Question

a scientist is studying two different kinds of the same species of fly that live around a lake. the scientist calls these two different kinds of flies type x and type y. both of these kinds of flies live near water and have in the same kinds of weather conditions. the two types of flies look similar, but type x flies are, on average, 20% larger than type y flies.

over a period of five years, deforestation occurred in an area about 50 km from the lake. this caused animals from those areas to move into wooded areas closer to the lake. the bar chart below shows data about the amount of deforestation that occurred in the nearby forest. the scientist collected population data on the flies. this data is shown in the graph below.

charts: fly populations (with type x and type y over 5 years) and deforestation (bar chart over 5 years)

which claim is supported by the given information?

a. flies with smaller body sizes were less able to survive when deforestation increased.

b. the effects of deforestation equally impacted both fly populations.

c. the effects of deforestation had a limited impact on either fly population.

d. flies with larger body sizes were less able to survive when deforestation increased.

Explanation:

1. Analyze the fly population data: Type X (larger) population decreases over years as deforestation (from the bar graph) increases. Type Y (smaller) population remains relatively stable.
2. Evaluate options:

• Option A: Type Y (smaller) population is stable, so this is incorrect.
• Option B: Type X population drops, Type Y is stable—impacts are not equal, so incorrect.
• Option C: Type X population has a significant drop, so impact is not limited, incorrect.
• Option D: Type X (larger) population decreases as deforestation increases, supporting this claim.

Answer:

D. Flies with larger body sizes were less able to survive when deforestation increased.