AP BIOLOGY

Detailed explanation-1: -A gene variant is a permanent change in the DNA sequence that makes up a gene. This type of genetic change used to be known as a gene mutation, but because changes in DNA do not always cause disease, it is thought that gene variant is a more accurate term.

Detailed explanation-2: -Mutations are almost permanent once you obtain them, with the only way to remove them entirely being to chug some Radaways. You can of course just expose yourself to more radiation to change your current mutation, however this just replaces one with another.

Detailed explanation-3: -When Replication Errors Become Mutations. Incorrectly paired nucleotides that still remain following mismatch repair become permanent mutations after the next cell division. This is because once such mistakes are established, the cell no longer recognizes them as errors.

Detailed explanation-4: -(myoo-TAY-shun) Any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect.