instruction:
Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.
question:
Fact: Plants photosynthesize during the day but not during the night. 
Question: Plants do what during the day but not during the night?
answer:
photosynthesize.


question:
Fact: Mutations that lead to cancer usually occur in genes aiding in mitosis. 
Question: Mutations that lead to cancer usually effect genes that aid in what?
answer:
mitosis.


question:
Fact: water expands and increases in volume when it freezes. 
Question: What happens to water when it freezes?
answer:

Expands.