A hypothetical operon involved in the synthesis of an amino acid ‘X’ is ‘ON’ (transcribing) in the presence of low levels of ‘X’ and ‘Off’ (not transcribing) in presence of […]
Tag: operon pyq
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CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
The Science of Color Development in E. coli: LacZ, X-gal, ONPG, and MacConkey Agar Explained
19. Which one of the following statements relating to the mechanism of color development in response to LacZ expression in Escherichia coli is INCORRECT? (1) E. coli growth on LB […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Decoding lac Operon Merodiploid Expression: Which Combinations of I, O, Z, and Y Mutations Are Correct?
The following statements are made with respect to merodiploids of the lac operon, where “I” is the lac repressor, “O” is the lac operator, “Z” is the lacZ gene encoding […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Phenotype of E. coli I– O+ Z+ Y– / F’ I+ OC Z– Y+ Merodiploid: Constitutive or Inducible?
20. With reference to lac operon, what will be the phenotype of an E. coli strain having a genotype I– O+ Z+ Y– /F’ I+ OC Z– Y+ ? (1) […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
LacZ Expression in E. coli Detection by X-gal, ONPG, and MacConkey Agar
19. Which one of the following statements relating to the mechanism of color development in response to LacZ expression in Escherichia coli is INCORRECT? (1) E. coli growth on LB […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Understanding lacY Mutants in E. coli: β-Galactosidase Synthesis and Lactose Permease Function
Mutants of lac Y (Y–) gene of E. coli do not synthesize the lactose permease protein. The following statements refer to the behaviour of lac mutants under different experimental conditions. […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
β-Galactosidase Expression in lac Operon Mutants and Merodiploid E. coli: Understanding OCI+Z– and O+I–Z+ Genotypes
In context to lac operon. if two bacterial strains P1 and P2 with the genotypes OCI+Z– and O+I–Z+ respectively, were used to produce mero-diploid daughter strain D, which one of […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Decoding E. coli Growth Curves: Glucose, Galactose, and Phage Infection Dynamics
16. E.coli was grown in three different experimental conditions. In one, it was grown in medium Containing as carbon source; in the second in medium containing both glucose and galactose; […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Lac Repressor vs. Pur Repressor: Key Differences in Gene Regulatory Mechanisms
15. Lac repressor inhibits expression of genes lac-operon whereas purine biosynthesis is repressed by the Pur repressor. The two sequences and have Similar three dimensional The gene regulatory properties of […]
CSIR NET Life Science Previous Year Questions and Solution on Molecular Biology
Growth Curve of lacI Mutant E. coli in Glucose and Lactose
14. The following figure represent the growth curve of wild type E.coli grown in a medium containing both glucose and lactose. In E.coli, the catabolite repression of lactose Operon by […]
