In this task, you need to write a topic word from the given fact. The topic word must have at least one word overlap with the given fact. The topic word often involves adding a new word from a related concept. In your topic word, use at least one word from the given fact. Topic words with two or more words work best.

Q: Fact: Fungi are the only organisms that can decompose wood.

A: Fungi wood.
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Q: Fact: Gene flow occurs when individuals move into or out of a population.

A: Gene flow.
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Q: Fact: Sex hormones are chemical messengers that control sexual development and reproduction.

A:
chemical messengers carry signals.
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