A Little More Help Pleeeeeze. Final Tomorrow?!
Question: A Little More Help Pleeeeeze!. Final Tomorrow!?
Hemophilia is a recessive, X-linked disorder in which the gene for a particular blood clotting protein is mutated such that the protein either is not made or does not work!. Two parents have 2 sons one is affected by hemophilia, what are the chances the other son will be affected!?Www@Answer-Health@Com
Answers:
if it is recessive (with both parents )then there is usually a 100% chance!.
bb bb
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bb/bb bb
bb/bb bb
But lets say one parent has a Bb gene (dominant, B meaning no haemophilia)!. There is a 25% chance
Bb bb
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bb/Bb bb
bb/Bb bb
In the case of haemophlia only the mother carries the Bb gene, your answer would be 50% because half of the punnet square is female, the other half is male!. Considering only males can have haemophila, you are only looking at half of the square!. You would not consider females because they have XY chromesomes which means its impossible for them to get haemophila
50%Www@Answer-Health@Com
bb bb
-------------
bb/bb bb
bb/bb bb
But lets say one parent has a Bb gene (dominant, B meaning no haemophilia)!. There is a 25% chance
Bb bb
----------------
bb/Bb bb
bb/Bb bb
In the case of haemophlia only the mother carries the Bb gene, your answer would be 50% because half of the punnet square is female, the other half is male!. Considering only males can have haemophila, you are only looking at half of the square!. You would not consider females because they have XY chromesomes which means its impossible for them to get haemophila
50%Www@Answer-Health@Com
Actually it's 50%!. This assumes dad is unaffected!. Here's why: draw out your punnet square!. Mom is X-h, X-H, and Dad is X-H, Y (h - being recessive gene for hemophilia)!. For them to get a son, he'll either by X-h (from mom) and Y (from dad) or he'll be X-H (from mom) and Y (from dad)!. The other side of your punnet square will only be girls!. Thus, for any sons they have, they have a 50% chance of him having hemophilia!. For daughters, she'll have a 50% chance of being a carrier!. If you look at all 4 possibilities in your punnet square, they have an overall 25% chance of having a child (male or female) with hemophilia!. Hope this helps!Www@Answer-Health@Com
XY is male right!?
im a little crusty on my biology!.
do we not need to know which parent was the carrier!?
hmm let me see, the father of XhY cannot give it to his sons!. the mother must be a carrier!.
the girl on top of me is right!. if looking at JUST sons then it is 1/2!. if looking at ALL the children it is 1/4!.Www@Answer-Health@Com
im a little crusty on my biology!.
do we not need to know which parent was the carrier!?
hmm let me see, the father of XhY cannot give it to his sons!. the mother must be a carrier!.
the girl on top of me is right!. if looking at JUST sons then it is 1/2!. if looking at ALL the children it is 1/4!.Www@Answer-Health@Com
1/4 or 25%
because if one son was able to get it that means that each parent must have had one r gene so that would make it 1/4Www@Answer-Health@Com
because if one son was able to get it that means that each parent must have had one r gene so that would make it 1/4Www@Answer-Health@Com