2. Chromosomes: Extra Practice First, lets go back and discuss diploid and haploid…then we’ll do some practice

3. Diploid Cells = Cells with the full set of chromosomes (2n) – Paired chromosomes Half of our chromosomes come from each parent (23 from each parent) Somatic (non-sex) cells are diploid Created by mitosis Ex: Skin, Muscle, Nerve, Blood Cells

4. What is the human diploid chromosome number? Remember…Diploid = total number of chromosomes Answer = 46

5. What is the human somatic chromosome number? Remember…Somatic cells are non-sex cells… …Somatic cells are diploid… …Diploid cells have the full set of chromosomes Answer = 46

6. How many chromosomes are in brain cells? Remember…Brain cells are non-sex cells… …Somatic cells are non-sex cells… …Somatic cells are diploid… …Diploid cells have the full set of chromosomes Answer = 46

7. Haploid Cells = Cells with ½ the total number of chromosomes (n) Gametes (sex cells) are the only haploid cells – Ex: Sperm, Egg, Pollen Chromosome number is reduced by meiosis How do humans get 46 chromosomes? Haploid sperm cell (23) + Haploid egg cell (23) = Diploid zygote (46)

8. These chromosomes are in the egg cell of mom. These chromosomes are in the sperm cell of dad. I’m half mom and half dad.

9. What is the human haploid chromosome number? Remember…Haploid = half number of chromosomes Answer = 23 chromosomes

10. What is the human gamete chromosome number? Remember…Gamete cells are sex cells… …Sex cells are haploid… …Haploid cells have ½ the set of chromosomes Answer = 23

11. How many chromosomes are in female egg cells? Remember…Egg cells are sex cells… …Sex cells are gametes… …Gamete cells are haploid… …Haploid cells have ½ the set of chromosomes Answer = 23

12. What is the diploid chromosome number? 42

13. What is the haploid chromosome number? 21

14. How many chromosomes would be in somatic cells? 42

15. How many chromosomes would be in brain cells? 42

16. How many chromosomes would be in gamete cells? 21

17. How many chromosomes would be in muscle cells? 42

18. How many chromosomes would be in sperm cells? 21

19. How many chromosomes would be in egg cells? 0- not female!

20. Is this a male or female rat? male

21. Is the organism male or female? __________ What is the chromosome # in…. Haploid cells? ________ Diploid cells? ________ In white blood cells? _______ In sperm cells? ____________ In somatic cells? ___________ In gamete cells? ___________ In muscle cells? ___________ In egg cells? ______________ In a zygote cell? ___________ male 24 48 24 48 24 48 0- not female! 48 Notice….24 pairs of chromosomes