MCQ Questions on Molecular Basis Of Inheritance
1. The nucleic acid synthesis takes place in
(a) 3’-5’ direction
(b) 5’-3’ direction
(c) Both ways
(d) Any direction
Answer
Answer: (b) 5’-3’ direction
2. What is the nature of the strands of the DNA duplex?
(a) Anti-parallel and complementary
(b) Identical and complementary
(c) Anti=parallel and non-complementary
(d) Dissimilar and non-complementary
Answer
Answer: (a) Anti-parallel and complementary
3. Hershey and Chase’s experiment was based on the principle
(a) Transformation
(b) Translation
(c) Transduction
(d) Transcription
Answer
Answer: (c) Transduction
4. AUG stands for
(a) Alanine
(b) Methionine
(c) N-formyl methionine
(d) Glycine
Answer
Answer: (b) Methionine
5. The reason behind the anti-parallel strand of DNA is
(a) Hydrogen bond
(b) Ionic bond
(c) Phosphodiester bond
(d) Disulphide bond
Answer
Answer: (a) Hydrogen bond
6. In a transcription unit, the promoter is located towards
(a) 5’end of the structural gene
(b) 3’end of the structural gene
(c) 5’end of the template strand
(d) 3’end of the coding strand
Answer
Answer: (a) 5’end of the structural gene
7. The primer in DNA replication is
(a) Small ribonucleotide polymer
(b) Helix destabilizing protein
(c) Small deoxyribonucleotide polymer
(d) Enzyme joining nucleotides of new strands
Answer
Answer: (a) Small ribonucleotide polymer
8. Genetic information is transferred from nucleus to cytoplasm through
(a) RNA
(b) Anticodon
(c) DNA
(d) Lysosomes
Answer
Answer: (a) RNA
9. The enzyme involved in transcription
(a) DNA Polymerase I
(b) DNA Polymerase III
(c) RNA Polymerase
(d) DNA Polymerase II
Answer
Answer: (c) RNA Polymerase
10. Non-sense codons participate in
(a) Releasing t-RNA from polynucleotide chain
(b) Formation of unspecified amino acids
(c) Terminating message of gene-controlled protein synthesis
(d) Conversion of sense DNA into non-sense DNA
Answer
Answer: (c) Terminating message of gene-controlled protein synthesis
11. The proofreading enzyme in DNA replication is
(a) Primase
(b) DNA Polymerase I
(c) Ligase
(d) DNA Polymerase II
Answer
Answer: (b) DNA Polymerase I
12. Select a ribozyme
(a) Peptidyl transferase
(b) Helicase
(c) Ribonuclease-P
(d) Both (a) and (c)
Answer
Answer: (d) Both (a) and (c)
13. Which step does not occur in translation?
(a) Replication
(b) Termination
(c) Elongation
(d) Initiation
Answer
Answer: (a) Replication
14. Select the incorrectly matched pairs
(a) Purines – Nitrogenous bases cytosine, thymine and uracil
(b) Recombinant DNA – DNA formed by joining the DNA segments from two different sources
(c) rRNA – RNA found in ribosomes
(d) ATP – The energy-carrying compound in the cell
Answer
Answer: (a) Purines – Nitrogenous bases cytosine, thymine and uracil
15. The energy source for the elongation process is
(a) Creatine-PO4
(b) GTP
(c) ATP
(d) All of the above
Answer
Answer: (b) GTP
16. The anticodon of initiation codon for protein synthesis is
(a) UUU
(b) AUG
(c) UAC
(d) CAU
Answer
Answer: (c) UAC
17. In lac-operon, which protein is not regulated by the repressor?
(a) Galactosidase
(b) Lactose Permease
(c) Tryptophan
(d) Transacetylase
Answer
Answer: (c) Tryptophan
18. Which enzyme is not produced during lactose catabolism by E.coli?
(a) 𝜷-galactosidase
(b) Lactose Permease
(c) Thiogalactoside transacetylase
(d) Lactose dehydrogenase
Answer
Answer: (d) Lactose dehydrogenase
19. The eukaryotic replication of DNA is
(a) Bidirectional with many origins
(b) Unidirectional with many origins
(c) Bidirectional with a single origin
(d) Unidirectional with a single origin
Answer
Answer: (a) Bidirectional with many origins
20. The amino acid coded by 3 codons is
(a) Proline
(b) Isoleucine
(c) Tryptophan
(d) Serine
Answer
Answer: (b) Isoleucine
21. Spliceosomes are absent in the cells of
(a) Plants
(b) Animals
(c) Bacteria
(d) Fungi
Answer
Answer: (c) Bacteria
22. A molecule that acts as a genetic material must fulfil the following traits, except
(a) It should be structurally and chemically unstable
(b) It should have the ability to generate its replica
(c) It should facilitate slow changes necessary for evolution.
(d) It should be able to express itself in the form of Mendelian characters.
Answer
Answer: (a) It should be structurally and chemically unstable
23. What will the amount of guanine in a DNA if the total amount of adenine and thiamine in the DNA is 45%?
(a) 45%
(b) 65%
(c) 27.5%
(d) 22.3%
Answer
Answer: (c) 27.5%
24. The primary control of gene expression takes place at the level of
(a) Translation
(b) Replication
(c) Transcription
(d) None
Answer
Answer: (c) Transcription
25. The gene sequence that codes for proteins are
(a) Exons
(b) Introns
(c) Intervening sequences
(d) Control regions
Answer
Answer: (a) Exons
26. The process of RNA splicing shows the dominance of
(a) RNA world
(b) DNA world
(c) Microbial world
(d) Protein world
Answer
Answer: (a) RNA world
27. In eukaryotes, RNA II facilitates transcription of
(a) rRNA
(b) mRNA
(c) hnRNA
(d) tRNA
Answer
Answer: (c) hnRNA
28. Human Genome Project led to the development of
(a) Biotechnology
(b) Bioinformatics
(c) Biosystematics
(d) Bioengineering
Answer
Answer: (b) Bioinformatics
29. Which non-radioactive isotope was used by Messelson and Stahl in their experiment?
(a) P32
(b) S35
(c) N15
(d) None
Answer
Answer: (c) N15
30. Histones are
(a) Positively charged and basic amino acids
(b) Positively charged and acidic proteins
(c) Negatively charged and basic proteins
(d) Absent in bacteria
Answer
Answer: (d) Absent in bacteria