Meiosis

Diploid

A cell with 2 full sets of chromosomes (2n); one set from mom and one set from dad.

Haploid

A cell with 1 full set of chromosomes (n); a combination of chromosomes from mom and dad.

Karyotype

A diagram that shows the number and visual appearance of the chromosomes in a cell.

Meiosis

The process of cell division that makes gametes in the gonads for sexual reproduction.

Sexual reproduction

The fusing of genetic information (gametes) from two parents to produce offspring that are a genetic mixture of both parents.

Fertilization

The actual fusion of egg and sperm to form a zygote.

Homologous chromosomes

Chromosome pairs that have the same types of genes (one from mom and one from dad).

Sister chromatids

Two identical copies of the same chromosome.

Somatic cells

Body cells that are diploid, meaning they have full copies of DNA (2 complete sets) in each cell.

Gametes

Sex cells (egg and sperm) that are haploid, meaning each cell only has half of the DNA (1 complete set).

Autosomes

Chromosomes that carry traits that determine individual characteristics; in humans, chromosomes 1-44.

Sex chromosomes

Chromosomes that specifically determine biological sex; in humans, chromosomes 45-46.

Meiosis I

The first meiotic division that separates homologous chromosome pairs, resulting in 2 haploid cells with duplicated chromosomes (sister chromatids).

Meiosis II

The second meiotic division that separates sister chromatids, leading to 4 haploid daughter cells with unduplicated chromosomes.

Crossing over

The process during meiosis that creates new combinations of genes, resulting in recombinant DNA, contributing to genetic diversity.

Mitosis

The process of cell division that produces identical diploid body cells for growth and repair.

Interphase

The phase before meiosis where the cell prepares for division with unduplicated chromosomes.

Prophase I

The phase in meiosis where homologous chromosomes pair up and crossing over may occur.

Metaphase I

The phase in meiosis where homologous chromosomes align in pairs at the center of the cell.

Anaphase I

The phase in meiosis where homologous chromosome pairs separate.

Telophase I

The phase in meiosis where nuclear membranes may reform after the first division.

Cytokinesis

The process where the cytoplasm divides to form separate cells.

Anaphase II

The phase in meiosis II where sister chromatids separate.

Telophase II

The phase in meiosis II where sister chromatids pull to opposite ends of the cells, and nuclear membranes start to reform.

Error in meiosis

A mistake that could be passed on to potential offspring in an egg or sperm.

Error in mitosis

A mistake that would primarily affect the parent cell and could lead to conditions such as cancer.