Which of the following represents an amphidiploid (or allopolyploid) condition?

Options

A. A plant having a chromosome number which is not an exact multiple of the haploid number
B. A plant derived by doubling the chromosomes of `F_(1)` hybrid of two species
C. A polyploid containing genetically different chromosomes sets derived from two or more species
D. A polyploid species in which the genomes have been derived from the same original species

Answer

To determine which of the options represents an amphidiploid (or allopolyploid) condition, we need to analyze the definitions and characteristics of amphidiploids.

### Step-by-Step Solution:

1. **Understanding Amphidiploids**:
- Amphidiploids, also known as allopolyploids, are organisms that have two sets of chromosomes, each derived from different species. This means they contain diploid sets of chromosomes from two different species.

2. **Analyzing the Options**:
- **Option 1**: A plant having a chromosome number which is not an exact multiple of the haploid number.
- This does not represent an amphidiploid condition because it does not specify the origin of the chromosome sets.

- **Option 2**: A plant derived by the doubling of chromosomes of an F1 hybrid of two species.
- This is a description of how amphidiploids can arise, as the F1 hybrid is typically sterile, and the doubling of its chromosomes can lead to a fertile amphidiploid condition. However, it does not directly define the condition itself.

- **Option 3**: A polyploid containing genetically different chromosome sets derived from two or more species.
- This option accurately describes an amphidiploid condition, as it specifies that the chromosome sets are genetically different and derived from two different species.

- **Option 4**: A polyploid species in which the genomes have been derived from the same original species.
- This describes a homoploid condition, not an amphidiploid condition, as it refers to chromosome sets from the same species.

3. **Conclusion**:
- The correct answer is **Option 3**: A polyploid containing genetically different chromosome sets derived from two or more species, as it best represents the amphidiploid condition.