Assertion : Translocation of sugar from source to sink is defined as pressure flow hypothesis. Reason : Translocations of the solutes is facilitated through living phloem sieve tube cells

Options

A. If both are true with reason being correct explanation (A).
B. both true but reason is not correct explanation (B),
C. Assertion true but reason is wrong (C),
D. both are wrong (D),

Answer

To solve the question regarding the assertion and reason about the translocation of sugar in plants, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Translocation of sugar from source to sink is defined as pressure flow hypothesis."
- The pressure flow hypothesis explains how sugars (mainly sucrose) are transported from the source (where they are produced, like leaves) to the sink (where they are used or stored, like roots or fruits) through the phloem.

2. **Evaluating the Reason**:
- The reason states that "Translocation of the solutes is facilitated through living phloem sieve tube cells."
- This is indeed true as the phloem consists of living cells, specifically sieve tube elements, which are essential for the transport of solutes.

3. **Analyzing the Relationship**:
- While both the assertion and reason are true, the reason does not directly explain the assertion. The assertion focuses on the mechanism (pressure flow hypothesis) while the reason describes the nature of the cells involved in the process.

4. **Conclusion**:
- Since both statements are true but the reason does not serve as a correct explanation for the assertion, the correct answer is that both are true, but the reason is not the correct explanation.

### Final Answer:
- The correct option is **B**: Both are true, but the reason is not the correct explanation.