Clone is

Options

A. Descendants of a single parent
B. Vegetatively produced descendants of a single parent
C. Sexually produced descendants of a single couple
D. All the above

Answer

To answer the question "Clone is:", we will analyze the options provided and determine the correct definition of a clone.

### Step-by-Step Solution:

1. **Understanding the Definition of a Clone**:
- A clone refers to an organism or a group of organisms that are genetically identical to the parent organism. This typically occurs without sexual reproduction.

2. **Analyzing the Options**:
- **Option A**: Descendants of a single parent.
- This could be true for asexual reproduction but does not specify the method of reproduction.
- **Option B**: Vegetatively produced descendants of a single parent.
- This specifically refers to a form of asexual reproduction where new individuals are produced from the vegetative parts of the parent (like roots, stems, or leaves).
- **Option C**: Sexually produced descendants of a single couple.
- This involves the fusion of gametes and results in genetic variation, which does not align with the concept of cloning.
- **Option D**: All of the above.
- This option cannot be correct since not all definitions align with the concept of cloning.

3. **Identifying the Correct Answer**:
- Based on the analysis, the most accurate definition of a clone is found in **Option B**: "Vegetatively produced descendants of a single parent." This is because clones arise from asexual reproduction methods, specifically vegetative propagation, leading to genetically identical offspring.

4. **Conclusion**:
- Therefore, the correct answer to the question "Clone is:" is **Option B**.

### Final Answer:
**Option B: Vegetatively produced descendants of a single parent.**

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