You are given an unknown plants to study in the laboratory. You find that it has chlorophyll, no xylem. Its multicellular sex organs are enclosed in a layer of jacket cells. Its gametophyte stage is free living. The plant probably belongs to-

Options

A. Chlorophyceae
B. Bryophyte
C. Pteridophyte
D. Gymnosperm

Answer

To determine the classification of the unknown plant based on the provided characteristics, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics of the Plant**:
- The plant has chlorophyll, indicating it is photosynthetic.
- It lacks xylem, which means it does not have the vascular tissue typically found in higher plants.
- The sex organs are multicellular and enclosed in a layer of jacket cells.
- The gametophyte stage is free-living.

2. **Analyze the Characteristics**:
- **Chlorophyll**: This suggests that the plant is capable of photosynthesis, which is common in several plant groups.
- **No Xylem**: The absence of xylem indicates that the plant is likely non-vascular. This rules out higher plants such as pteridophytes (ferns) and gymnosperms (conifers), which possess xylem.
- **Multicellular Sex Organs**: The presence of multicellular sex organs that are jacketed is a characteristic feature of certain groups of plants.
- **Free-Living Gametophyte**: This is a significant characteristic, as it suggests that the dominant phase of the plant's life cycle is the gametophyte, which is typical of bryophytes.

3. **Compare with Plant Groups**:
- **Chlorophyceae (Green Algae)**: While they have chlorophyll, their sex organs are not multicellular, so this group can be excluded.
- **Bryophytes**: They are characterized by having multicellular sex organs, a dominant gametophyte stage, and they are non-vascular (no xylem). This matches all the characteristics of the unknown plant.
- **Pteridophytes**: These plants have vascular tissues (xylem and phloem), so they can be excluded.
- **Gymnosperms**: Similar to pteridophytes, they possess vascular tissues and can also be excluded.

4. **Conclusion**:
Based on the analysis, the unknown plant most likely belongs to the group of **Bryophytes**.

### Final Answer:
The plant probably belongs to **Bryophytes**.

---