dihybrid cross part 2

The gene for haemophilia is recessive and is only present in the X chromosomes. Which of the two sexes are more prone to expressing this character?

• neither males nor females
• both males and females
• females
• males

a woman suffering from harmophilia has a _______ % chance of having a haemophilic son

• 100

• 75
• 50
• 25

A woman who is a carrier for colourblindness was married to a normal man. What is the possibility that this couple will have a colourblind daughter?

• 0/4

• 3/4
• 1/2
• 1/8

Can Y linked genes be inherited by the daughters from the father?

• Only if the father has a mutation
• Sometimes
• Yes
• No

what is mutation?

• Cell division
• Evolution
• change in number of cells

• Change in genetic material

A woman with blood group A has a father with blood group O. she was married to a man with blood group AB. What are the possible genotypes of the offsprings that this couple can have?

• BO, AB, AA

• AA, AB, AO

• AO, AB, BO

• AO, BO, AA,AB

Why is X linked inheritance called criss cross inheritance ?

• The trait is passed from a carrier mother to her sons, who then pass it on to their daughters.
• The trait is passed from a carrier father to his sons, who then pass it on to their daughters.
• The trait is passed from a carrier mother to her daughters, who then pass it on to their sons.
• The trait is passed from a carrier father to his daughters, who then pass it on to their sons.