Mitochondria and chloroplasts are semi- autonomous as they possess

Options

A. DNA
B. DNA + RNA
C. DNA + RNA + ribosomes
D. Proteins

Answer

**Step-by-Step Solution:**

1. **Definition of Semi-Autonomous Organelles**: Mitochondria and chloroplasts are referred to as semi-autonomous organelles because they can replicate and perform certain functions independently within the cell.

2. **Presence of Genetic Material**: Both mitochondria and chloroplasts contain their own DNA. This genetic material is essential for the synthesis of some of their proteins and enzymes, which allows them to carry out specific functions.

3. **Ribosomes and Protein Synthesis**: In addition to DNA, these organelles also possess their own ribosomes. These ribosomes are similar to those found in prokaryotic cells, which allows mitochondria and chloroplasts to synthesize some of their own proteins.

4. **Double Membrane Structure**: Mitochondria and chloroplasts are surrounded by a double membrane. This structure is significant because it indicates their evolutionary origin from prokaryotic cells that were engulfed by ancestral eukaryotic cells.

5. **Evolutionary Perspective**: The endosymbiotic theory suggests that mitochondria and chloroplasts originated from free-living bacteria that were taken up by a host cell. Over time, these bacteria became integral parts of the cell, leading to the semi-autonomous nature of these organelles.

6. **Functional Independence**: Although they rely on the cell for some functions and resources, the presence of their own DNA and ribosomes allows mitochondria and chloroplasts to perform critical roles—such as ATP production in mitochondria and photosynthesis in chloroplasts—independently.

**Final Answer**: Mitochondria and chloroplasts are semi-autonomous because they possess their own DNA and ribosomes, allowing them to synthesize some proteins independently and perform essential functions within the cell.

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