13. A family has four children: two girls and two boys. One girl and one boy are color-blind. Explain if their parents are color-blind and how you know. Can someone please help me?

Question

13.   A family has four children: two girls and two boys. One girl and one boy are color-blind. Explain if their parents are color-blind and how you know. Can someone please help me?

anonymous · Answer

one of the parents must have been heterozygous recessive for colour blindness while the other parent must have been colour blind. Lets say being able to see colours is indicated by CC and colour blindness is cc, then Cc would mean that the person has the trait for colour blindness although it is not manifested, it is recessive. Both parents would be Cc and cc giving them a 50% chance of having colour blind children. then you draw the usual table....comprende?

anonymous · Answer

I think I'm doing something wrong. I put CC for the dad and Cc for the mom and I'm coming up with all four recessive.

anonymous · Answer

If I am not mistaken some colour blindness are X-linked? So look at that possibility too.

anonymous · Answer

since both male and female have X it is bound to affect both, so it does not change the result much

anonymous · Answer

Out of four children if one daughter and one son have the trait then the trait would have to be homozygous in one parent and heterozygous carrier in the other I think.

anonymous · Answer

If I got cc for the father he would be colorblind wouldn't he?

anonymous · Answer

yeah

anonymous · Answer

"Out of four children if one daughter and one son have the trait then the trait would have to be homozygous in one parent and heterozygous carrier in the other I think."  this way only one child would be colour blind so no.

anonymous · Answer

Ok, I'm racking my brain because I can't remember how it worked out. thank you

anonymous · Answer

what you need is 2 kid that are colour blind not just carrying the trait

anonymous · Answer

get it now?