Paramecium is a ............ organism.

Options

A. unicellular
B. multicellular
C. invertebrates
D. mammal

Explanation

**Step-by-Step Solution:**

1. **Identify the Organism**: The question asks about Paramecium. We need to understand what type of organism it is.

2. **Define Unicellular Organisms**: Unicellular organisms are defined as organisms that consist of a single cell. They are also known as single-celled organisms.

3. **Categorize Unicellular Organisms**: Unicellular organisms can be further classified into two categories: prokaryotic and eukaryotic.

4. **Determine the Classification of Paramecium**: Paramecium is classified as a eukaryotic organism. This means that its cells have a nucleus and other organelles enclosed within membranes.

5. **Describe the Characteristics of Paramecium**: Paramecium is shaped like a shoe sole and typically ranges in size from 50 to 300 micrometers, depending on the species. It is commonly found in freshwater environments.

6. **Conclude the Answer**: Based on the information gathered, we can conclude that Paramecium is a unicellular organism.

**Final Answer**: Paramecium is a unicellular organism.

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