Question

2. A man with type B blood mamies a woman with type A blood. Their first child has type o blood. The couple says this is

Answer 1

Blood types:

AB +

AB -

A +

A -

B +

B -

O +

O -

It is possible to have a child with O blood despite the parents having different blood types.

While the man tested for B blood, he could have been a combination between type o and B whereas, the woman was a combination of type A and o. Since A/B are dominant, they would 'stand out' contrarily to o.

This means that their children could have AB or O blood.

Answer 2

Answer:

This is possible, the rest of their family tree might have blood type O and it might have been past down in the generations to them and the sperm had blood type O

Edit: i just accidentally rated my own answer