Are you looking for Molecular Basis of Inheritance Questions and Answers for NEET and other medical entrance examinations? If yes, these are some most important multiple choice questions and answers on NCERT Class-12 Biology, Chapter-6 (Molecular Basis of Inheritance).
Here we composed these 100+ MCQs and Answers on the Molecular Basis of Inheritance after reading the chapter on Molecular Basis of Inheritance from the NCERT book on Class 12 Biology. The questions are topics-wise and the students can relate the questions easily to the most important topics of this chapter.
Molecular Basis of Inheritance NEET Questions with Answers
DNA MCQ and Answers
1. Who was the first person to analyse factors?
2. In which year, the mechanism for genetic inheritance reached the molecular level?
3. What is the full form of DNA?
a) Degenerative acid
b) Deoxyribonucleic acid
c) Deadly nucleic acid
d) Disoriented acid
4. How many types of nucleic acids are present in the living systems?
5. Which of the following is not a function of RNA?
6. Which of the following is not a correct statement with respect to DNA?
a) It is a long polymer
b) It is found in the nucleus
c) It is a basic substance
d) First identified by Friedrich Meischer
7. Which of the following is the characteristic feature of an organism?
a) Number of RNA
b) Number of protein molecules
c) Length of chromosomes
d) Length of DNA
8. How many numbers of nucleotides are present in Lambda phage?
a) 48502 bp
b) 98526 bp
c) 10000 bp
d) 5326 bp
9. Which of the following is correct with respect to the genetic material of ?174 bacteriophage?
a) ss DNA, linear
b) ss RNA, linear
c) ss DNA, circular
d) ds DNA, linear
10. How many components are present in the basic unit of DNA?
11. Which of the following statements is correct with respect to purines?
a) Purines are heterocyclic compounds
b) Purines are 7 membered structure
c) Purines are single-ring structure
d) Thymine is an example of purine
12. Which of the following statement is incorrect with respect to pyrimidines?
b) 7 membered ring
c) Cytosine is an example of pyrimidine
d) Single-ring structure
13. By which of the following bonds, a nitrogenous base is linked to the pentose sugar?
a) Phosphate bond
b) Ester bond
c) Peptide bond
d) N-glycosidic bond
Structure of a Polynucleotide Chain MCQ and Answers
14. Through which among the following linkages are the two nucleotides connected through the 3’-5’ end?
a) Phosphodiether linkage
b) Phosphodisulphide linkage
c) Phosphodinitrate linkage
d) Phosphodiester linkage
15. What is chemical name for thymine known as?
a) 5-methoxy uracil
b) 3-methoxy uracil
c) 5-methyl uracil
d) 3-methy uracil
16. Who considered DNA as a “Nuclein”?
a) James Watson
b) Friedrich Meischer
c) Francis Crick
d) Rosalind Franklin
17. Which among the following is the exact ratio of guanine to cytosine in a DNA double helical structure?
18. Which of the following enzymes are used to transcript a portion of the DNA into mRNA?
a) RNA polymerase
b) DNA polymerase
c) Protein polymerase
19. Which is the correct complementary strand for AGAATTCGC?
20. Which of the following occurs in the process of central dogma reverse?
a) Conversion of a strand of mRNA to DNA
b) Changes in the chromosomal karyotype
c) Gene replication process
d) Protein production process
21. Which of the following ensures the stability of the helical structure of a DNA?
a) Presence of repetitive structures of a DNA code
b) Stacking of one base pair over the other
c) Presence of aneuploidy
d) Occurrence of chromosomal rearrangements
22. Which of the following is not a part of the nucleotide?
a) Phosphate group
b) Nitrogenous base
c) Pentose sugar
23. What will be the next step in the process of transcription?
DNA -> RNA ->?
Packaging of DNA Helix MCQ and Answers
24. What is the length of the DNA double helix, if the total number of bp (base pair) is 6.6 x 109?
a) 2.2 m/bp
b) 2.5 m/bp
c) 2.2 m
d) 2.5 m
25. What are the set of positively charged basic proteins called as?
26. What are the thread-like stained structures present in the nucleus known as?
27. How many bp are present in a typical nucleosome?
a) 200 bp
b) 100 bp
c) 300 bp
d) 90 bp
28. When the negatively charged DNA combines with the positively charged histone octamer, which of the following is formed?
