Gymnosperms generally lack :

Options

A. xylem vessels and companion cells in phloem
B. xylem tracheids and sieve tubes in phloem
C. xylem vessels and sieve tubes in phloem
D. xylem tracheids and companion cells in phloem

Explanation

To solve the question "Gymnosperms generally lack:", we will analyze the options provided and determine which components are absent in gymnosperms.

### Step-by-Step Solution:

1. **Understand the Structure of Gymnosperms**:
- Gymnosperms are a group of seed-producing plants that include conifers. They have a specific structure in their xylem and phloem.

2. **Identify Components in Xylem and Phloem**:
- **Xylem**: In gymnosperms, the xylem primarily consists of tracheids (not vessels) and parenchyma.
- **Phloem**: The phloem in gymnosperms contains sieve cells (not sieve tubes) and phloem parenchyma.

3. **Analyze the Options**:
- **Option A**: Xylem vessels and companion cells in phloem.
- **Analysis**: Gymnosperms lack xylem vessels and companion cells. This option is correct.
- **Option B**: Xylem tracheids and sieve tubes in phloem.
- **Analysis**: Gymnosperms have xylem tracheids, and they do not have sieve tubes (they have sieve cells instead). This option is incorrect.
- **Option C**: Xylem vessels and sieve tubes in phloem.
- **Analysis**: Gymnosperms lack xylem vessels, but they do not have sieve tubes (they have sieve cells). This option is incorrect.
- **Option D**: Xylem tracheids and companion cells in phloem.
- **Analysis**: Gymnosperms have xylem tracheids, but they lack companion cells. This option is incorrect.

4. **Conclusion**:
- The correct answer is **Option A**: Gymnosperms generally lack xylem vessels and companion cells in phloem.

### Final Answer:
Gymnosperms generally lack xylem vessels and companion cells in phloem.

---