Organisms that are made up of many cells are called multi-cellular organisms, whereas organisms that are made up of only a single cell that performs all functions are called unicellular organisms. Which of the following organisms is unicellular?

Options

A. Pine
B. Algae
C. Sundew
D. Amoebae

Answer

**Step-by-Step Solution:**

1. **Understanding the Definitions**:
- First, we need to understand the definitions of multicellular and unicellular organisms. Multicellular organisms are made up of many cells, while unicellular organisms consist of only a single cell that performs all necessary functions.

2. **Identifying the Organisms**:
- We are given four options: pine, algae, sundew, and amoeba. We need to analyze each one to determine whether it is unicellular or multicellular.

3. **Analyzing the First Option (Pine)**:
- Pine is a type of tree that belongs to the gymnosperm group. Gymnosperms are part of the plant kingdom, which is made up of multicellular organisms. Therefore, pine is multicellular.

4. **Analyzing the Second Option (Algae)**:
- Algae are often classified under the group called thalophyta and are also part of the plant kingdom. While some algae can be unicellular, many are multicellular. However, for the purpose of this question, we consider algae as multicellular.

5. **Analyzing the Third Option (Sundew)**:
- Sundew is a type of plant that is also part of the plant kingdom. Like pine and algae, sundew is a multicellular organism.

6. **Analyzing the Fourth Option (Amoeba)**:
- Amoeba belongs to the kingdom Protista and is classified as a protozoan. Protozoans are known to be unicellular organisms. Therefore, amoeba is unicellular.

7. **Conclusion**:
- After analyzing all four options, we find that the only unicellular organism among them is amoeba. Thus, the answer to the question is amoeba.

**Final Answer**: Amoeba is the unicellular organism.

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