Before You Begin
Question #46430
The Question
The Oparin-Haldane hypothesis states that chemical evolution required a reducing atmosphere on primitive Earth. If a localized geochemical event prematurely introduced high levels of free oxygen () into the primordial soup prior to the establishment of the RNA-world, which of the following would be the most direct consequence on the sequence of abiogenesis?
Options
- A.
The transition from monomeric chemical evolution to cellular biogenesis would be halted due to the oxidative degradation of nitrogenous bases.
- B.
The rate of formation of complex organic polymers would increase due to oxygen acting as a catalyst for dehydration synthesis.
- C.
A premature shift from the RNA-world to the DNA-world would occur, as double-stranded DNA is more resistant to oxidative damage.
- D.
Chemoheterotrophic coacervates would immediately evolve aerobic respiration pathways to neutralize the toxic oxygen.
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
Oparin-Haldane|Coacervates|Prokaryotic_Origin
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that the early atmosphere was 'reducing' without understanding the biochemical 'why'.
The misconception is failing to recognize that free oxygen acts as a potent destructive agent (oxidizing agent) against unprotected organic monomers.
The trap in Option C plays on the true fact that DNA is more stable than RNA, but applies it to an impossible timeline where polymers haven't even formed yet.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Evolution - Class 12 |
| Concept | Chemical Evolution Sequence |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |