Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: In binary fission, a cell splits in two. First, the large circular chromosome is copied. Then the cell divides to form two new daughter cells. Each has a copy of the parent cell's chromosome. Answer: two

Answer: In binary fission how many times does a cell split?

Question: Passage: The amount of material left over after a certain number of half-lives can be easily calculated. Answer: pheromone

Answer: What term is used to describe a chemical released by an animal that affects the behavior or physiology of animals of the same species?

Question: Passage: The deeper water of a lake makes up the profundal zone. There isn't enough light for photosynthesis in this zone, so most organisms here eat dead organisms that drift down from the water above. Organisms in the profundal zone may include clams, snails, and some species of fish. Answer: dead organisms

Answer:
What do most organisms eat in the profundal zone of a lake?