Biology Question

[Dencology]

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Hey, i am having a hard time with understanding the Autosomal Recessive concept and problems involving this topic.

 

[LAWL]

can you be bit more specific so I can tailor your question a bit more ?

 

[Dencology]

well, there is a question in Destroyer #228. Moreover, i thought that there is a 50% chance of having the disease for children if both parents are autosomal recessive of a disease!!! thanks for replying

 

[Streetwolf]

Without the actual question I can't really help you out, but I will say this. If both parents are autosomal recessive for a gene (call the gene B where B = dominant and b = recessive) then 100% of their kids will be autosomal recessive. Make a Punnett Square.

If both parents have bb (so bb x bb) then the only option for the children is bb.

 

[PreDent2009]

Since both parents are carriers, that means each child they have will have a 25% chance of carrying the gene. Since only 1 out of every 50 people are completely recessive, that means only 2% of the population has the gene. Since each parents holds the trait, they represent .02. So the probability of having a diseased child is .25 X .02 X .02, which is somewhere around .01 percent.