Which of the following is not a component of downstream processing?
Answer: (D) Expression. Answer: (D) Expression Solution: After the biosynthetic (fermentation) stage, the product is taken through separation and purification, followed by formulation with preservatives and quality control — these steps are collectively called downstream processing.
- A.Separation
- B.Purification
- C.Preservation
- D.Expression✓
Correct Answer
(D) Expression
Solution & Explanation
Answer: (D) Expression Solution: After the biosynthetic (fermentation) stage, the product is taken through separation and purification, followed by formulation with preservatives and quality control — these steps are collectively called downstream processing. Separation and purification are explicitly named as downstream processing. 'Expression' of the foreign gene is part of obtaining the gene product (an upstream/biosynthetic event), not downstream processing, so (D) is the odd one out. NCERT Reference: Ch 9, p.175, line(s) 45 — "include separation and purification, which are collectively referred to as downstream processing"