Proto-Oncogenes

question 56

Multiple Choice

Proto-oncogenes

• A) code for proteins that promote the cell cycle.
• B) promote apoptosis.
• C) become tumor suppressor genes when mutated.
• D) are considered "loss-of-function" mutations.
• E) code for angiogenic growth factors.

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Definitions:

Prophase I

The first stage of meiosis I where homologous chromosomes pair up and exchange genetic material through recombination.

Chiasma

An X-shaped site in a tetrad usually marking the location where homologous (nonsister) chromatids previously crossed over.

Crossing-Over

A process in which genetic material (DNA) is exchanged between paired, homologous chromosomes.

Haploid Gamete

A reproductive cell, such as a sperm or egg, that contains a single set of chromosomes and thus only one allele for genetic traits.