Biochemistry

GENETIC REGULATION PROKARYOTES MCQs

Total Questions : 22

Page 1 of 3 pages
Question 1. Sex lethal (sxl) in Drosophila is transcribed when
  1.    None of these
  2.    the X autosome balance is less than 0.5
  3.    the X autosome balance is 1 or greater
  4.    the X autosome balance equals 0.5
 Discuss Question
Answer is Option C. -> the X autosome balance is 1 or greater
Question 2. A mutation in the tip binding site of the repressor would result in
  1.    inducible trp operon expression
  2.    None of these
  3.    constitutive trp operon expression
  4.    no operon expression
 Discuss Question
Answer is Option C. -> constitutive trp operon expression
Question 3. Which of the following is not part of the lac operon?
  1.    O
  2.    none of these
  3.    I
  4.    P
 Discuss Question
Answer is Option C. -> I
Question 4. The lac operon is transcribed in which segments?
  1.    3
  2.    1
  3.    2
  4.    4
 Discuss Question
Answer is Option B. -> 1
Question 5. The first protein complex to bind to the TATA box is
  1.    transcription factor IIB
  2.    transcription factor IIA
  3.    all of these
  4.    transcription factor IID
 Discuss Question
Answer is Option D. -> transcription factor IID
Question 6. Genes which need to be coordinately regulated but are not in operons may be regulated by
  1.    GC regions
  2.    common transcription factor binding domains
  3.    CAAT regions
  4.    TATA boxes
 Discuss Question
Answer is Option B. -> common transcription factor binding domains
Question 7. Tubulin is regulated by
  1.    binding of tubulin to DNA
  2.    binding of tubulin to the tubulin translational product
  3.    binding of tubulin to tubulin mRNA
  4.    splicing of the tubulin transcript
 Discuss Question
Answer is Option B. -> binding of tubulin to the tubulin translational product
Question 8. A frameshift mutation occurs in the sigma subunit gene transcribed as part of SPOl early genes. What will be the immediate result?
  1.    Early genes will not be translated
  2.    The bacterial host will lyse immediately
  3.    Infection will proceed as usual
  4.    Middle genes will not be transcribed
 Discuss Question
Answer is Option B. -> The bacterial host will lyse immediately
Question 9. In the presence of high levels of tryptophan
  1.    None of these
  2.    attenuator terminates transcription
  3.    attenuator propogates transcription
  4.    attenuator allows transcription of trp structural genes
 Discuss Question
Answer is Option B. -> attenuator terminates transcription
Question 10. What are genes?
  1.    A fragment of DNA
  2.    The functional unit of inheritance
  3.    A portion of a chromosome
  4.    All of these
 Discuss Question
Answer is Option D. -> All of these