Select true statements -
(A) Bast fibres are made up of sclerenchymatous cells.
(B) The companion cells help in maintaining the pressure gradient in the sieve tubes.
(C) Phloem parenchyma is absent in Zea mays stem

Options

A. Only A and B
B. Only B & C
C. Only C
D. All A, B, and C

Answer

To determine which statements are true, we will analyze each statement one by one.

**Step 1: Analyze Statement A**
- Statement A claims that "Bast fibres are made up of sclerenchymatous cells."
- Bast fibers, also known as phloem fibers, are indeed composed of sclerenchymatous cells. These cells provide strength and support to the plant.
- **Conclusion**: Statement A is true.

**Step 2: Analyze Statement B**
- Statement B states that "The companion cells help in maintaining the pressure gradient in the sieve tubes."
- Companion cells are closely associated with sieve tubes in the phloem. They play a crucial role in maintaining the pressure gradient necessary for the transport of nutrients through the sieve tubes, especially since sieve tubes lack a nucleus.
- **Conclusion**: Statement B is true.

**Step 3: Analyze Statement C**
- Statement C claims that "Phloem parenchyma is absent in Zea mays stem."
- Zea mays (corn) is a monocot plant. In monocots, phloem parenchyma is typically absent. Therefore, this statement is accurate.
- **Conclusion**: Statement C is true.

**Final Conclusion:**
- All three statements (A, B, and C) are true.

**Final Answer**: All statements A, B, and C are true.

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