At maturity the sieve plates become impregnated with

Options

A. Cellulose
B. Suberin
C. Callose
D. Lignin

Answer

**Step-by-Step Solution:**

1. **Understanding Sieve Plates**: Sieve plates are structures found in the phloem of flowering plants. They are formed by the end walls of neighboring sieve elements, which are specialized cells that facilitate the transport of nutrients.

2. **Components of Sieve Plates**: Sieve plates are composed of various substances, and at maturity, they undergo changes that involve the impregnation with specific materials.

3. **Options Analysis**: The question provides four options regarding what sieve plates become impregnated with at maturity:
- a) Cellulose
- b) Suberin
- c) Callose
- d) Lignin

4. **Identifying the Correct Substance**: Among the options, callose is known to be a polysaccharide that is deposited in the sieve plates, especially during the maturation of the sieve elements. It helps in the formation and maintenance of the sieve plate structure.

5. **Conclusion**: Therefore, at maturity, sieve plates become impregnated with callose. The correct answer is option (c) callose.

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