Mitosis (Cambridge International IGCSE Science)

New Cells are Made by Mitosis: Extended

Extended Tier Only

• Most body cells have two copies of each chromosome

• We describe these cells as diploid

• When cells divide, the **replication of chromosomes happens beforehand **where chromosome numbers are doubled

• This ensures that when the** cell divides in two**, each new cell still has two copies of each chromosome (is still diploid)

• This type of cell division is known as mitosis and is used for:

  • growth
  • repair of damaged tissues
  • replacement of cells
  • asexual reproduction

• Mitosis is defined as:

Nuclear division giving rise to genetically identical cells

The process of cell division by mitosis

Exam Hint You are not required to know any of the stages of mitosis, only the key principles discussed on this page.