Tag: operon pyq

32. When tryptophan in excess most of times RNA polymerase dismount after transcription of first 150 nt in trp operon. This is termed as (1) Anti-termination (2) Attenuation (3) Catabolite […]

You have created a fusion between the trp operon, which encodes the enzymes for trptophan biosynthesis, under the regulatory control of the lac operator. Under which of the following conditions […]

30. A heterozygote of E.coli was produced with the following combination of mutations: trpR+ trpO– trpE+ / trpR+ trpO+ trpE– Where R is the repressor, O is the operator and […]

29. A mutant Trp repressor (TrpRm) that cannot bind tryptophan is isolated. In this mutant A. Trp operon is constitutively expressed. B. Trp operon is super-repressed. C. Trp repressor does […]

In Trp operon, binding of tryptophan to trp repressor lead to (1) Repression (2) Induction (3) Anti termination (4) Attenuation   Introduction The trp operon in Escherichia coli is a classic model […]

Which of the following is negative regulator of trp operon (1) Lactose (2) Allolactose (3) C-AMP (4) Tryptophan   The trp operon in Escherichia coli is a classic example of negative gene […]

26. In trp operon regulation excess tryptophan act as (1) Inducer         (2) Activator (3) Repressor      (4) Co-repressor   Introduction: The trp Operon and Its Regulatory Logic The trp operon in Escherichia […]

25. The Lac I and TrpR repressors bind With their ligands allolactose and tryptophan respectively, resulting in alteration of their DNA binding properties. The following statements are made about the […]

24. E. coli mutants isolated from a genetic screen showed following classes of mutations A. Point mutations in lacI B. Deletions immediately downstream of the transcription start site of the […]

23. In an experimental approach regulatory sequences of trp operon were fused with structural genes of lac operon. Under what condition there would be expression Of β-galactosidase? (1) Low lactose […]