Colchicine results in doubling of chromosome number because of

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding Colchicine**: Colchicine is a toxic compound that is known to inhibit mitosis in cells. It is important to recognize its role in the cell cycle.

2. **Mechanism of Action**: Colchicine works by preventing the polymerization of microtubules. Microtubules are essential components of the spindle fibers that are responsible for separating chromosomes during cell division.

3. **Impact on Spindle Fiber Formation**: Since colchicine inhibits the polymerization of microtubules, it leads to the non-formation of spindle fibers. Without spindle fibers, the cell cannot properly segregate its chromosomes during mitosis.

4. **Consequences of Non-formation of Spindle Fibers**: In the metaphase stage of mitosis, chromosomes align at the metaphase plate. If spindle fibers are not formed, the chromosomes cannot be pulled apart and segregated into two daughter cells.

5. **Resulting Effect on Chromosome Number**: Because the chromosomes do not segregate properly, they remain together in the same cell. This results in a doubling of the chromosome number in the daughter cells, as they end up with both sets of chromosomes instead of one.

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

**Final Answer**: Colchicine results in doubling of chromosome number because of the non-formation of spindle fibers.

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