Cell Division

Introduction to cell division

Cell Division may be a challenging topic, but don't let it get you down!

Cell Division normally consists of two main components: the nuclear division (mitosis or meiosis) and cytokinesis. The main function of mitosis and meiosis is to ensure the correct number of chromosomes reach each of the daughter nuclei formed at the end of each process.

Mitosis occurs in somatic (non-reproductive) cells to create identical cells. This is important for growth, repair and asexual reproduction.

Meiosis occurs in germ cells to form sex cells (gametes), and is important in sexual reproduction. This creates gametes that contain a haploid number of chromosomes, which prevents the doubling of chromosome numbers when fertilisation occurs. This ensures that chromosome number is maintained in a species over many generations.

Learn the different stages of mitosis and meiosis through song. Check out my favourite music videos below.

Mitosis Song

Note that prophase can sometimes be subdivided into early prophase and late prophase.

This video refers to late prophase as prometaphase.

Remember:
cell division = nuclear division + cytokinesis

Meiosis Song

Meiosis can be subdivided into meiosis I and meiosis II.

The goal of meiosis I is to separate homologous chromosomes. Note how chromosomes paired up at the start in prophase I.

The goal of meiosis II is to separate sister chromatids.

Note: The video features crossing over, where non-sister chromatids exchange genetic material, resulting in some chromosomes being a mix of yellow and green in colour.