1. Mitosis & Meiosis Mitosis Meiosis Where does it occur?
In animals: all body cells except in the gamete or sex cells in the sex organs (gonads)
In Plants: root tips, shoot tips and cambium
Animal:
Gonads:
female: ovaries
Male: testes
Plants:
in egg (ovum and pollen
What is the Purpose
Growth & repair
Production of genetically identical cells
Production of gametes (sperm & egg) with haploid (1N) number of chromosomes
Production of genetically different cells
Describe the process
Ordinary cell division (asexual or growth division)
From one parent cell you get two identical daughter cells with the diploid number of chromosomes
Sexual or reduction divisions
From one parent cell in the gonads (sex organs) you get four gametes (4 egg or 4 sperm) with the haploid number of chromosomes.

2. Mitosis Parent Cell Chromosomes replicate
Spindle fibres become visible
Chromosomes line up at equator
Chromosomes pulled apart and move to opposite ends of the cell
Cell pinches to form new cells
Two new daughter cells formed with identical combinations of chromosomes
2N chromosomes

3. 1st stage of Meiosis Parent Cell Chromosomes replicate
Spindle fibres become visible
Chromosomes line up at equator
Chromosomes crossover: exchange segments creating new combinations of genes
Chromosomes pulled apart and move to opposite ends of the cell
Cell pinches to form new cells
Two new daughter cells formed with new combinations of chromosomes
2N chromosomes

4. 2nd stage of Meiosis 1:In each daughter cell Chromosomes do not
replicate
Spindle fibres become visible
Chromosomes line up at equator in each cell
Chromosomes separate and go to different ends of each cell. It is random as to which chromosome goes where.
Four unique gametes are formed , each with a different set of genes and only half the number of chromosomes.
1N chromosomes

5. Cell Division Concept Map nucleus Chromosomes Meiosis gametes Zygote
Mitosis
Egg
Sperm
undergo
produce
fertilisation
growth
Cell Division
Concept Map