Write an incorrect answer to the given question based on the associated fact. You are also provided with the correct answer to the given question. Make sure that your incorrect answer is relevant and similar to the associated fact. Also, try to make the incorrect answer similar to the correct answer so that distinguishing the correct answer from the incorrect answer is not very easy. Make sure you don't accidentally provide another correct answer! Also, make sure they sound reasonable (e.g., might be on a school pop quiz). A good incorrect answer can be constructed using words associated with the question, but not the correct answer. For example, for the question "What helps plants survive?", using words like "weeds", "vase", "bee" (associated with "plant"), or "first aid", "parachute", "accident" (associated with "survive") etc. Your incorrect answers make the question hard, so these results in good incorrect answers.
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Question: Fact: Gene flow occurs when people move into or out of a population. 
Question: What happens when people flow into or out of a population? 
Correct Answer: gene flow.

Answer: gene expression.


Question: Fact: Traveling is a cause of air pollution. 
Question: What is a cause of air pollution? 
Correct Answer: traveling.

Answer: oxygen.


Question: Fact: some vertebrates have no hard tissues. 
Question: What do some vertebrates not have? 
Correct Answer: hard tissue.

Answer:
brains.