Sex Linked Traits

Question 1

Chromosomes

Answer 1

Egg has 23
Sperm has 23

Somatic cell has 46

They have homologous pairs

X-chromosomes are longer

Y-chromosomes are shorter

Female look like this
| |
| |

Male look like this

                         Egg 
                       X      X
   Sperm X    XX    XX
               Y    X       X

|
| i (Short)

Question 2

Genes hemophilia

Answer 2

AR gene: male pattern baldness
SRY Gene: Testes development

Hemophilia

Platelets make clots (spiky)
People with homophobia’s platelets don’t mesh closely enough

99% male

It’s recessive because females have two X chromosomes