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ICAR JRF Biochemistry 29 Jun 2024Shift 1
Assertion & Reason +4 −1

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).

Assertion (A) : Archaebacteria survive on extreme conditions like high temperature and low pH
Reason (R) : Archaebacteria have unique membrane lipids linked through ester bonds that is more stable than ether bonds found in other lipids

In light of the above statements, choose the correct answer from the options given below.

  • Assertion (A) is True: Archaebacteria (Archaea) thrive in extreme terrestrial and marine environments, including hyperthermal vents ($\gt 100^\circ\text{C}$), hypersaline lakes, and highly acidic solfataras (pH $\lt 2$).
  • Reason (R) is False: Archaebacterial cell membranes possess unique isoprenoid phytanyl chains linked to glycerol via ether bonds ($-\text{C}-\text{O}-\text{C}-$), NOT ester bonds. Ether linkages and cyclopentane rings provide far greater chemical resilience against thermal degradation and acid hydrolysis than the ester bonds ($-\text{COO}-$) found in eubacteria and eukaryotes.
  • Conclusion: (A) is true but (R) is false.

Correct option: (3) (A) is true but (R) is false.

Explanation not matching this question? क्या व्याख्या इस प्रश्न से मेल नहीं खा रही? Report
Want to practice this paper in exam conditions? क्या आप परीक्षा जैसे माहौल में अभ्यास करना चाहते हैं? Test yourself in 5-question batch format with timer and hidden answers. 5-प्रश्नों के बैच फॉर्मैट, टाइमर और छिपे उत्तरों के साथ खुद को परखें।
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