Introduction to Mutation

What is a mutation

A heritable alteration in the nucleotide sequence of cellular DNA.

What is a point mutation

A mutation affecting a single base pair or a small number of adjacent base pairs.

What is a mutant

An organism or cell bearing a mutation that produces a phenotypic effect.

What is a phenotype

The observable traits of an organism or cell.

What is genetic variation

Differences in genetic information among individuals or cells.

What are the two major sources of genetic variation listed in the lecture

Mutation and recombination.

What is recombination

The formation of new combinations of genetic material, such as through crossing over during meiosis.

Why is mutation considered the ultimate source of evolutionary change

It creates new genetic variants that can be acted on by natural selection.

Why are mutants useful to geneticists

Studying mutants helps reveal gene functions and how genes influence phenotypes.

What is a spontaneous mutation

A mutation arising without an external mutagen, often through normal cellular processes.

What is an induced mutation

A mutation caused by exposure to a mutagen.

What is a mutagen

An agent that increases the likelihood of mutations.

What are the three broad classes of mutagens

Chemical, physical, and biological mutagens.

What are examples of physical mutagens

Ionizing radiation and non-ionizing radiation, such as ultraviolet (UV) light.

What are examples of biological mutagens

Transposable elements, viruses, and bacteria.

What is a somatic mutation

A mutation occurring in a non-reproductive body cell.

What is a germline mutation

A mutation occurring in cells that contribute to the production of gametes and may be inherited by offspring.

What is the difference between somatic and germline mutations

Somatic mutations generally affect the individual, while germline mutations can be transmitted to offspring.

Can mutations affect large amounts of DNA

Yes, mutations can affect small sequences, large DNA segments, whole chromosomes, or chromosome sets.