Anthony Azzolina Biology test Review

study guide

Meiosis

A special type of cell division that cuts the chromosome number in half and makes s3x cells (sperm or eggs)

Gamete

A s3x cell (sperm or egg) made through meiosis.

Gonad

The organ that makes gametes (testes make sperm, ovaries make eggs).

Chromatid

One copy of a chromosome after it has duplicated.

Chromosomes

Tightly packed bundles of DNA that carry your genetic information.

Gene

A small section of DNA that gives instructions for one trait or protein.

Allele

A version of a gene (like different flavors of the same gene).

Sister chomatids

Two identical chromatids stuck together after DNA is copied.

Homologous Chromosomes

A matching pair of chromosomes (one from mom, one from dad) that carry the same types of genes.

Haploid (n)

A cell with half the usual number of chromosomes (what gametes are).

Diploid (2n)

A cell with the full set of chromosomes (what most body cells are).

Spermatogenesis

The process of making sperm cells.

oogenesis

The process of making egg cells

Nondisjunction

When chromosomes don’t separate correctly during meiosis, leading to cells with too many or too few chromosomes

Tetrad

A group of four chromatids formed when homologous chromosomes pair up during meiosis.

Crossing-over

When homologous chromosomes swap pieces of DNA in meiosis, creating genetic variety.

Centrometre

The “center” spot where sister chromatids are held together.