Who coined the term 'heterosis'

Options

A. Shull
B. Huxley
C. Robard
D. Tansley

Explanation

### Step-by-Step Solution:

1. **Understanding Heterosis**:
- Heterosis, also known as hybrid vigor, refers to the phenomenon where hybrid offspring exhibit superior qualities compared to their parents. This can include increased growth rates, higher fertility, and improved resistance to diseases.

2. **Identifying the Scientist**:
- The question asks who coined the term 'heterosis'. To answer this, we need to look at the options provided: Shell, Huxley, Robot, and Tansley.

3. **Evaluating the Options**:
- **Shell**: This scientist is credited with coining the term 'heterosis' in 1952.
- **Huxley**: Known for coining the term 'new systematics' and is recognized as the father of new systematics.
- **Robot**: This name does not correspond to a known figure in this context.
- **Tansley**: An ecologist who coined the term 'ecosystem'.

4. **Conclusion**:
- Based on the information, the correct answer to the question "Who coined the term 'heterosis'?" is Shell.

### Final Answer:
The term 'heterosis' was coined by Shell in 1952.

---