Callose can occur in

Options

A. phloem paranchyma
B. campanion cells
C. sieve tubes
D. tracheids

Answer

### Step-by-Step Solution:

1. **Understanding Callose**: Callose is a polysaccharide that plays a crucial role in plant defense mechanisms, particularly in response to stress. It is primarily involved in sealing off damaged areas in plant tissues.

2. **Identifying the Function of Callose**: When a plant experiences stress, such as injury or unfavorable environmental conditions, it responds by depositing callose to create a physical barrier. This barrier helps to isolate the affected tissue and prevent the spread of damage.

3. **Location of Callose Deposition**: Callose is specifically deposited in the sieve plates of the phloem. Sieve plates are structures that facilitate the transport of nutrients in the plant. When stress occurs, callose seals the pores in these sieve plates, thereby protecting the plant's vascular system.

4. **Exclusion of Other Plant Structures**: Callose is not found in other types of plant cells such as phloem parenchyma, companion cells, or tracheids. Its primary location is in the sieve tubes, where it serves its protective function.

5. **Conclusion**: Based on the above information, we conclude that callose can occur in sieve tubes, making it the correct answer.

### Final Answer:
Callose can occur in **sieve tubes**.

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