Question
Write short notes on:
- Mitochondria.
- Plastids.
✓
Answer
- Mitochondria: The mitochondria are tiny bodies of varying shapes and size. Each mitochondria is bounded by a double membrane envelope. Outer membrane is porous. The inner membrane is thrown into folds. These folds are called cristae and are studded with small rounded bodies known as $F_1$ particles or oxysomes. The interior cavity of the mitochondria is filled with a proteinaceous matrix which contains a few small-sized ribosomes, a circular $DNA$ molecule and phosphate granules. Mitochondria are sites of cellular respiration.
- Plastids: Plastids occur in most plant cells and are absent in animal cells. They have their own genome and ribosomes. There are three types of plastids: chromoplasts, chloroplasts and leucoplasts.
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