Phloem of gymnosperms differ from angiosperms in

Options

A. having no companion cells
B. having no sieve cells
C. having phloem fibre
D. having phloem parenchyma

Answer

**Step-by-Step Solution:**

1. **Understanding Phloem**: Phloem is a type of vascular tissue in plants responsible for the transport of nutrients, particularly sugars produced through photosynthesis. It works alongside xylem, which transports water.

2. **Identifying Plant Groups**: There are two main groups of seed-producing plants: gymnosperms and angiosperms. Gymnosperms have naked seeds and do not produce flowers, while angiosperms are flowering plants that produce seeds enclosed within a fruit.

3. **Components of Phloem**: Phloem is composed of several elements, including:
- **Sieve Cells (or Sieve Tube Elements)**: These are the main conducting cells in phloem.
- **Companion Cells**: These are specialized cells that assist sieve tube elements in their function.
- **Phloem Fibers**: These provide structural support.
- **Phloem Parenchyma**: These cells are involved in storage and transport.

4. **Differences in Phloem Structure**: The key difference between the phloem of gymnosperms and angiosperms is the presence of companion cells.
- **Gymnosperms**: They lack companion cells and instead have sieve cells that function independently.
- **Angiosperms**: They have both sieve tube elements and companion cells, which help in maintaining the pressure gradient necessary for the transport of nutrients.

5. **Conclusion**: Therefore, the main difference in the phloem of gymnosperms compared to angiosperms is that gymnosperms do not have companion cells.

**Final Answer**: The phloem of gymnosperms differs from angiosperms in having no companion cells.

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