List two similarities between mitochondria and plastids.

Explanation

**Step-by-Step Text Solution:**

1. **Identify the Organelles**: Mitochondria and plastids are both important organelles found in cells. Mitochondria are often referred to as the "powerhouses" of the cell, while plastids are primarily involved in the synthesis and storage of food in plant cells.

2. **First Similarity - Double Membrane**: Both mitochondria and plastids are double membrane-bound organelles. This means that each of these organelles is surrounded by two layers of membranes, which is a common structural feature that they share.

3. **Second Similarity - Protein Production**: Both organelles have the capability to produce their own proteins. This is due to the presence of their own DNA, RNA, ribosomes, and enzymes, which allow them to synthesize proteins independently from the cell's nuclear DNA.

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