MEIOSISChapter 4.3

VOCABULARY Gametes:

Reproductive cells. They contain half the usual number of chromosomes.

Egg:Gamete that is formed by the female.

Sperm:Gamete that is formed by the male.

Fertilization:The process when the sperm and the egg

combine to form a new cell.

VOCABULARY Haploid Cell (Gametes):

A cell with half the DNA as a normal cell (23 single chromosomes for humans)

Diploid Cell:A cell with the normal number of chromosomes

(23 pairs, 46 total)

Why is it important to have haploid cells for reproduction? So they have the right number of

chromosomes. Get one set from each parent, creates diversity.

MEIOSIS A special kind of cell division that

produces gametes (haploid cells).

Only takes place in reproductive organs.

A single cell goes through two divisions (Meiosis I and Meiosis II)

They have half as much DNA so when they combine the new organism has the right number of chromosomes (23 from the sperm and 23 from the egg).

HOW MEIOSIS AND MITOSIS ARE DIFFERENT. Only cells that become gametes go

through meiosis.

Meiosis = 2 cell divisions Mitosis = 1 cell division

Meiosis = produces haploid cells (half as much genetic information) for reproduction.

Mitosis = produces diploid cells (same amount of genetic information as parent cell)