1. Catalyst
1. Hemophilia (h) is a recessive genetic disorder carried on the X chromosome. If a man with hemophilia marries a woman who doesn’t have the disease, what percent of their sons will have hemophilia?

2. Catalyst
2. A man with type heterozygous A marries a woman with type O blood. What percent of their children will have type A blood?

3. Catalyst
3. Snapdragons can be red, white or pink. If two pink snapdragons are crossed, what percentage of their offspring will be white?

4. Agenda Notes – Karyotypes and Pedigrees Independent Practice
Practice problems
Independent Practice
Exit Ticket

5. Karyotypes and Pedigrees
I can analyze karyotypes and pedigrees.

6. Why must scientists observe a cell’s genetic material during mitosis?
Scientists can visualize the chromosomes in a cell by photographing them while they are condensed in mitosis.
Why must scientists observe a cell’s genetic material during mitosis?

7. A picture of chromosomes arranged in sets and according to size is called a karyotype.
Human karyotype
Humans have 2 sets of 23 chromosomes (46 in total).
each pair of chromosomes is homologous – they are the same size and contain the same genetic information

8. 23 Half (23) of your chromosomes come from your father…
from mom
from dad 23
…and half (23) come from your mother.
The fertilized egg, or zygote, has all 46 chromosomes necessary for life.

9. A picture of chromosomes arranged in sets and according to size is called a karyotype.
Human karyotype
The 23rd pair of chromosomes are sex chromosomes. They determine the sex of the individual.
females: XX
males: XY

10. Sex chromosomes X chromosome Y chromosome
The Y chromosome contains very few genes of importance, other than the SRY gene, which determines maleness.

11. A picture of chromosomes arranged in sets and according to size is called a karyotype.
Human karyotype
The remaining 22 pairs are called autosomes.

12. Dog karyotype

13. Mouse karyotype

14. XX XY Y X All human eggs carry an X chromosome.
after one round of meiosis…
All human eggs carry an X chromosome.
Sperm can contain an X or Y chromosome. XX XY
There is a 50% chance that the zygote produced from the fertilized egg is female (XX), and there is a 50% chance that it is male (XY).

15. What sex is this individual?
Karyotypes can tell us two important things: the sex of an individual, and whether there is a genetic disorder.
What sex is this individual?

16. What sex is this individual?
Karyotypes can tell us two important things: the sex of an individual, and whether there is a genetic disorder.
What sex is this individual?

17. What’s wrong with this individual?
If nondisjunction occurs during the formation of gametes, abnormal numbers of chromosomes result
Down Syndrome is the result of trisomy 21, or 3 copies of chromosome 21.

18. What’s wrong with this individual?
Klinefelter’s Syndrome (XXY)

19. What’s wrong with this individual?
Turner Syndrome (XO)

20. Pedigrees

21. Pedigree Symbols
Square = male
Circle = female

22. Label the Pedigree

23. Sons? Daughters? Children?
Color-blindness (h) is a recessive trait carried on the X chromosome. Using the pedigree to the right, what are the chances that they will have a color-blind child?
Sons? Daughters? Children?

25. Labeling the Pedigree 1 2 4 3 6 5 I II III P1 gen. I-2 XHXh
P1 (parent) 1 2 4 3 6 5 I
F1 (children) II
F1 gen.
II-4
XHY
F2 (children)
III

26. Agenda Notes – Karyotypes and Pedigrees Independent Practice
Practice problems
Independent Practice
Exit Ticket

27. Exit Ticket

28. Punnett Square Quiz