Many unicellular organisms reproduce by the process of

Options

A. fission
B. regeneration
C. ovulation
D. nondisjuction

Answer

**Step-by-Step Solution:**

1. **Identify the Type of Organisms**: The question refers to unicellular organisms. These include bacteria and protists.

2. **Understand the Reproductive Methods**: Unicellular organisms primarily reproduce asexually. Asexual reproduction does not involve the fusion of gametes and allows for rapid population growth.

3. **Focus on Asexual Reproduction**: The most common method of asexual reproduction in unicellular organisms is fission.

4. **Differentiate Types of Fission**: There are two main types of fission:
- **Binary Fission**: This is when a single organism divides into two identical organisms. An example of this is seen in bacteria.
- **Multiple Fission**: This occurs when a single organism divides into many individuals simultaneously. An example of this is seen in the protozoan Plasmodium.

5. **Evaluate Other Options**:
- **Regeneration**: This is a process where certain organisms can regrow lost parts. It is not a primary method of reproduction for unicellular organisms.
- **Ovulation**: This is related to sexual reproduction, where an egg is released from the ovary. It is not applicable to unicellular organisms.
- **Non-disjunction**: This is a failure of chromosomes to separate properly during cell division, which is not a method of reproduction.

6. **Conclude with the Correct Answer**: Based on the analysis, the correct answer to the question is **fission**.

**Final Answer**: Many unicellular organisms reproduce by the process of **fission**.

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