Embryo development is present in

Options

A. All archegoniates
B. Spermatophytes only
C. All vascular plants and some avascular plants
D. Vascular plants only

Answer

**Step-by-Step Solution:**

1. **Understanding Embryo Development**:
- Embryo development, also known as embryogenesis, refers to the process through which a plant or animal embryo develops from a fertilized egg. In plants, this process results in the formation of a multicellular structure made up of undifferentiated cells.

2. **Analyzing the Options**:
- The question provides four options regarding where embryo development is present:
- **Option 1**: All Archegoniates
- **Option 2**: Spermatophytes only
- **Option 3**: All vascular and some avascular plants
- **Option 4**: Vascular plants only

3. **Evaluating Each Option**:
- **Option 1 (All Archegoniates)**: Archegoniates are structures found in mosses that produce eggs. While they are involved in reproduction, they do not encompass all forms of embryo development.
- **Option 2 (Spermatophytes only)**: Spermatophytes, or seed-producing plants, do involve embryo development, but this option excludes other groups that also undergo this process.
- **Option 3 (All vascular and some avascular plants)**: Vascular plants (like pteridophytes) and some avascular plants (like bryophytes) both exhibit embryo development. This option is inclusive of both groups.
- **Option 4 (Vascular plants only)**: This option excludes avascular plants, which also undergo embryo development.

4. **Conclusion**:
- The correct answer is **Option 3: All vascular and some avascular plants**, as embryo development occurs in both vascular plants (like pteridophytes) and some avascular plants (like bryophytes).