Question

In guinea pigs, short hair, S, is dominant to long hair, s.

Two heterozygous short hair guinea pigs mate. Write the genotype ratio

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Answer 1

In this genetic scenario, we have two heterozygous short-haired guinea pigs, which means their genotypes are both Ss (where S represents the dominant short hair allele and s represents the recessive long hair allele).

To determine the genotype ratio, we can use a Punnett square to visualize the possible offspring genotypes from this cross.

Here’s the Punnett square for the cross:

```
S s
----------------
S | SS | Ss |
----------------
s | Ss | ss |
----------------
```

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

- **SS**: 1 occurrence
- **Ss**: 2 occurrences
- **ss**: 1 occurrence

Now, the genotypes of the offspring are:

- 1 SS (homozygous dominant)
- 2 Ss (heterozygous)
- 1 ss (homozygous recessive)

Therefore, the genotype ratio is:

**1 SS : 2 Ss : 1 ss**