Double fertilization is a characteristic of

Options

A. Angiosperms
B. Pteriodophytes
C. Gymnosperms
D. Bryophytes.

Answer

### Step-by-Step Solution:

1. **Understanding Double Fertilization**:
- Double fertilization is a unique reproductive process where two sperm cells (male gametes) from a pollen grain fertilize two different structures in the ovule of a flowering plant.

2. **Identifying the Organisms**:
- This process is specifically characteristic of flowering plants, which are scientifically known as angiosperms.

3. **Process of Double Fertilization**:
- When pollen lands on the stigma of a flower, it germinates and forms a pollen tube that grows down into the ovule.
- The pollen tube releases two sperm cells into the ovule.
- One sperm cell fuses with the egg cell, resulting in the formation of the zygote (this is the first fertilization).
- The second sperm cell fuses with the two polar nuclei in the ovule, forming the triploid endosperm (this is known as triple fusion).

4. **Conclusion**:
- Since double fertilization involves the fusion of two male gametes with different structures, it is a defining characteristic of angiosperms.

### Final Answer:
Double fertilization is a characteristic of **angiosperms** (flowering plants).