Two genes 'A' and 'B' are linked. In a dihybrid cross involving these two genes, the `F_(1)` heterozyogte is crossed with homozygous recessive parental type (aa bb). What would be the ratio of offspring in the next generation?

Options

A. `1:1:1:1`
B. `9:3:3:1`
C. `3:1`
D. `1:1`

Explanation

To solve the problem of the dihybrid cross involving two linked genes 'A' and 'B', we will follow these steps:

### Step 1: Identify the Genotypes
We have two genes, A and B, which are linked. The F1 heterozygote will have the genotype AaBb, and we are crossing this with a homozygous recessive parent, which has the genotype aabb.

### Step 2: Determine the Gametes
Since the genes are linked, the gametes produced by the F1 heterozygote (AaBb) will be:
- AB (dominant for both traits)
- ab (recessive for both traits)

The homozygous recessive parent (aabb) can only produce one type of gamete:
- ab

### Step 3: Set Up the Cross
Now we set up the cross between the gametes from the F1 heterozygote and the homozygous recessive parent:
- From AaBb (F1): AB, ab
- From aabb (parent): ab

The possible combinations of gametes will be:
1. AB (from AaBb) and ab (from aabb) → AaBb
2. ab (from AaBb) and ab (from aabb) → aabb

### Step 4: Count the Offspring Genotypes
From the combinations above, we can see that the offspring will be:
- 1 AaBb
- 1 aabb

### Step 5: Determine the Ratio
The ratio of the offspring genotypes is:
- 1 AaBb : 1 aabb

This can be simplified to:
- 1 : 1

### Final Answer
The ratio of offspring in the next generation is **1:1**.

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