Gene Mutations and DNA Repair

These flashcards cover key terms and concepts related to gene mutations and DNA repair, focusing on definitions and characteristics relevant for understanding the subject for exam preparation.

Mutation

A heritable change in genetic information.

Somatic Mutation

A mutation in body cells that do not produce gametes.

Germ-line Mutation

A mutation in cells that will produce gametes, affecting future generations.

Base Substitution

Change in a single nucleotide of DNA.

Nonsense Mutation

A base substitution that creates a stop codon, leading to premature termination of translation.

Missense Mutation

A base substitution that results in a different amino acid.

Silent Mutation

A base substitution that creates a synonymous codon, resulting in no change in amino acid sequence.

Frameshift Mutation

A mutation caused by the insertion or deletion of nucleotides that disrupts the reading frame.

Induced Mutation

Mutations caused by environmental factors such as chemical agents or radiation.

DNA Repair

Processes that correct damaged DNA, including mismatch repair, direct repair, base-excision repair, and nucleotide-excision repair.

Mismatch Repair

A system that removes mismatched bases and replaces them with the correct base after DNA replication.

Direct Repair

Restores the correct structures of altered nucleotides.

Base-Excision Repair

Removes and replaces a damaged nucleotide.

Nucleotide-Excision Repair

Removes and replaces a section of DNA containing distortion.

Alkylating agent

A chemical that adds alkyl groups to nucleotide bases, increasing mutation rates.

Deamination

Loss of an amino group from a base, altering its pairing properties.

Homology Directed Repair

A pathway for repairing double-strand breaks that uses the same enzymes involved in recombination during meiosis.

Nonhomologous End Joining

A pathway for repairing double-strand breaks by random joining of broken chromosomal ends.