Functional megaspore in an angiosperm develops into

Options

A. ovule
B. endosperm
C. embryo sac
D. embryo

Answer

To answer the question "Functional megaspore in an angiosperm develops into," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Megasporocyte**: In angiosperms (flowering plants), the megasporocyte (or megasporangium) undergoes meiosis to produce four megaspores.

2. **Identifying the Functional Megaspore**: Out of the four megaspores produced, typically only one survives and is referred to as the functional megaspore. The other three megaspores degenerate.

3. **Development of the Functional Megaspore**: The functional megaspore undergoes a process called megagametogenesis. This process involves mitotic divisions of the functional megaspore to form the female gametophyte.

4. **Formation of the Embryo Sac**: The result of megagametogenesis is the formation of the embryo sac, which is the female gametophyte in angiosperms. The embryo sac contains the egg cell and other cells necessary for fertilization.

5. **Fertilization Process**: Upon fertilization, the egg cell within the embryo sac fuses with a male gamete to form the zygote, which eventually develops into the embryo.

6. **Conclusion**: Therefore, the functional megaspore in an angiosperm develops into the embryo sac, which is crucial for the reproductive process.

### Final Answer:
The functional megaspore in an angiosperm develops into the **embryo sac**.

---