TASK DEFINITION: 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.
PROBLEM: Fact: when individuals move into or out of a population, it's random. 
Question: what is it when individuals move into or out of a population?

SOLUTION: random.

PROBLEM: Fact: animals with calcite shells form large colonies in shallow tropical water. 
Question: Animals with _ form large colonies in shallow tropical water?

SOLUTION: calcite shells.

PROBLEM: Fact: Using radioactive gamma ray sources, existing microorganisms in food can be killed. 
Question: Using radioactive gamma ray sources, existing microorganisms in food can be what?

SOLUTION:
killed.