Mitosis and Meiosis

Mitosis is a type of cell division. Mitosis occurs wherever more cells are needed. It produces two new cells that are identical to each other, and to the parent cell. The process of growth and division is called the cell cycle. 

1. Chromosomes in the nucleus are copied. 2. Chromatids pulled apart and moved towards poles. 3. Chromosomes seperate 4. Cell divides.

Before a cell divides, its chromosomes are copied exactly. The DNA molecule is made of two strands. As each of the two strands separates, new strands are made alongside each of them, thereby making two new copies.

Meiosis is used to produce gametes. Meiosis is also known as reduction division.

1. Parent cell   2. Chromosomes make identical copies of themselves.   3. Similar chromosomes pair up   4. Sections of DNA get swapped.   5. Pairs of chromosomes divide   6.Chromosomes divide.

At fertilisation, the nuclei of the sperm and an egg join to form the zygote. The zygote contains 23 pairs of chromosomes - 23 single chromosomes from the sperm, and 23 single chromosomes from the egg, thereby creating the correct number of 46 chromosomes for all body cells. It also means the zygote contains a complete set of chromosomes from each parent.