Who coined the term 'heterozygous'?

Options

A. Bateson
B. Saunders
C. Jahannsen
D. All except (3)

Answer

To answer the question "Who coined the term 'heterozygous'?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Term**: The term we are looking for is "heterozygous". This term is used in genetics to describe an organism that has two different alleles for a particular gene.

2. **Research the Origin**: The term "heterozygous" was coined by biologists in the early 20th century. It is important to find out who specifically introduced this term.

3. **Key Figures**: The key figures associated with the term "heterozygous" are William Bateson and Edith Rebecca Saunders. They were both English biologists.

4. **Publication Context**: Bateson and Saunders introduced the term in a paper published in 1902. The title of the paper was "The Facts of Heredity in the Light of Mendel's Discovery". This indicates that their work was influenced by Gregor Mendel's earlier research on inheritance.

5. **Conclusion**: Therefore, the term "heterozygous" was coined by William Bateson and Edith Rebecca Saunders in 1902.

6. **Final Answer**: The correct answer to the question is that the term "heterozygous" was coined by William Bateson and Edith Rebecca Saunders, making the answer option "all except three" since they are both credited with the term.