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.

Fact: mammals are endothermic. 
Question: what are endothermic?
mammals.

Fact: the excretory system is part of the life process. 
Question: What is part of the life process?
Excretory system.

Fact: random changes in genes create new genetic variation in the gene pool. 
Question: What creates new genetic variation in the gene pool?

random changes in genes.