1. DO NOW
1.What is the correct number of autosomes and sex chromosomes in the somatic cell of a human male?
2. How many autosomes and sex chromosomes would be in the ovum of the human female?

2. 44 autosomes and 2 sex chromosomes(X and Y) 22 autosomes and an X
ANSWERS
44 autosomes and 2 sex chromosomes(X and Y)
22 autosomes and an X

3. WHAT DO YOU SEE?

4. WHAT DO
YOU SEE?
A person with normal color vision sees the number 5.

5. Color blindness (color vision deficiency)
is a condition in which certain colors cannot be distinguished, and is most commonly due to an inherited condition.
Problems in distinguishing reds and greens are the most common.

6. A pedigree for color-blindness
Normal male
Carrier female P1 F1
Color-blind male
Carrier female
Normal female
Normal male

7. Thomas Hunt Morgan was awarded the Nobel Prize in Physiology or Medicine in The work for which the prize was awarded was completed over a 17-year period at Columbia University, commencing in 1910 with his discovery of the white-eyed mutation in the fruit fly, Drosophila.

8. Morgan’s work with Drosophila demonstrated that genes for certain traits are located on the X chromosomes.
These genes are said to be sex-linked.
These genes do not appear to have corresponding alleles on the Y chromosome.
Since many sex-linked genes are recessive, they are expressed more frequently in males than in females.

10. XX x X’Y where X’=allele for white eye

11. Summary of Results
PARENTS
(Female: +) x (Male: W)
OFFSPRING
Phenotype Female: Male: +
Number TOTAL 10103
Proportion
Ratio :

12. X’X x XY where X’=allele for white eye

13. Summary of Results
PARENTS
(Female: +) x (Male: +)
OFFSPRING
Phenotype Female : Male: Male: W
Number TOTAL10044
Proportion
Ratio

14. HEMOPHILIA Hemophilia is often called the disease of kings
because it was carried by many members of
Europe’s royal family.

15. Queen Victoria
Queen Victoria of England was a carrier of hemophilia and passed The disease to many of her descendants (including the Russian emperor’s family and the Spanish royal family).

16. Family of Queen Victoria

17. The history of Queen Victoria's descendants illustrates the hereditary characteristics of hemophilia. We can take a look at her family tree(pedigree).

18. Explanation of the inheritance of hemophilia