(A)
P-4
Q-3
R-5
S-6

(B)
P-4
Q-3
R-2
S-1

(C)
P-2
Q-4
R-5
S-3

(D)
P-4
Q-2
R-6
S-1

Correct Answer

✅ Option (B)

Detailed Explanation

Crop improvement through genetic engineering involves the introduction of specific functional genes that confer targeted agronomic traits.

P. bar → Herbicide resistance (4)

• The bar gene encodes phosphinothricin acetyltransferase.

• It provides resistance against glufosinate (phosphinothricin) herbicides.

• ✔ Correct match: P-4

Q. vip3A → Insect resistance (3)

• vip3A is derived from Bacillus thuringiensis (Bt).

• It produces vegetative insecticidal proteins effective against lepidopteran pests.

• ✔ Correct match: Q-3

R. β-lcy → Nutritional improvement with increased vitamin A (2)

• β-lcy (beta-lycopene cyclase) is involved in carotenoid biosynthesis.

• It enhances β-carotene (pro-vitamin A) levels, as in Golden Rice.

• ✔ Correct match: R-2

S. gsh-II → Tolerance to heavy metals (1)

• gsh-II encodes glutathione synthetase.

• Glutathione plays a major role in detoxification of heavy metals.

• ✔ Correct match: S-1

Why Option (B) Is Correct

Option (B) correctly matches all four genes with their specific and well-established crop improvement traits.
All other options contain at least one incorrect association.

Quick Exam Memory Tips

• bar → Herbicide resistance

• vip3A → Insect resistance

• β-lcy → Vitamin A enrichment

• gsh-II → Heavy-metal tolerance

Exam Relevance

🔹 Frequently asked in CSIR-NET Life Sciences
🔹 Core topic in plant biotechnology & transgenic crops
🔹 High-yield match-the-following MCQs