Colchicine results in doubling of chromosome number because of

Options

A. Splitting of chromosomes
B. Non-pairing of chromosomes
C. Double replication of chromosomes
D. Non-formation of spindle

Answer

**Step-by-Step Solution:**

1. **Understanding Colchicine**: Colchicine is a chemical compound that acts as a mitotic poison. It is commonly used in biological research and medicine to study cell division.

2. **Role in Cell Division**: During cell division, specifically in the process of mitosis, spindle fibers are crucial for the proper segregation of chromosomes. These spindle fibers help in pulling the chromosomes apart to opposite poles of the cell.

3. **Effect of Colchicine**: When colchicine is introduced, it inhibits the formation of spindle fibers. This means that the spindle apparatus, which is responsible for separating the chromosomes during metaphase, does not form properly.

4. **Consequences of Spindle Inhibition**: Due to the lack of spindle fibers, the chromosomes do not separate as they normally would. Instead, both sets of chromosomes move towards the same pole of the cell during anaphase.

5. **Resulting Chromosome Doubling**: As a result of this improper segregation, the cell ends up with double the number of chromosomes. Instead of dividing into two cells with a complete set of chromosomes, the cell retains both sets, leading to a doubling of the chromosome number.

6. **Conclusion**: Therefore, the correct answer to the question is that colchicine results in the doubling of chromosome number because of the non-formation of spindle fibers during cell division.

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