Before You Begin

Question #131948

Difficulty: 8/10 | 🟢 Free

The Question

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

Assertion (A): In large-scale stirred-tank bioreactors, inadequate mixing geometry during the batch feeding of glucose leads to highly variable yields of recombinant proteins whose genes are cloned downstream of a lac promoter. Reason (R): Non-homogenous glucose distribution creates localized zones of carbon catabolite repression, which lowers intracellular cAMP levels and prevents the positive regulation of the lac promoter.

In the light of the above statements, choose the most appropriate answer from the options given below:

Options

A.
Both (A) and (R) are correct and (R) is the correct explanation of (A)
B.
Both (A) and (R) are correct but (R) is not the correct explanation of (A)
C.
(A) is correct but (R) is not correct
D.
(A) is not correct but (R) is correct

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Regulatory_Failure

Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.

Concepts Behind This Question

Bioreactor Geometry|Glucose Repression|Baculovirus Host Specificity

Why This Question Is Tricky

Examiner Levers

Logical Assertion

Tests the causal relationship between two true statements.

Difficulty Boost : +4

Common Mistakes

Conceptual Pivot: This question tests the synthesis of Molecular Genetics (Lac Operon regulation) with Biotechnology (Bioreactor mass transfer).

Students often memorize that 'glucose is a preferred substrate' but fail to apply the mechanism of positive control (cAMP-CAP) to a macroscopic industrial scale.

The trap lies in understanding that physical bioreactor geometry directly impacts molecular epigenetic switching.

Quick Facts About This Question

Question Information

Subject	Biology
Chapter	Biotechnology : Principles and Processes - Class 12
Concept	Bioreactor Geometry
Difficulty	8
Cognitive Load	5
Target Solve Time	120 sec
Access	Free