Question

where female flies had to choose one of three side-chambers in which to lay eggs. all three side-chambers were the same except for the added scent of apple in side-chamber a, banana in side-chamber b, and cucumber in side-chamber c. only eggs deposited in side-chamber c were allowed to hatch and produce offspring. adult flies did not know which side-chamber was producing offspring. every day for 100 days, the researcher counted the number of flies in each side-chamber. by day 100, the number of flies in side-chamber c greatly increased, while the number of flies in side-chambers a and b had greatly decreased. which of the following statements best explains why there were more flies in side-chamber c, than in side-chambers a or b, on day 100? a more flies were entering side-chamber c because flies that prefer the scent of cucumber were artificially selected for. b more flies were entering side-chamber c because female flies learned which side-chamber allowed for successful reproduction. c more flies were entering side-chamber c because female fruit fly offspring produced in side-chambers a and b were less fit for the environment. d more flies were entering side-chamber c because male fruit fly offspring produced in side-chambers a and b were less fit for the environment.

Explanation:

• Option A: The setup involves allowing only eggs in chamber C to hatch, which is a form of artificial selection for flies that lay eggs in chamber C (prefer cucumber scent), as those in A/B don't reproduce. This matches the scenario.
• Option B: The problem states adult flies didn't know which chamber produced offspring, so they couldn't learn this. Eliminate B.
• Option C: The issue is about reproduction (eggs in A/B not hatching), not offspring fitness. Eliminate C.
• Option D: Similar to C, the key is reproduction (eggs not hatching), not male offspring fitness. Eliminate D.

Answer:

A. More flies were entering side - chamber C because flies that prefer the scent of cucumber were artificially selected for.