Mutation

Unit 10 Mutations

Mutation

A change in the nucleotide sequence of DNA.

Somatic mutations

Mutations occurring in somatic cells, which are not passed to offspring.

Gametes

Reproductive cells (eggs and sperm) that can carry mutations to offspring.

Chromosomal mutations

Mutations that involve changes in the structure of a chromosome or gain/loss of chromosome parts.

Gene mutations

Mutations that involve a change in the nucleotide sequence of a gene.

Deletion

A chromosomal mutation where a piece of a chromosome is lost due to breakage.

Inversion

A chromosomal mutation where a chromosome segment breaks off, flips around, and reattaches.

Duplication

A chromosomal mutation that occurs when a gene sequence is repeated.

Translocation

A chromosomal mutation involving the transfer of part of one chromosome to a non-homologous chromosome.

Nondisjunction

Failure of chromosomes to separate during meiosis, leading to gametes with abnormal numbers of chromosomes.

Point mutation

A gene mutation characterized by a change of one base, involving substitution, insertion, or deletion.

Substitution

A type of point mutation where one base is replaced with another.

Insertion

A type of gene mutation where a base is added to the nucleotide sequence.

Frameshift mutation

A mutation that involves inserting or deleting one or more nucleotides, altering the reading frame.

Reading frame

The way nucleotides are grouped into codons, affecting how amino acids are generated.

Amino acid sequence

The order of amino acids in a protein, which can be changed by mutations.

Somatic cells

Body cells that do not give rise to gametes and do not transmit mutations to offspring.

Beneficial mutations

Mutations that improve an organism's survival.

Leukemia

A cancer of the blood and bone marrow that can result from somatic mutations.

Chromosome structure

The composition and organization of a chromosome that can be altered by mutations.