Characteristic of Angiosperms which distinguish them from gymnosperms

Options

A. (a) presence of fruits and flowers
B. (b) double fertilization and triploid endosperm formed after double fertilization
C. (c) companion cells in phloem and vessels in xylem
D. (d) all of the above.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for characteristics that distinguish angiosperms from gymnosperms. We need to identify features that are present in angiosperms but absent in gymnosperms.

2. **Identifying Key Characteristics**:
- **Presence of Fruits and Flowers**: Angiosperms are known for having flowers and fruits, which are not found in gymnosperms. Gymnosperms reproduce through cones and do not produce flowers or fruits.

- **Double Fertilization**: This is a unique process in angiosperms where one sperm fertilizes the egg to form a zygote, while another sperm fuses with two polar nuclei to form a triploid endosperm. This endosperm serves as a food source for the developing embryo, a feature not seen in gymnosperms.

- **Vessels in Xylem and Companion Cells in Phloem**: Angiosperms have specialized structures like vessels in their xylem for efficient water transport and companion cells in their phloem for enhanced nutrient transport. Gymnosperms lack these specialized structures.

3. **Conclusion**: All the identified characteristics (presence of fruits and flowers, double fertilization, and specialized vascular tissues) are features that distinguish angiosperms from gymnosperms. Therefore, the correct answer is that all of these features are present in angiosperms and absent in gymnosperms.

### Final Answer:
The characteristics of angiosperms that distinguish them from gymnosperms include:
- Presence of fruits and flowers
- Double fertilization and formation of triploid endosperm
- Presence of vessels in xylem and companion cells in phloem

Thus, the answer is **D) All of the above**.