.
graph: whale populations (x - axis: year 1 - 5, y - axis: number of whales; type x (blue) and type y (red) data points) and table: change in commercial fishing levels (year 1: n.a., year 2: 30%, year 3: 4%, year 4: 25%, year 5: 2%)
which claim is supported by the given information?
a. whales that are migratory had a survival advantage when commercial fishing increased.
b. whales that have a small habitat range developed a migratory behavior to gain a survival advantage.
c. whales that have a small habitat range were better able to survive when commercial fishing increased.
d. whales that are migratory avoided the commercial fishing regions to help other whales be able to survive.

Explanation:

1. Analyze Option A: Type Y (migratory) whales have a stable population, while Type X (small range) whales' population declines as fishing increases. This suggests migratory whales (Type Y) had a survival advantage with increased fishing.
2. Analyze Option B: The text says Type X has a small range and stays, Type Y is migratory. There's no info Type X developed migratory behavior. Eliminate B.
3. Analyze Option C: Type X's population drops with fishing increase, so small range whales were NOT better at surviving. Eliminate C.
4. Analyze Option D: No info that migratory whales avoided regions to help others. Eliminate D.

Answer:

A. Whales that are migratory had a survival advantage when commercial fishing increased.