Meiosis

• The process where gametes are formed

• 2 stages of cell division (some similarities to the phases in mitosis)

• The chromosome number of the daughter cell is half of the parent cell

• A gamete has n number of chromosomes (a hapliod number)

• Somatic cells (all other cells) have 2n number of chromosomes (a diploid number)

What is it?

Parents and Offspring

• In humans, the haploid chromosome number is 46, and the diploid number is 23

• Offspring have genetic information from both of their parents (23 from each)

• Each of the 23 chromosomes from the mother is matched with 23 chromosomes from the father

Meiosis

Homologous chromosomes

• Paired chromosomes are called homologous chromosomes

• Homologous chromosomes interact during meiosis and your characteristics are determined by how they interact

• This interaction is called crossing over and happens during prophase I of meiosis

Chromosome interaction

Fertilization

• During fertilization in humans, a haploid (n=23) sperm cell unites with a haploid (n=23) egg cell

• A diploid (2n=46) zygote is produced from this union

Zygote

Meiosis I

Meiosis II

END