A normal female X H X H marries a man who has hemophilia.

What percentage of their sons will have hemophilia?

0%

Explanation:

Normal female genotype =

Genotype of a man with hemophilia =

Crossing the two in marriage:

  x  

Progeny:

The two sons from the cross have the genotype and are therefore free from hemophilia.

Hence, the percentage of their sons that will have hemophilia is zero (0).

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.