To solve this problem, we need to understand the genetic information given:
- Mom's genotype: Heterozygous for dimples. The allele for dimples is "D" (dominant), and the allele for no dimples is "d" (recessive). A heterozygous genotype would be "Dd".
- Dad's genotype: Homozygous for no dimples, which would be "dd".
With these genotypes in mind, we can construct a Punnett square to predict the possible genotypes of their offspring. A Punnett square is a grid used to show the different ways alleles from each parent can combine.
Here is the step-by-step process:
1. Set up the Punnett square grid: Since each parent provides one allele for the trait, we'll create a 2x2 grid.
2. Label the parent's alleles on the Punnett square:
- For mom (Dd), we place her possible alleles "D" and "d" on the top.
- For dad (dd), we place his alleles "d" and "d" on the side.
3. Fill in the Punnett square:
- Combine each of mom’s alleles with each of dad’s alleles in the grid.
The process would look like this:
[tex]\[ \begin{array}{c|c|c}
& D & d \\
\hline
d & \text{Dd} & \text{dd} \\
\hline
d & \text{Dd} & \text{dd} \\
\hline
\end{array} \][/tex]
So, the completed Punnett square is:
[tex]\[ \begin{array}{c|c|c}
& D & d \\
\hline
d & Dd & dd \\
\hline
d & Dd & dd \\
\hline
\end{array} \][/tex]
This tells us that there are two possible genotypes for the offspring:
- "Dd" (having dimples)
- "dd" (not having dimples)
The Punnett square predicts that the ratio of offspring will be:
- 50% chance (or 2 out of 4) of having the "Dd" genotype (dimples)
- 50% chance (or 2 out of 4) of having the "dd" genotype (no dimples)
