Question

Assertion (A): Phloem fibres (bast fibres) are made up of sclerenchymatous cells. 
Reason (R): Phloem fibres are generally absent in primary phloem but found in secondary phloem.

• A. A and R are correct. R is the correct explanation of A
• B. A and R are correct. R is not the correct explanation of A
• C. A is correct but R is incorrect
• D. A is incorrect but R is correct

Hint:

Phloem fibres (bast fibres) are crucial for mechanical support in plants, particularly in secondary growth.

Answer 1

The Correct Option is A

Step 1: Understanding Phloem fibres (bast fibres)
Phloem fibres are sclerenchymatous cells that are thick-walled and lignified, which provide structural support to the plant. These fibres are typically found in the secondary phloem, not in the primary phloem.
Step 2: Evaluating the reasoning
The reasoning correctly explains the assertion because phloem fibres are absent in primary phloem but are present in secondary phloem, where they help in providing mechanical strength to the plant.
Final Answer: \[ A\text{ and }R\text{ are correct. R is the correct explanation of A.} \]