1. What are sex-linked traits?
Chapter 3.9
What are sex-linked traits?

2. Inherited traits
X and Y chromosomes carry genes (X chromosomes carry many genes, while Y chromosome carry few genes; thus the shape). Traits that are on these sex chromosomes are called ______________.

3. Sex-linked disorders
Some diseases are on ______ chromosomes. For example: hemophilia and colorblindness are sex-linked disorders.
________________is a disorder in which a person
the blood does not clot properly.
________________ is a disorder in which a person cannot see the difference between certain colors.

4. Hemophilia
Hemophilia- a person with hemophilia does not have a special protein that helps blood to clot. It can lead to bleeding, bruising, and even death.
The famous hemophiliac
was Queen Victoria of England.

5. Hemophilia

6. Colorblindness- these people can’t see numbers below

7. Sex-linked disorders
Sex-linked chromosomes are found more often in men than in women. It’s because of the gene being ____________.

8. Punnett Square for colorblindnessXC Y
XCXC
(normal)
XCY Xc
XCXc
XcY
(colorblind)
XC= normal
Xc= colorblind
Y =normal

9. Carriers
A woman who has one normal gene and the one sex-linked gene is called a ________. That woman appears to be normal. She still, however, can pass the gene for it to children.
All carriers have the heterozygous gene ex. XCXc, XAYa.

10. Pedigrees
_______________– chart that shows inheritance of certain traits over several generations. It’s like a family tree. Pedigree helps to see who has a disease and who is a carrier.

11. Pedigree

12. Checking concepts: What are sex-linked traits?

13. Why does a female with a gene for sex-linked disorder usually appear normal?

14. Why do more men have sex-linked disorders?

15. Why can’t a male be a carrier for hemophilia?

16. How can a female have the sex-linked disorder of hemophilia?

17. What kind of gene-pair in the female carrier of a sex-linked disorder?

18. What is the purpose of a pedigree?

19. Fill in blanks:
Traits that are inherited along with gender are called ___________ traits.
Most of the genes for sex-linked traits are found on the ____________ chromosome.
The genes for most sex-linked disorders are ____________.
A female who has a gene for a sex-linked disorder but does not show the disorder is a ______________.
A male who has a normal Y chromosome and an X chromosome for a sex-linked disorder _____________ have the disorder.