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 refers to the process by which an embryo forms and develops from a fertilized egg. This process is crucial in the life cycle of plants.

2. **Identifying the Options**: The question provides several options regarding where embryo development occurs. We need to analyze each option to determine the correct answer.

3. **Analyzing Option 1 - All Archegoniaths**: Archegoniaths are structures found in mosses that produce eggs. However, embryo development does not occur in these structures. Therefore, this option is incorrect.

4. **Analyzing Option 2 - Spermatophytes Only**: Spermatophytes are seed-producing plants. While they do undergo embryo development, stating "only" excludes other groups that also exhibit embryo development. Thus, this option is also incorrect.

5. **Analyzing Option 3 - All Vascular Plants and Some Avascular Plants**: Vascular plants, such as pteridophytes (ferns) and spermatophytes (seed plants), do exhibit embryo development. Avascular plants, like bryophytes (mosses and liverworts), also show embryo development. Hence, this option is correct.

6. **Analyzing Option 4 - Vascular Plants Only**: This option suggests that embryo development occurs solely in vascular plants, which is not true since avascular plants also show embryo development. Therefore, this option is incorrect.

7. **Conclusion**: The correct answer is that embryo development is present in all vascular plants and some avascular plants, making option 3 the right choice.

**Final Answer**: Embryo development is present in all vascular plants and some avascular plants.

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