Define. Cell

Explanation

### Step-by-Step Text Solution:

1. **Definition of a Cell**: A cell is defined as the basic structural and functional unit of life. This means that all living organisms are made up of cells, which are the smallest units that can carry out all the processes necessary for life.

2. **Importance of Cells**: Cells are crucial because they form the building blocks of all living organisms. In multicellular organisms, cells group together to form tissues, which in turn combine to form organs. These organs then work together to create organ systems, ultimately leading to the formation of a complete organism.

3. **Types of Organisms**:
- **Multicellular Organisms**: In these organisms, there are many cells that work together to perform various functions. Each cell has a specific role that contributes to the overall functioning of the organism.
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