Question

need your help with this please

In guinea pigs, dark hair (D) is dominant over light hair (d) and curly hair (C) is dominant over smooth hair (c). Complete a dihybrid cross for parents with the genotypes: DdCc × DdCc and answer the following in complete sentences.

Describe how you would set up a Punnett square for this cross.
List the likelihood of each possible offspring genotype.
List the likelihood of each possible offspring phenotype.

Answer 1

is this question too difficult for you guys? ;(

Answer 2

This question is not too difficult.

The first thing you need to do is figure out what possible combinations of alleles each of the two parents can pass on to its offspring. Each parent has two copies of each gene - but it will only pass one of those two copies of each gene on to each particular offspring.

The parents are both DdCc. So if you look at that first D chromosome, it can pair itself with either the C chromosme or the c chromosome. So two of your combinations are DC and Dc. Same goes for the d chromosome - it can be passed on with either C or c. So its possible combinations are dC and dc.

So your four possible combinations for each parent are DC, Dc, dC and dc. Those are what you should put on the sides of the Punnett Square. Hope that is helpful.