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Question #47509
The Question
The Endosymbiotic Theory explains the origin of mitochondria and chloroplasts from free-living prokaryotes. Over evolutionary time, Endosymbiotic Gene Transfer (EGT) led to a massive reduction in the ancestral endosymbiont's genome. Based on the structural and functional characteristics of modern plastids and mitochondria, which of the following statements is INCORRECT?
Options
- A.
Porins form large pores in the outer membranes of plastids, mitochondria, and some bacteria, providing structural evidence of their shared evolutionary lineage.
- B.
They divide by fission and possess a single, circular, double-stranded DNA molecule that lacks association with histone proteins.
- C.
To protect critical metabolic machinery from oxidative damage, all genes encoding the electron transport chain and photosystem core proteins were transferred to the host nucleus.
- D.
They are classified as semi-autonomous organelles because, despite having 70S ribosomes, they depend on nuclear-encoded proteins for the majority of their structural and metabolic functions.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Chlorophyll_a_b|C4_Cycle|PEP_Carboxylase
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: The definition of 'Semi-autonomous'.
Students often misunderstand the extent of Endosymbiotic Gene Transfer.
While most genes moved to the nucleus, the organelle MUST retain genes for core, highly hydrophobic, or rapidly degrading ETC/photosystem proteins.
If Option C were true, the organelles would be completely dependent (like a lysosome or Golgi), not semi-autonomous.
The trap leverages the plausible-sounding logic of 'protecting genes from oxidative damage' to mask the biological reality of local translation requirements.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Algal Pigmentation Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |