1. Topoisomerase is involved in:
a. Producing RNA primer
b. Joining of DNA segment
c. Producing nick in DNA
d. Separation of DNA strand
Answer: c. Producing nick in DNA
2. What is the functional unit of a gene?
a. Cistron
b. Muton
c. Recon
d. Codon
Answer: a. Cistron
3. Choose the correct statement regarding the Okazaki fragment:
a. RNA primers
b. Short DNA fragments on leading strand
c. Short DNA fragments on lagging strand
d. DNA fragments from radiation action
Answer: c. Short DNA fragments on lagging strand
4. Change in the sequence of nucleotides of DNA is:
a. Mutagen
b. Recombination
c. Mutation
d. Translation
Answer: c. Mutation
5. In lac operon; lactose of lac operon acts as…?
a. Inducer
b. Repressor
c. Co-inducer
d. Co-Repressor
Answer: c. Co-inducer
6. In some viruses RNA is present instead of DNA indicating that…?
a. nuclei acid combine with host DNA before replication
b. They cannot replicate
c. There is no hereditary information
d. RNA can act to transfer hereditary
Answer: d. RNA can act to transfer hereditary
7. Which of the following bonds are important for DNA to maintain a double helix structure?
a. Hydrogen bond
b. Covalent bond
c. Disulfide bonds
d. Van der Waals forces
Answer: a. Hydrogen bond
8. Double hydrogen bond occurs in DNA between…?
a. Adenine and thymine
b. Uracil and thymine
c. Adenine and guanine
d. Thymine and cytosine
Answer: a. Adenine and thymine
Recommended: Molecular Basis of Inheritance Practice Test
9. The number of hydrogen bonds between Guanine and Cytosine…?
a. 1
b. 2
c. 3
d. 4
Answer: c. 3
10. Hereditary information is indicated by…?
a. Number of nuclei acid
b. Position of nuclei acid
c. Sequence of nuclei acid
d. All of these
Answer: d. All of these
11. Which of the following mutation at one base of the first codon of a gene forms a non-functional protein?
a. Nonsense mutation
b. Reverse mutation
c. Frameshift mutation
d. Mis-sense mutation
Answer: d. Mis-sense mutation
12. DNA synthesis can be measured by estimating the incorporation of radiolabeled:
a. Uracil
b. Ribose sugar
c. Thymidine
d. Adenine
Answer: c. Thymidine
13. A tRNA recognizes ribosomes by…?
a. TC loop
b. DHU loop
c. Anticodon
d. AA-site
Answer: a. TC loop
14. Which enzyme is required for removing RNA primer during DNA replication?
a. Primase
b. Ligase
c. DNA polymerase I
d. DNA polymerase III
Answer: c. DNA polymerase I
15. Beadie and Tatum produce a mutant strain of Neurospora by using…?
a. X-rays
b. UV rays
c. Beta rays
d. Gamma rays
Answer: a. X-rays
16. Maximum formation of RNA occurs in…?
a. Cytoplasm
b. Nucleoplasm
c. Nucleolus
d. Ribosome
Answer: c. Nucleolus
17. What direction are nucleic acids synthesized?
a. 3-5 direction
b. 4-3’ direction
c. 5’-3’ direction
d. 6’-3’ direction
Answer: c. 5’-3’ direction
18. What is the nature of the strands of the DNA duplex?
a. Anti-parallel and complementary
b. Identical and complementary
c. Dissimilar and non-complementary
d. Antiparallel and non-complementary
Answer: a. Anti-parallel and complementary
19. On which principle Hershey and Chase’s experiment was based?
a. Transduction
b. Transformation
c. Translation
d. Transcription
Answer: a. Transduction
20. The DNA strands are anti-parallel because of…?
a. Hydrogen bond
b. Phosphodiester bond
c. Ionic bond
d. Disulfide bond
Answer: b. Phosphodiester bond
21. What is the location of the promoter in the transcription unit??
a. 3’end of the structural gene
b. 5’end of the structural gene
a. 5’end of the template strand
b. 3’end of the coding strand
Answer: b. 5’end of the structural gene
22. Choose the correct statement regarding the primer in DNA replication:
a. Helix destabilizing protein
c. Small deoxyribonucleotide polymer
d. Small ribonucleotide polymer
e. Enzyme joining nucleotides of new strands
Answer: d. Small ribonucleotide polymer
23. Which of the following transfers genetic information from the nucleus to the cytoplasm?
a. Anticodon
b. DNA
c. RNA
d. Lysosomes
Answer: c. RNA
24. Transcription is carried out by which of the following enzyme?
a. DNA Polymerase I
b. DNA Polymerase III
c. DNA Polymerase II
d. RNA Polymerase
Answer: d. RNA Polymerase
25. Choose the correct statement regarding the function of a non-sense codon:
a. Releasing t-RNA from polynucleotide chain
b. Formation of unspecified amino acids
c. Conversion of sense DNA into non-sense DNA
d. Terminating message of gene-controlled protein synthesis
Answer: d. Terminating message of gene-controlled protein synthesis
26. Which of the following is a proofreading enzyme in DNA replication?
a. DNA Polymerase I
b. Ligase
c. Primase
d. DNA Polymerase II
Answer: a. DNA Polymerase I
27. Which of the following step is not involved in the translation of an mRNA molecule?
a. Replication
b. Termination
c. Elongation
d. Initiation
Answer: a. Replication
28. Choose the Incorrectly matched pairs from the following:
a. mRNA ↔ single-stranded RNA involved in protein synthesis
b. Purines ↔ Nitrogenous bases cytosine, thymine and uracil
c. rRNA ↔ RNA found in ribosomes
d. ATP ↔ The energy-carrying compound in the cell
Answer: b. Purines ↔ Nitrogenous bases cytosine, thymine and uracil
29. Which is the energy source for the process of elongation??
a. Creatine-PO4
b. ATP
c. GTP
d. All of these
Answer: c. GTP
30. Which of the following proteins is not regulated by the repressor in lac operon?
a. Galactosidase
b. Lactose Permease
c. Transacetylase
d. Tryptophan
Answer: d. Tryptophan
31. DNA replication in eukaryotes cells is…?
a. Unidirectional with many origins
b. Bidirectional with a single origin
c. Unidirectional with a single origin
d. Bidirectional with many origins
Answer: d. Bidirectional with many origins
32. Which of the following amino acid is coded by three codons?
a. Isoleucine
b. Proline
c. Tryptophan
d. Serine
Answer: a. Isoleucine
33. Spliceosomes are absent in the cells of…?
a. Bacteria
b. Plants
c. Animals
d. Fungi
Answer: a. Bacteria
34. Calculate the amount of guanine in DNA; if the total amount of adenine and thymine in double-stranded DNA is 60%.
a. 20%
b. 15%
c. 30%
d. 50%
Answer: b. 15%
35. The primary control of gene expression takes place at the level of…?
a. Translation
b. Transcription
c. Replication
d. None of these
Answer: b. Transcription
