1. Sex-Linked Traits Boy or Girl? The Y Chromosome “Decides” Y chromosome

3. What are Sex Linked Traits?
In 1910, Thomas Morgan discovered traits linked to sex chromosomes in fruit flies.
Some genes are attached to the X and Y chromosomes
EXAMPLE: In humans, colorblindness and hemophilia are found on the X chromosomes

4. What are Sex Linked Traits?
In Men, traits expressed anytime even one allele is present
In Women, must have two alleles to show trait
Children inherit color blindness from their mothers

5. Punnett Square: What sex will the offspring be?
50% chance of a male or a female child.

6. Hemophilia is carried by the mother
Phenotype:
25% hemophiliac males
25% carrier females
25% normal males
25% non-carrier, non-hemophiliac females

7. If Dad is color blind, will you be color blind?
Phenotype:
0% color blind males
100% color blindness carrier females

8. What if Mom is color blind?
Phenotype:
100% carrier females
100% color blind males