Female sex organ of algae is called :-

Options

A. Carpel
B. Oogonium
C. Archegonia
D. Oosphere

Answer

To determine the female sex organ of algae, we need to analyze the options provided in the question:

1. **Carpal**: This is the female reproductive part found in angiosperms (flowering plants), which consists of the stigma, style, and ovary. Therefore, this option is not correct for algae.

2. **Oogonium**: This is a unicellular female sex organ found in algae. It is diploid and produces female gametes. This option is a strong candidate for the correct answer.

3. **Archegonia**: This is a multicellular, flask-shaped female reproductive organ found in bryophytes (like mosses), pteridophytes (like ferns), and gymnosperms (like conifers). This option is not applicable to algae.

4. **Oosphere**: This is the female reproductive cell produced in the oogonium and is fertilized to form a zygote. While it is related to the reproductive process, it is not the female sex organ itself.

Based on this analysis, the correct answer is:

**Oogonium** (Option 2) is the female sex organ of algae.

### Step-by-Step Solution:
1. **Identify the options**: The question provides four options related to female sex organs.
2. **Analyze each option**:
- **Carpal**: Not applicable to algae; it's for angiosperms.
- **Oogonium**: Correct; it's the female sex organ in algae.
- **Archegonia**: Not applicable; it's found in bryophytes, pteridophytes, and gymnosperms.
- **Oosphere**: Related to reproduction but not the organ itself.
3. **Select the correct answer**: After analyzing, we conclude that the female sex organ of algae is the **Oogonium**.