1. Meiosis
& Some Mitosis

2. Review: What do we know about Mitosis?

3. Mitosis:
Makes more cells!
Begin with one cell, end with two!

4. Mitosis will help me grow!
Essential for growth and repair of plant, animal and human tissue.
Mitosis will help me grow!

5. Mitosis will heal my wounds.
The sooner mitosis happens… the sooner I can get this thing off my head.
Mitosis will heal my wounds.

6. Mitosis 1. Interphase 1. 2. Prophase 2. 3. Metaphase 3. 4. Anaphase 4.5.
5. Telophase 6.
6. Cytokinesis

7. Enough about mitosis…
what’s meiosis?

8. What is Meiosis? Makes more sex (reproductive) cells Sperm (in men)
Eggs (in women)

9. Who cares? No meiosis, no fertilization.
No fertilization, no offspring.
No offspring, no future.

10. Sperm cells carry genes that code for the father’s traits.
Meiosis in males:
Produces sperm cells in the testes
This process is called spermatogenesis
Sperm cells carry genes that code for the father’s traits.

11. Egg cells carry genes that code for the mother’s traits.
Meiosis in females:
Produces egg cells in the ovaries
This is called oogenesis
Egg cells carry genes that code for the mother’s traits.

12. Sperm and egg cells are:
Haploid (1n)
Reproductive Cells (x y)
Also called Gametes

13. Gametes?
Human Gametes are sperm and egg cells.

14. Refresher: What does haploid mean?
Daughter Cells have half the number of chromosomes than the parents (1n)

15. Result of Meiosis: 4 Haploid Daughter Cells!1 2 3 4

16. What’s a zygote? = +
Sperm Cell
Egg Cell
Zygote

17. Fertilization: Gametes combine to form a zygote.
We were all once a zygote!
The zygote will then divide through mitosis and grow into a living being.

18. Fertilization: = + Human 23 chromosomes (1n) 23 chromosomes (1n)

19. Other examples: = + 28 chromosomes (1n) 28 chromosomes (1n) 54

20. Other examples: = + 30 chromosomes (1n) 30 chromosomes (1n) 60

21. Other examples: = + 52 chromosomes (1n) 52 chromosomes (1n) 104

22. Recap: How is Meiosis different than Mitosis?

23. Meiosis Mitosis Makes more cells. Divide Once = Four Phases:
2 Diploid Cells (2n)
Four Phases:
Prophase
Metaphase
Anaphase
Telophase
Makes more sex cells. (Sperm & Egg)
Divide Twice=
4 Haploid Cells (1n)
Two Major Phases:
Meiosis I
Meiosis II

24. Please answer in complete sentences on a blank piece of paper.
Critical Thinking:
Please answer in complete sentences on a blank piece of paper.

25. Answer the following questions:
Explain a time when you have never felt so much pain. How did mitosis help you get through it?
Why do you think meiosis is important to production agriculture & animal science?