Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: Mutations have many possible causes. Some mutations occur when a mistake is made during DNA replication or transcription. Other mutations occur because of environmental factors. Anything in the environment that causes a mutation is known as a mutagen . Examples of mutagens are shown in Figure below . They include ultraviolet rays in sunlight, chemicals in cigarette smoke, and certain viruses and bacteria. Answer: mutation

Output: What is it called when a mistake occurs in dna replication.

Input: Consider Input: Passage: When a fluorine atom gains an electron, it becomes a negative fluoride ion. Answer: fluoride ion

Output: When a fluorine atom gains an electron, it becomes a negative what?

Input: Consider Input: Passage: Figure 7.8 Following meiosis, each gamete has one copy of each chromosome. Nondisjunction occurs when homologous chromosomes (meiosis I) or sister chromatids (meiosis II) fail to separate during meiosis. Answer: meiosis
Output: Each gamete will have one copy of each chromosome following which process involving cell division?