The offspring of AA bb `xx` aa BB is crossed with , aabb. The genotypic ratio of progeny will be

Options

A. `9:3:3:1`
B. `1:2:1`
C. `1:1:1:1`
D. `4:1`

Answer

To solve the problem of determining the genotypic ratio of the progeny from the cross between the offspring of AA bb xx aa BB and aabb, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Genotypes of the Parents**:
- The first parent is AA bb (which can be simplified to AABB) and the second parent is aabb.

2. **Determine the Gametes for Each Parent**:
- For the first parent (AA bb), the gametes produced will be:
- Gametes: AB and Ab (since AA can only contribute A and bb can only contribute b).
- For the second parent (aabb), the gametes produced will be:
- Gametes: ab (since aa can only contribute a and bb can only contribute b).

3. **Cross the Gametes**:
- Now, we will cross the gametes from both parents:
- Parent 1 gametes: AB, Ab
- Parent 2 gametes: ab
- The possible combinations of offspring will be:
- AB x ab = AaBb
- Ab x ab = Aabb

4. **List the Offspring Genotypes**:
- From the combinations above, the offspring genotypes are:
- 1 AaBb
- 1 Aabb

5. **Count the Genotypes**:
- The genotypes can be summarized as:
- 1 AaBb
- 1 Aabb
- Therefore, we have a total of 2 different genotypes.

6. **Determine the Genotypic Ratio**:
- The genotypic ratio of the progeny is:
- 1 AaBb : 1 Aabb

### Final Answer:
The genotypic ratio of the progeny will be 1:1.

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