Identify the giant chromosomes

Options

A. B-chromosomes
B. G-chromosomes
C. Polytene-chromosomes
D. Q-band chromosome

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks to identify giant chromosomes from the given options: B chromosomes, G chromosomes, polytine chromosomes, and cuban chromosomes.

2. **Definition of Giant Chromosomes**: Giant chromosomes are characterized by their large size and the presence of thousands of DNA strands. They are typically found in specific tissues of certain organisms.

3. **Identifying the Location**: Giant chromosomes are most commonly found in the salivary glands of certain insects, particularly in dipteran flies (like fruit flies).

4. **Mechanism of Formation**: These chromosomes are formed through repeated rounds of DNA replication that occur without cell division. This process leads to the formation of multiple sister chromatids that remain fused together, resulting in a large chromosome structure.

5. **Function of Giant Chromosomes**: The presence of giant chromosomes provides metabolic advantages and aids in cell expansion, as they increase the volume of the cell.

6. **Selecting the Correct Option**: Among the options provided, polytine chromosomes are specifically known as giant chromosomes due to their characteristics and formation process.

7. **Conclusion**: Therefore, the correct answer to the question is **polytine chromosomes**.

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