Gene Expression And Regulation Test

Gene Expression And Regulation

This is online test 03 for CBSE class 12 Biology Molecular Basis of Inheritance (Gene expression and regulation).. There are 10 questions in this test with each question having around four answer choices.

Questions & Answers

1
If 30percent of an organism’s DNA is thymine, then
  • A
    30 percent is guanine
  • B
    30 percent is adenine
  • C
    Both b and c
  • D
    20 percent is guanine
    Correct
2
In biochemical genetics the term gene is being replaced by
  • A
    Template
  • B
    Cistron
    Correct
  • C
    Anticodon
  • D
    Genome
3
Select the two correct statements out of the four (a–d) given below about lac operon. (a) Glucose or galactose may bind with the repressor and inactivate it (b) In the absence of lactose the repressor binds with the operator region (c) The z-gene codes for permease (d) This was elucidated by Francois Jacob and Jacque Mono. The correct statements are
  • A
    a and b
  • B
    b and d
    Correct
  • C
    a and c
  • D
    b and c
4
E. coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because
  • A
    The lac operon is constitutively active in these cells
  • B
    They cannot transport lactose from the medium into the cell
  • C
    In the presence of glucose, E.coli cells do not utilize lactose
  • D
    They cannot synthesize functional beta galactosidase
    Correct
5
H-bonds between Cytosine and Guanine are
Question 5 figure 1
  • A
    1
  • B
    2
  • C
    4
  • D
    3
    Correct
6
Transcription of DNA into mRNA occurs in the nucleus of the cell but translation occurs in
  • A
    Cytoplasm
    Correct
  • B
    Golgi apparatus
  • C
    Mitochondria
  • D
    Nucleus
7
In lac operon, lactose is the substrate for enzyme beta-galactocidase and its regulates
  • A
    Only switching ON of the operon
  • B
    Neither switching ON or OFF of operon
  • C
    Switching ON and OFF of the operon
    Correct
  • D
    Only switching of OFF of the operon
8
Lac operon consists of
  • A
    Only two regulator genes
  • B
    One regulator and one structural gene
  • C
    One regulator gene and three structural genes
    Correct
  • D
    Two regulator gene and two structural genes
9
Assertion: Regulation of lac operon by repressor is referred to as negative regulation. Reason: Lac operon is under the control of positive regulation as well.
  • A
    Both assertion and reason are incorrect
  • B
    Assertion is correct but reason is incorrect
  • C
    Both assertion and reason are correct
    Correct
  • D
    Assertion is incorrect but reason is correct
10
The correct sequence of gene expression is a. Formation of primary transcript b. Regulation of splicing c. Transport of mRNA from nucleus to cytoplasm> d. Translation
  • A
    b>c>a>d
  • B
    c>d>a>b
  • C
    a>b>c>d
    Correct
  • D
    d>c>b>a