Questions and answers for exam Preparation

MCQs

Total Questions : 282 | Page 9 of 29 pages

Question 81. Transcription by E. coli polymerase occurs in

four phases known as initiation, propagation, elongation and termination
three phases known as initiation, elongation and termination
two phases known as initiation and termination
none of the above

Discuss Question

Answer: Option B. -> three phases known as initiation, elongation and termination
Answer: (b).three phases known as initiation, elongation and termination

Question 82. Enhancers are regions that

bind RNA polymerase
are adjacent to the TATA box
are CAT box binding proteins
modulate transcription

Discuss Question

Answer: Option D. -> modulate transcription
Answer: (d).modulate transcription

Question 83. The binding of lac repressor to DNA could be considered to be analogous to

competitive inhibition of an enzyme
mixed-type inhibition of an enzyme
uncompetitive inhibition of an enzyme
allosteric effects in enzyme regulation

Discuss Question

Answer: Option A. -> competitive inhibition of an enzyme
Answer: (a).competitive inhibition of an enzyme

Question 84. Which of the following is necessary for transcription to occur?

DNA molecule
RNA polymerase
DNA polymerase
Both DNA & RNA polymerase

Discuss Question

Answer: Option D. -> Both DNA & RNA polymerase
Answer: (d).Both DNA & RNA polymerase

Question 85. Rho-dependent termination of transcription in E. coli

requires ATP
requires about 50 nucleotides of uncomplexed mRNA
both (a) and (b)
removes mRNA and holoenzyme from the DNA

Discuss Question

Answer: Option C. -> both (a) and (b)
Answer: (c).both (a) and (b)

Question 86. Crick demonstrated that the genetic code involved three bases and suggested that the code was degenerated. What experimental technique Crick conducted to suggest genetic code degeneration?