What do all unicellular organisms have in common ?

Explanation

### Step-by-Step Solution:

1. **Definition of Unicellular Organisms**:
- Unicellular organisms are defined as organisms that consist of only one cell. This single cell is responsible for all the life processes necessary for survival.

2. **Life Processes in a Single Cell**:
- Since unicellular organisms have only one cell, all life processes such as metabolism, reproduction, and response to the environment must occur within this single cell.

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