Chapter 3 9 What are sexlinked traits Inherited

Chapter 3. 9 What are sex-linked traits?

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 _______.

Sex-linked disorders Some diseases are on ______ chromosomes. For example: hemophilia and colorblindness are sexlinked 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.

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.

Hemophilia

Colorblindness- these people can’t see numbers below

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

Punnett Square for colorblindness XC XC Xc Y XC XC (normal) XC Y (normal) XC Xc (normal) Xc Y (colorblind) XC= normal Xc= colorblind Y =normal

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. X C X c , X A Ya.

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.

Pedigree

Checking concepts: What are sex-linked traits?

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

Why do more men have sex-linked disorders?

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

How can a female have the sexlinked disorder of hemophilia?

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

What is the purpose of a pedigree?

Fill in blanks: 1. 2. 3. 4. 5. 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.