Mitosis and Meiosis Glossary

Histone: Protein around which DNA is wrapped to form nucleosomes

Nucleosome: Bead-like structure of DNA wrapped around histones

Chromatin: Beads on a string-like structure of nucleosomes

Chromosome: Tightly packed chromatin

Haploid: Cells containing only one of each chromosome. In humans, this would mean 23 chromosomes. Only reproductive cells are haploid.

Diploid: Cells containing a pair of chromosomes. Humans have 23 pairs of chromosomes, making a total of 46 chromosomes. All cells except reproductive cells are diploid.

Gamete: Reproductive cells, ova in female humans and sperm in male humans

Sister chromatids: Identical copies of a chromosome, the sister chromatids are linked by the centromere. Once the sister chromatids separate during the later stages of cell division, they become individual chromosomes.

Homologous chromosomes: Humans have 23 pairs of chromosomes, one inherited from the father and one from the mother. These pairs consist of homologous chromosomes that carry the same genes.