Duchene muscular dystrophy is sex linked and recessive. The children appear normal for several years and then the muscles start to progressively degenerate until the person is crippled. Death usually occurs in the early 20's. When Ms. Ridenour lived in Laos many years ago, the Royal Lao family in the province had 8 children. The daughter was normal, but 6 sons were beridden with muscular dystrophy. The last son was then about 8 years old and appeared to be healthy. What is the probability that he would be a normal male when he grew up? I think it's 0%. What are the genotypes of the following? Mother= Father= Afflicted sons= (I think this is 100%) Thanks ahead of time! So, I made a punnet square and I wanted to know what goes on top and the sides. If you could also state that I would greatly appreciate it. ALSO, (really sorry) is the male dominant or recessive? vballan...I don't get your answer...Sorry, could you be more clear?
Biology - 2 Answers
Random Answers, Critics, Comments, Opinions :
1 :
If its sex-linked recessive its carried on the males Y chromosome and 100% of male offsrping will be afflicted.
2 :
Mother is Xd X Father is XY We know this because the parents lived to have children with no apparent effects (it doesn't say how old the parents were, but I assume they weren't teenagers). I mispoke about the 100% before b/c I misread the question. Here's the right answer.... XX are girls, XY are boys. Xd denotes the disease allele which is lowercase because it's recessive (X and Y are normal). Mom---> Xd X (mom is a carrier since she doesn't show the disease, but her sons have it) Dad ---> X Y (dad has to be normal since he doesn't have the disease) Punnett square: Xd X X XdX XX Y XdY XY Her daughters have a 50% chance of carrying the trait and 50% chance of being normal. Her sons have a 50% chance of having the disease (XY males only need one copy to show the trait) and 50% of being normal. We know the mom is a carrier since at least some of her sons have the trait. If she was normal, her previous sons wouldn't have the trait. If she was XdXd, she would have the trait.
Read more discussions :
