Some organisms are composed of a single cell and are called (A)____ organisms while other organisms are composed of many cells are called (B)____ organisms.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks us to identify two types of organisms based on their cellular composition. One type consists of a single cell, and the other consists of multiple cells.

2. **Identifying Unicellular Organisms**: Organisms that are composed of only one cell are referred to as unicellular organisms. This means that all the life processes of these organisms are carried out by that single cell.

3. **Identifying Multicellular Organisms**: On the other hand, organisms that are composed of many cells are known as multicellular organisms. In these organisms, the functions are distributed among various cells, allowing for more complex structures and functions.

4. **Examples of Each Type**:
- An example of a unicellular organism is **Amoeba**. It performs all necessary life functions within that one cell.
- An example of a multicellular organism is **Humans**. They have specialized cells that perform different functions, contributing to the overall functioning of the organism.

5. **Final Answers**:
- (A) Unicellular
- (B) Multicellular