29. How many nucleosomes are present in a mammalian cell?
a) 20 million
b) 30 million
c) 40 million
d) 10 million
30. Which of the following chromatins are said to be transcriptionally active and inactive respectively?
a) Euchromatin, Heterochromatin
b) Euchromatin, Prochromatin
c) Prochromatin, Euchromatin
d) Heterochromatin, Euchromatin
31. What are the additional set of proteins which are required for the packaging of chromatin at the higher levels known as?
a) Histone proteins
b) Non-Histone proteins
c) Histone chromosomal proteins
d) Non-Histone chromosomal proteins
32. What is the typical distance between two base pairs in nm?
a) 0.34 nm
b) 0.32 nm
c) 0.33 nm
d) 0.35 nm
The Search for Genetic Material MCQ and Answers
33. Which of the following bacterium is responsible for causing pneumonia?
a) Staphylococcus saprophyticus
b) Streptococcus pyogenes
c) Staphylococcus aureus
d) Streptococcus pneumoniae
34. When Streptococcus pneumoniae were cultured in a culture plate by Frederick Griffith, which among the following were produced?
a) Smooth colonies(S) and Rough colonies (R)
b) Shiny colonies (S) and Rough colonies (R)
c) Smooth colonies (S) and Rigorous colonies (R)
d) Silky colonies (S) and Rigorous colonies (R)
35. Which of the following is the wrong sequential order, when the S or the R strain of the bacterium is injected into the mice?
a) Mice -> S strain -> Dead
b) Mice -> R strain -> Alive
c) Mice -> Heat killed S strain -> Alive
d) Mice -> Heat killed S strain + live R strain -> Alive
36. Which of the following is responsible for transforming the R strain into the S strain?
a) Purified bio-chemicals from S-strain
b) Purified bio-chemicals from R-strain
c) Purified bio-chemicals from heat killed S-strain
d) Purified bio-chemicals from heat killed R-strain
37. Which of the following is responsible for the inhibition of transformation in organisms?
38. What will be the state of the mouse that has been injected with the heat killed S-strain from the Staphylococcus pneumoniae?
c) On the verge of dying
d) Lives with pneumonia
39. Which was considered to be as the genetic material prior to the works done by Oswald Avery, Colin MacLeod and Maclyn McCarty?
The Genetic Material is DNA MCQ and Answers
40. What are the viruses that affect bacteria known as?
41. Who proved that DNA was indeed the genetic material through experiments?
a) Alfred Hershey and Maclyn McCarty
b) Oswald Avery and Maclyn McCarty
c) Oswald Avery and Martha Chase
d) Alfred Hershey and Martha Chase
42. On which medium were the viruses cultivated by Alfred Hershey and Martha Chase?
a) A medium containing radioactive potassium (K)
b) A medium containing radioactive Uranium (U)
c) A medium containing radioactive phosphorous (P)
d) A medium containing potassium (K)
43. Which of the following is not a stage in the “Hershey-Chase experiment”?
44. Which of the following can be observed alongside with radioactive bacterium as a result of centrifugation?
a) Bacterium starts to produce RNA
b) Radioactivity can be detected in the supernatant
c) Bacterium starts to move slow
d) Radioactivity cannot be detected in the supernatant
45. What will happen when the radioactive protein capsule of the virus is attached onto the bacteria?
a) Radioactivity is detected in the supernatant
b) Radioactivity is absent in the supernatant
c) Radioactive DNA is injected into the bacterium
d) Attachment of the virus to the bacterium doesn’t occur
Properties of Genetic Material (DNA vs RNA) MCQ and Answers
46. Which of the following criterion needn’t be fulfilled by the genetic material?
a) Occurrence of replication
b) Should be able to express itself in the form of “Bohr’s characters”
