Which one of the following would represent allotetraploid?

Options

A. AAABB
B. AAAA
C. AABB
D. BBBB

Answer

To determine which option represents an allotetraploid, we need to understand the definitions of autotetraploid and allotetraploid.

### Step-by-Step Solution:

1. **Understanding Chromosome Sets**:
- Allotetraploid organisms have two different sets of chromosomes (genomes) from two different species, while autotetraploid organisms have four sets of chromosomes from the same species.

2. **Analyzing the Options**:
- **Option 1**: Triple A and double B (represented as AAA BB). This indicates a total of 5n chromosomes, which suggests it is a pentaploid, not an allotetraploid.
- **Option 2**: Four sets of the same genome (AAAA). This indicates an autotetraploid because all four sets are from the same species.
- **Option 3**: Two sets of A and two sets of B (AABB). This indicates an allotetraploid because it has two different genomes (A and B).
- **Option 4**: Four sets of the same genome (AAAA). This is again an autotetraploid.

3. **Conclusion**:
- The only option that represents an allotetraploid is **Option 3 (AABB)**, which has two different sets of chromosomes.

### Final Answer:
The correct representation of an allotetraploid is **Option 3 (AABB)**.

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