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: The hypothalamus and pituitary gland are located close together at the base of the brain. Answer: the brain

Output: The hypothalamus and pituitary gland are located near the base of this organ?

Input: Consider Input: Passage: A peptide is composed of two or more amino acids. Amino acids are the building blocks of peptides. Answer: amino acids
Output: What are the building blocks of peptides?