Question

Cross a male fruit fly with vestigial wing type and a female fruit fly with wild type using Punnett Square

Answer 1

To set up a Punnett Square for the cross between a male fruit fly with vestigial wings and a female with wild-type wings, we first need to establish the genotypes of the parents based on the traits we are interested in.

In fruit flies (Drosophila melanogaster):
- The allele for wild-type wings (normal wings) is typically denoted as **V** (dominant).
- The allele for vestigial wings is denoted as **v** (recessive).

**Parental Genotypes:**
- Male (vestigial wings): **vv**
- Female (wild-type wings): **Vv** (this female could be homozygous wild-type **VV**, but since we're looking for wild-type and we know the male has vestigial wings, we can assume the female is heterozygous for this example.)

### Steps to Set Up the Punnett Square:

1. Identify the gametes produced by each parent.
- Male (vv) can only produce **v** gametes.
- Female (Vv) can produce **V** and **v** gametes.

2. Create a 2x2 Punnett Square:

```
V v
----------------
v | Vv | vv
----------------
v | Vv | vv
----------------
```

### Results of the Punnett Square:

- **Genotypes of the offspring**:
- **Vv** (wild-type wings): 2 squares
- **vv** (vestigial wings): 2 squares

### Ratios and Phenotypes:

- **Ratio of genotypes**:
- 2 **Vv** : 2 **vv** or simplified, 1 **Vv** : 1 **vv**

- **Phenotypes**:
- 2 wild-type wings (Vv)
- 2 vestigial wings (vv)

**Phenotypic ratio**:
- 1 wild-type wing : 1 vestigial wing

So, when crossing a male fruit fly with vestigial wings and a female fruit fly with wild-type wings, you would expect half of the offspring to have wild-type wings and half to have vestigial wings.