Question

4. Hitchhiker's thumb (H) is dominant to no hitchhiker's thumb (h). A woman who does not have hitchhiker's thumb marries a man who is heterozygous for hitchhiker's thumb. What is the probable genotypic ratio of their children? (SC.912.L.16.1)

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1 point
0% Hh: 100% hh
50% Hh: 50% hh
75% Hh: 25% hh
100% Hh: 0% hh

Answer 1

To find the probable genotypic ratio of the children, we need to look at the genotypes of the parents.

The woman does not have hitchhiker's thumb, which means her genotype must be homozygous recessive (hh).

The man is heterozygous for hitchhiker's thumb, so his genotype is (Hh).

Now we can set up a Punnett square to visualize the possible genotypes of their children:

```
H h
----------------
h | Hh | hh |
----------------
h | Hh | hh |
----------------
```

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

- 50% (Hh) - heterozygous (with hitchhiker's thumb)
- 50% (hh) - homozygous recessive (without hitchhiker's thumb)

Therefore, the probable genotypic ratio of their children is:

**50% Hh: 50% hh** (Answer choice: 50% Hh: 50% hh)