Hexaploid or modern wheat developed through

Options

A. Hybridomas
B. Chromosome doubling
C. Hybridisation
D. Hybridisation and chromosome doubling

Answer

### Step-by-Step Solution:

1. **Understanding Hexaploid Wheat**:
- Hexaploid wheat, also known as modern wheat, has a chromosome number represented as 6N, meaning it has six sets of chromosomes.

2. **Origin of Hexaploid Wheat**:
- The development of hexaploid wheat involved the crossing of two diploid wild varieties of wheat. This hybridization was essential to introduce superior traits from both parent varieties.

3. **Formation of Tetraploid Wheat**:
- The initial crossing of the two diploid varieties resulted in a tetraploid wheat variety (4N), which contains four sets of chromosomes. This step is crucial as it lays the foundation for the next stage of development.

4. **Chromosome Doubling**:
- To achieve the hexaploid state, the tetraploid wheat underwent chromosome doubling. This means that the chromosome number was increased from 4N to 6N, leading to the formation of hexaploid wheat.

5. **Final Conclusion**:
- The process that led to the development of hexaploid or modern wheat is a combination of hybridization and chromosome doubling. Therefore, the correct answer to the question is "hybridization and chromosome doubling."

### Final Answer:
**The correct answer is option 4: Hybridization and chromosome doubling.**

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