Question

Having freckles (F) is dominant over not having freckles (f). A parent with freckles is crossed with a parent without freckles. The Punnett square shows the possible genotypes of the offspring.

What is the probability that an offspring will have a homozygous dominant genotype?
0
%

What is the probability that an offspring will have a heterozygous genotype?
%

What is the probability that an offspring will have a homozygous recessive genotype?
%

Answer 1

To determine the probabilities of the offspring's genotypes, let's first establish the genotypes of the parent organisms involved in the cross.

- The parent with freckles can have either a homozygous dominant genotype (FF) or a heterozygous genotype (Ff).
- The parent without freckles must have a homozygous recessive genotype (ff).

Assuming the parent with freckles is heterozygous (Ff), we can set up the Punnett square as follows:

```
F f
----------------------
f | Ff ff
|
f | Ff ff
```

From this Punnett square, we can determine the probabilities of the different genotypes:

1. **Homozygous dominant (FF)**: In this scenario, there are **0** offspring with the homozygous dominant genotype since there is no FF combination in the Punnett square.
- Probability: **0%**

2. **Heterozygous (Ff)**: There are **2** Ff offspring out of a total of **4** (2 Ff and 2 ff).
- Probability: \(\frac{2}{4} \times 100 = 50%\)

3. **Homozygous recessive (ff)**: There are **2** ff offspring out of a total of **4**.
- Probability: \(\frac{2}{4} \times 100 = 50%\)

In summary:

- Probability of homozygous dominant genotype (FF): **0%**
- Probability of heterozygous genotype (Ff): **50%**
- Probability of homozygous recessive genotype (ff): **50%**