A Neutral Mutation

question 23

Multiple Choice

A neutral mutation

• A) is accumulated in small populations more rapidly than in large ones.
• B) is subject to strong selection.
• C) confers a selective advantage to an organism.
• D) is fixed in a population at a rate equal to the mutation rate.
• E) confers a selective disadvantage to the organism.

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Definitions:

Variant

An individual or group that exhibits differences in physical traits, behavior, or genetic composition from the typical or expected form.

Tumor-Suppressor Gene

A tumor-suppressor gene is a gene that suppresses cell growth and proliferation. Many tumor-suppressor genes are transcription factors activated by stress or DNA damage that arrest mitosis until DNA can be repaired. Mutations interfering with their expression can lead to excessive proliferation and cancer.

Oncogene

An oncogene is a normal gene whose function, when altered by mutation, has the potential to cause cancer.

BRCA1

A gene associated with a higher risk of breast and ovarian cancer when mutated; it plays a crucial role in DNA repair.