In Humans, Cystic Fibrosis Is Caused by a Recessive Gene That Is Not Sex-Linked. ……?
A question asked by teshiunata: In humans, cystic fibrosis is caused by a recessive gene that is not sex-linked. ……?
In humans, cystic fibrosis is caused by a recessive gene that is not sex-linked. A man and a woman, neither of whom has cystic fibrosis, have two children with the disease. What is the probability that their third child will have the disease?
Selected answer:
Answer by zini
1 in 4
CF is a recessive gene, the baby needs to get a copy of the gene from both mum and dad before it gets it. The previous children have no impact on future pregnancies.
Do you know better? Why not leave your own answer in the comments below!
Tagged with: ...... • caused • cystic • fibrosis • gene • humans • Recessive • sexlinked.
Filed under: Cystic Fibrosis
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If each parent is a carrier, there is a 1/4 or 25% chance that their offspring will have the disease. You have to have both the recessive genes to show the trait, 50% of their children will be carriers and the other 25% wouldn’t have the gene at all.
CF isn’t an autoimmune disease
If N is the same thing as normal, and c is the gene that represents cystic fibrosis and each parents gives one of each gene, there are 4 possibilities.
Nc x Nc = NN, cN, cN, cc
That’s the equation
So each time they have a child, the probability is all the same. If this world was statistically perfet, and they had 4 children, one would have the disease, 2 would be carriers (and not be sick), and 1 would not even be a carrier.
Id say 25 to 50 percent. Not sure about the probability equation. Although, id lean towards 1 in 4, since CF affects 25,000 newborns a year. The grandparents don’t have a direct influence on the offspring’s, but they give the parents the genes, so they play a major role in the acquisition of CF. That’s why CF is coined a genetic autoimmune disease. See a genetic consular.
idk because i am not smart at human science
My son has CF and Zini is right, previous children have no impact on future pregnancies. It will be a 25% chance with every child.
The best way I found to explain it is you don’t have the same sperm and egg every time you concieve or try to. It is a completely new “pool” of genetics.