Sex Linkage

Question 1

Sex-linked diseases in humans

Answer 1

recessive or mutant alleles on the X chromosome will pass on: a mother with the allele will pass on the trait to her son.
this is because the allele will be fully expressed as:
* the Y chromosome has no corresponding allele
* Y chromosome is small and carries only genes that codes for traits of manliness

Question 2

Red-Green color blindness

Answer 2

• caused by a recessive mutation on the X chromosome
• much more common in men than woman

Question 4

Haemophilia

Answer 4

one of the protiens needed for blood clotting is missing
* Haemophilia A is where clotting factor VIII is missing
* Can be fatal if not treated, and even exercise causes internal bleeding
* affects mostly males, homozygous females are rarely able to survive birth as the homozygous alleles are fatal