Let’s use symbols for better understanding.
It is given that the mother has two alleles, one with and one without. Making the symboled be...Dd.
The father isn’t given so it would be a little hard to add them in a punnet square.
It would depend if the father would have all alleles be recessive (dd), dominant (DD), or be like the mother heterozygous (Dd).
Given the fact that the father isn’t given, here are all the probabilities with all three factors:
1. dd
This would make the result be
(Dd, dd, Dd, dd)
Meaning that there is a 50/50 chance for the offspring to have dimples. The other problem is that the problem doesn’t state that dimples are either dominant nor recessive so, in this case, I’ll assume their recessive.
The other 50% is for the offspring to have heterozygous genes. Meaning that they have the dimples gene but it’s covered up by the dominant gene of not having any.
2. DD
Here it would be really hard to have the offspring to have dimples. The parent has both alleles to be dominant, meaning that they will overrule the gene for dimples. Making the result be...
(DD, DD, Dd, Dd)
There is a 100% chance of the offspring to have the dominant gene overrule the recessive gene. But there is another 50% chance for the offspring to have the recessive gene hidden.
3. Dd
Result is...
(DD, Dd, Dd, dd)
This means that there is a 75% chance for the offspring to have the dominant gene overrule the recessive. But there is a 50% chance for the recessive gene to be hidden. There is a 25% chance for the offspring to have a pure dominant set of alleles, making them not have the recessive gene of having dimples at all. But there is another pure set of alleles for having the recessive gene stand out, a 25% chance for this case.
Hope this helps!
