1. Chapter 8
Meiosis

2. Meiosis
the process that produces haploid reproductive cells called gametes.

3. Meiosis Produce sperm and eggs
Have 23 chromosomes, half the genetic information as body cells.

4. Meiosis
Cells that prepare for meiosis go through G1, S, and G2 phases (same as mitosis)
Two cell divisions
Meiosis I and Meiosis II

5. Meiosis I (4 phases)
Occurs in the testes and ovaries – produces two cells

6. Meiosis I
Prophase I
Chromosomes line up next to their homologous partner – synapsis
Each pair of homologous chromosomes is called a tetrad
Crossing over occurs – helps produce a new mixture of genetic material

7. Meiosis I
Metaphase I

8. Meiosis I
Anaphase I (independent assortment)

9. Meiosis I
Telophase I and Cytokinesis I

10. Meiosis II ( 4 phases) produces 4 cells Prophase 2 Telophase 2
& Cytokinesis
Metaphase 2
Anaphase 2

12. Development of Gametes
Meiosis is the formation of sperm and egg cells
Spermatogenesis: makes 4 sperm cells
Oogenesis: makes 4 egg cells, but only 1 survives

13. Sexual Reproduction
The production of offspring through meiosis and the union of a sperm and an egg.
Offspring are genetically different from parents.
Enables species to adapt.