AP BIOLOGY

Detailed explanation-1: -If she now marries a normal man then there will be 50% chances of her sons being colourblind. Since the son will receive the X chromosome from the mother and the Y chromosome from the father and one of the X chromosomes in the mother is normal and the other diseased.

Detailed explanation-2: -When a colour blind woman marries a normal visioned male, daughters will be carrier for this disease and all sons will be colour blind, this can be represented as follows: So, the correct answer is ‘All sons are colour blind, daughters carriers’.

Detailed explanation-3: -Final answer: A normal-visioned woman whose father was color-blind marries a color-blind man. Their fourth son may be color blind or may be of normal vision.

Detailed explanation-4: -It is a X linked recessive disorder. A man needs only one copy of a defective gene to be colour blind. A woman needs two copies of defective genes to be colour blind. So when a colour blind man marries a normal sight woman all of their sons will be normal but their daughters will be carriers.

Detailed explanation-5: -Each daughter has a 50% chance of being a carrier and each son has a 50% chance of being color blind.