Dihybrid Cross Example - Genetics

[christina.n]

I was reviewing my homework, and I came across this problem that I’m not sure how to solve:
A drug, phenyl thoicarbamide (PTC), can be tasted by about 680 out of every 1000 people; others cannot taste it at all. Those who can taste it are called tasters. Those who cannot taste the drug are said to be taste-blind. Tasters have a dominant gene for the trait whereas those who cannot taste the drug have a recessive gene. An albino man who is a taster and has a taste-blind mother, marries a normally pigmented taste-blind woman whose father is an albino taster. What types of children might this couple expect?

Also, could you explain the importance of knowing what traits the parents have? How do parents pass down traits to their children?

[perlaalvarez431]

The importance of knowing what traits the parents have is because the traits that parents have are the only traits the children can have. If the parent’s traits are purely dominant, so AA and AA, than there is no combination of these passed down genes that will produce a child with the recessive trait.
Parents pass down these traits in the chromosomes in their gametes.
For this problem you would have to combine the genes, most likely using a punnett square to determine all the possible combinations of the parents alleles to determine the possible traits of children.

[christina.n]

Hello! Thank you so much for your response When I tried to do the problem, I did a punnett square between bbTt (the albino taster man) and Bbtt (the normally pigmented woman). For my answer, I got albino taste-blind, normal-pigmented taster, normal-pigmented taste-blind, and albino taster, but I’m not sure how to figure out the genotype of the man and woman?