instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
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
answer:
What is it called when a mistake occurs in dna replication.

question:
Passage: A front forms at the boundary between two air masses. Types of fronts include cold, warm, occluded, and stationary fronts. Clouds, precipitation, and storms commonly occur along fronts. Answer: a front
answer:
What forms at the boundary between two air masses?

question:
Passage: 22.2.1 Lytic Cycle 1. Attachment: The virus binds to specific receptors on the host cell. Entry: There are two ways in which a virus can enter cells. Firstly, the virus can inject its nucleic acid into the host cell. Secondly, if a virus is contained in an envelope, the host cell can phagocytosise the entire virus particle into a vacuole. When the virus breaks out of the vacuole, it then releases its nucleic acid into the cell. Replication: The virus's nucleic acid instructs the host cell to replicate the virus's DNA or RNA. Assembly: New virus particles are assembled. Lysis and Release: The virus directs the production of an enzyme which damages the host cell wall, causing the host cell to swell and burst. The newly formed virus particles are now released. Answer: nucleic acid
answer:
What does a virus inject into the host cell?