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Question #46721
The Question
The Endosymbiotic Theory posits that mitochondria evolved from free-living aerobic bacteria, a lineage supported by their possession of circular DNA and 70S ribosomes. Mycoplasma also exhibits a highly reduced genome with a 70S translation apparatus. Which of the following statements regarding their evolutionary biology and genetic machinery is INCORRECT?
Options
- A.
Both mitochondria and Mycoplasma utilize 70S ribosomes, which are structurally distinct from the 80S ribosomes found in the eukaryotic cytoplasm.
- B.
The evolutionary genome reduction in mitochondria involved the horizontal transfer of many ancestral bacterial genes to the eukaryotic host nucleus.
- C.
Despite its minimal genome, Mycoplasma retains the complete genetic blueprint required for independent survival, whereas mitochondria are obligate intracellular organelles.
- D.
Because mitochondria possess their own circular DNA and 70S ribosomes, they are completely autonomous in synthesizing all the ribosomal proteins required for their own translation machinery.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Ribosome Svedberg Coefficient|Evolutionary_Exception|Mitochondria|Mycoplasma
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse 'possessing DNA and ribosomes' with 'complete genetic autonomy'.
Because NCERT states mitochondria have their own DNA and ribosomes to synthesize some proteins, students fall into the trap of assuming they synthesize all components of their own machinery.
This ignores the critical NCERT keyword 'semi-autonomous' and the evolutionary reality of gene transfer to the host nucleus.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell – The Unit of Life - Class 11 |
| Concept | Ribosome Svedberg Coefficient |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |