1. Meiosis
By: Mr. Meade

2. Body cells and gametes
2 major groups of cells: gametes and somatic cells.
Somatic cells are cells that make up the tissues and organs in your body.
Gametes are sex cells.
Ova in women
Spermatozoa in men

3. Body cells and gametes
Each species has a character number of chromosomes in every cell.
Chromosome # doesn’t relate to complexity.
Humans have 46 chromosomes, 23 pairs.

4. Autosomes and sex chromosomes
Humans have 46 chromosomes, 23 from mom and 23 from dad.
Homologous chromosomes are 2 chromosomes, 1 from each parent, that have the same length and appearance.

5. Autosomes and sex chromosomes
Scientists have assigned a number to each chromosome based on size from largest to smallest.
Chromosomes 1-22 make up your autosomes, or chromosomes not related to sex.

6. Autosomes and sex chromosomes
Sex chromosomes control sexual development.
XX are female
XY are male
The X chromosome is larger, so females contain genes that males are missing.

7. Diploid and haploid
Sexual reproduction is the process of fusing 2 gametes resulting in offspring.
Fertilization is when the sperm and egg’s nuclei fuse to form one nucleus.

8. Diploid and haploid
Diploid means a cell has 2 copies of each chromosome, 1 from each parent.
Humans have 46 diploid chromosomes.
Gametes are haploid, meaning each cell has one copy of each chromosome.

9. Diploid and haploid
So when the sperm and egg fuse, the off spring get 23 chromosomes from each parent.
Maintaining the correct number of chromosomes is important to the survival of each species.

10. Meiosis
Meiosis is a form of cell division of that divides diploid into haploid cells.
Germ cells (gametes) undergo the process of meiosis.

11. Meiosis
Homologous chromosomes are 2 separate chromosomes, 1 from each parent.
They carry the same genes, but are not copies of each other.

12. Meiosis Homologous chromosomes are divided in meiosis I.
Sister Chromatids are divided in meiosis II.

13. Meiosis I and II
Both stages of meiosis I and II have the same stages and the same as mitosis.
Prophase
Metaphase
Anaphase
Telophase

14. Compare and Contrast Mitosis with Meiosis