Why are the mitochondria and plastids called semiautonomous organelles?

Explanation

### Step-by-Step Solution:

1. **Definition of Semiautonomous Organelles**:
- Semiautonomous organelles are those organelles that can replicate and maintain themselves independently to some extent, but still rely on the cell for certain functions and components.

2. **Examples of Semiautonomous Organelles**:
- The two main examples of semiautonomous organelles are mitochondria and plastids (which include chloroplasts).

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