NEET 2023 Phase 2 · BiologyPrevious Year Question
Name the component that binds to the operator region of an operon and prevents RNA polymerase from transcribing the operon.
Answer: (A) Repressor protein. Answer: (A) Repressor protein.
- A.Repressor protein✓
- B.Inducer
- C.Promotor
- D.Regulator protein
Correct Answer
(A) Repressor protein
Solution & Explanation
Answer: (A) Repressor protein. In the lac operon, the repressor protein (product of the i gene) binds to the operator region and blocks RNA polymerase from transcribing the operon; an inducer inactivates the repressor. NCERT Ch 5, p.101, lines 012-013: "The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon."
🎯
43,000+ questions in हिंदी & English · one-tap toggle
Open →📚Practice all NEET Biology PYQs chapter-wise →💡Don't get it? Learn the Molecular Basis of Inheritance concepts →Practice NEET 2023 Phase 2 Biology — free, with instant solutions
43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.
More NEET PYQ solutions
BiolWhich one of the following is an example of ex-situ conservation?BiolWhich of the following is an example of a zygomorphic flower? (NEET 2025)BiolWhich of the following is an example of actinomorphic flower? (NEET 2024)BiolIn the seeds of cereals, the outer covering of endosperm separates the embryo by a protein-rich layer called : (NEET 2025)BiolGiven below are two statements: Statement I : In a floral formula the symbol [percentage/division-type symbol] stands for zygomorphic nature of the flower, and G with a bar above it stands for inferior ovary. Statement II : In a floral formula the symbol [same symbol] stands for actinomorphic nature of the flower and G with a bar below it stands for superior ovary. In the light of the above statements, choose the correct answer from the options given below: (NEET 2025)BiolMatch List I with List II: List I — A. Scutellum; B. Non-albuminous seed; C. Epiblast; D. Perisperm. List II — I. Persistent nucellus; II. Cotyledon of Monocot seed; III. Groundnut; IV. Rudimentary cotyledon. Choose the option with all correct matches. (NEET 2025)BiolGiven below are the stages in the life cycle of pteridophytes. Arrange the following stages in the correct sequence. A. Prothallus stage B. Meiosis in spore mother cells C. Fertilisation D. Formation of archegonia and antheridia in gametophyte. E. Transfer of antherozoids to the archegonia in presence of water. Choose the correct answer from the options given below:BiolThe correct sequence of events in the life cycle of bryophytes is A. Fusion of antherozoid with egg. B. Attachment of gametophyte to substratum. C. Reduction division, to produce haploid spores. D. Formation of sporophyte. E. Release of antherozoids into water. Choose the correct answer from the options given below: