Reproduction by autospores occurs in

Options

A. Volvox
B. Ulva
C. Spirogyra
D. Chlorella.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about which organism reproduces by autospores. Autospores are a type of non-motile spore formed within the parent cell.

2. **Defining Autospores**: Autospores are produced inside the parent cell, and they are a form of asexual reproduction. They are also sometimes referred to as apulinospore.

3. **Identifying the Options**: The options given are:
- Volvox
- Ulva
- Spirogyra
- Chlorella

4. **Analyzing Each Option**:
- **Volvox**: This organism reproduces both sexually and asexually, but it does not primarily reproduce by autospores.
- **Ulva**: This is a type of green algae that reproduces through different methods, including fragmentation and sexual reproduction, not specifically by autospores.
- **Spirogyra**: This organism primarily reproduces through conjugation, which is a sexual reproduction method, not by autospores.
- **Chlorella**: This is a unicellular green algae that reproduces asexually by the formation of autospores within the parent cell.

5. **Conclusion**: Based on the analysis, the organism that reproduces by autospores is **Chlorella**.

### Final Answer:
Reproduction by autospores occurs in **Chlorella**.

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