In salivary gland chromosomes/polytene chromosomes, pairing is

Options

A. absent
B. occasional
C. formed between non-homologous chromosomes
D. formed between homologous chromosomes

Explanation

### Step-by-Step Solution:

1. **Understanding Polytene Chromosomes**:
- Polytene chromosomes are large chromosomes that are formed by the replication of DNA without cell division. They are primarily found in the salivary glands of certain organisms, such as Drosophila (fruit flies).

2. **Location of Polytene Chromosomes**:
- These chromosomes are specifically located in the nuclei of the salivary glands of the larvae of Drosophila during the interphase stage of the cell cycle.

3. **Nature of Pairing**:
- In polytene chromosomes, there is a phenomenon known as somatic pairing. This refers to the alignment and pairing of homologous chromosomes.

4. **Homologous Chromosomes**:
- Homologous chromosomes are pairs of chromosomes that have the same structure and carry genes for the same traits, although they may have different alleles.

5. **Conclusion**:
- In salivary gland chromosomes (polytene chromosomes), the pairing occurs between homologous chromosomes. Therefore, the correct answer to the question is that pairing is formed between homologous chromosomes.

### Final Answer:
In salivary gland chromosomes (polytene chromosomes), pairing is formed between homologous chromosomes.

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