Name the organisms which are made up of single cell.

Options

A. Unicellular organisms
B. Multicellular organisms
C. Both of these
D. None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for organisms that are made up of a single cell.

2. **Identifying the Types of Organisms**: Organisms can be classified into two main categories based on the number of cells they have:
- Unicellular organisms: These are organisms that consist of a single cell.
- Multicellular organisms: These are organisms that are made up of two or more cells.

3. **Identifying Unicellular Organisms**: Examples of unicellular organisms include:
- Bacteria: These are microscopic single-celled organisms that can be found in various environments.
- Protozoa: These are single-celled eukaryotic organisms, such as amoeba and paramecium.
- Algae: Some types of algae, like Chlamydomonas, are unicellular.
- Yeast: This is a type of fungus that is also unicellular.

4. **Conclusion**: The organisms that are made up of a single cell are collectively known as unicellular organisms.

**Final Answer**: Unicellular organisms include bacteria, protozoa, certain algae, and yeast.

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