Question

In humans, dimples are a dominant trait. If two parents are both heterozygous for dimples, what percent of their children will also be heterozygous? (1 point)

00%

25%

50%

75%

100%

Answer 1

To determine the percentage of children that will be heterozygous for dimples when both parents are heterozygous, we can use a Punnett square.

Let "D" represent the allele for dimples (dominant) and "d" represent the allele for no dimples (recessive). Since both parents are heterozygous, their genotypes are "Dd".

Here’s how the Punnett square would look:

```
D d
-------------
D | DD | Dd |
-------------
d | Dd | dd |
-------------
```

From the Punnett square, we can see the genotypes of the potential offspring:

- 1 DD (homozygous dominant)
- 2 Dd (heterozygous)
- 1 dd (homozygous recessive)

This results in a total of 4 possible phenotypes:

- 1 DD
- 2 Dd
- 1 dd

To find the percentage of children that are heterozygous (Dd), we take the number of Dd offspring (2) and divide it by the total number of offspring (4):

\[
\text{Percentage of heterozygous offspring (Dd)} = \frac{2}{4} \times 100\% = 50\%
\]

Thus, the answer is **50%**.