c) Provision of scope for the mutation that is required for evolution
d) It should be chemically and structurally stable
47. Which of the following is not a characteristic of RNA?
a) It has ribose sugar molecules in the nucleotides
b) It is a single stranded molecule
c) It is not stable under alkaline conditions
d) All the 3 types of RNA are involved in protein synthesis
48. Which of the following criterion cannot be fulfilled by protein?
a) Formation of polypeptide chains
b) Generation of its replica
c) Formation of alpha helix and beta sheets
d) Non covalent bonds are present between amino acids
49. What will happen when the 2 complementary strands of the DNA are heated up and brought together?
a) They will repel each due to the charges formed
b) They will attract each other due to the charges formed
c) They will become non-complementary to each other
d) They will combine with each other under appropriate conditions
50. Which of the following statements is correct regarding DNA and RNA?
a) DNA is highly reactive
b) RNA is not catalytic
c) RNA cannot be easily degraded
d) DNA is a better genetic material than RNA
51. At what rate does the RNA mutate as compared to DNA?
a) Faster rate
b) Slower rate
c) Moderate rate
d) Depending on the medium
52. RNA codes are used for translation into which of the following?
53. Which of the following is responsible for the transmission of genetic information?
54. Which of the following is responsible for the storage of genetic material?
The Experimental Proof of Replication of DNA MCQ and Answers
55. Which process is termed as “semiconservative DNA replication”?
a) Presence of only newly synthesised strands in DNA
b) Presence of only parental strands in DNA
c) Presence of both parental and newly synthesised strands in DNA
d) Presence of a hybrid variety of strands
56. In which organism was the “Semiconservative theory of DNA replication” first observed?
a) Treponema pallidum
b) Vibrio cholerae
c) Staphylococcus pneumoniae
d) Escherichia coli
57. Which of the following is the heavy isotope of nitrogen?
58. Which organism was used to detect the presence of thymidine on the newly formed DNA in 1958?
a) Vivrio cholerae
b) Treponema pallidum
c) Vicia faba
d) Escherichia coli
The Machinery and the Enzymes for Replication of DNA MCQ and Answers
59. Which enzyme is used for the process of replication in E. Coli?
a) Restriction enzyme
b) Protease enzyme
c) Lipase enzyme
d) DNA polymerase
60. How long does it take for E. Coli to replicate?
a) 10 minutes
b) 20 minutes
c) 18 minutes
d) 21 minutes
61. What will happen if any abnormal changes or mistakes occur during the process of replication?
b) Normal cell growth
c) Unpredictable cell deaths
d) Rapid formation of new cells
62. In which type of process, can replication be seen at the small opening of the DNA?
d) Replication fork
63. In which direction do the DNA dependent DNA polymerases catalyse the polymerization reaction?
a) 3’ ? 5’
b) 5’ ? 3’
c) In both the directions
d) Is not direction dependent
64. In which phase of the cell cycle does the process of replication take place in E.coli?
a) The M phase
b) The G1 phase
c) The G2 phase
d) The S phase
65. What does the failure of cell division after DNA replication result in?
d) Migration of cells
Transcription Basics MCQ and Answers
66. What is the process of copying genetic information from a single strand of DNA into an RNA known as?
c) Reverse transcription
d) Reverse translation
67. Which of the following is not a transcription unit of the DNA?
d) Structural gene
68. In which direction does the DNA dependent RNA polymerase catalyse the polymerisation reaction?
a) 3’ ? 5’
c) Direction is dependent on the medium
d) 5’ ? 3’
69. Which of the following is the initial “start site“ for the process of transcription?
d) Structural gene
Transcription Unit and the Gene MCQ and Answers
70. What is a cistron?
a) A gene coding for RNA
b) A segment of DNA responsible for producing the nuclear coat
c) A segment of DNA coding for polypeptides
d) A gene coding for the template strand of DNA
71. Which of the following is monocistronic?
72. Which of the following is polycistronic?
Types of RNA and Process of Transcription in Prokaryotes MCQ and Answers
73. Which of the following is not a type of RNA?
74. What is the role of tRNA?
a) It provides the template strand
b) It brings the amino acids and reads the genetic code
c) It plays a catalytic role during translation
d) It plays a structural role during translation
75. Which of the following enzyme binds to the promoter and initiates the process of transcription?
a) DNA polymerase
c) RNA polymerase
76. What happens when the polymerase enzyme reaches the terminator region during transcription?
a) The nascent RNA falls off
b) The nascent DNA falls off
c) The nascent protein falls off
d) The nascent enzyme falls off
77. Which of the following stage is catalyzed by the RNA polymerase enzyme?
Process of Transcription in Eukaryotes MCQ and Answers
78. What is the role of RNA polymerase III?
a) Transcription of rRNAs
b) Transcription of mRNAs
c) Transcription of tRNAs
d) Transcription of hnRNA
79. What is the name of the process where the introns are removed and the exons are joined together in a defined order?
80. Which of the following types of RNA undergoes an additional process of capping and tailing during transcription?
81. Which of the following is the unusual nucleotide that is added to the 5’-end of the hnRNA during capping?
a) Methyl Guanosine Triphosphate
d) Adenosine Triphosphate
82. What is the approximate count of the total number of adenylate residues that are added to the 3’-end of the hnRNA during the process of tailing?
83. Which of the following process represents the domination of the RNA-world?
Genetic Code MCQ and Answers
84. Which of the following refers to a proposition which directs the sequence of amino acids during protein synthesis?
a) DNA fingerprinting
b) Genetic Code
85. How many bases are required for coding 20 amino acids?
86. How many codons code for an amino acid?
87. When is a codon said to be unambiguous?
a) When it codes for 2 amino acids
b) When it codes for 1 amino acids
c) When it codes for 3 amino acids
d) When it codes for 4 amino acids
tRNA-Adapter Molecule MCQ and Answers
88. Who came up with the idea of “adapter molecule”?
a) James Watson
b) Francis Crick
c) Gregor Mendel
d) Charles Darwin
89. Which of the following is an adapter molecule?
90. What does the anticodon loop of the tRNA contain?
a) A site for binding the amino acids
b) Bases that are complementary to the code
c) They have UAA codons
d) They have UAG codons
Translation MCQ and Answers
91. What is the process of polymerisation of polypeptides to amino acids known as?
c) Reverse transcription
d) Reverse translation
92. What is the process of activation of amino acids in the presence of ATP and its linkage to their cognate tRNA known as?
a) Charging of tRNA
b) Charging of ATP
c) Aminoacetylation of tRNA
d) Aminoacetylation of ATP
93. Which of the following cell organelle is responsible for the synthesis of proteins?
94. How many types of proteins are present inside a single ribosome?
95. What happens when the small subunit of the ribosome encounters an mRNA?
a) Separation of the small and the larger subunit of the ribosome
b) Translation of the central dogma of DNA
c) Joining of the small and the larger subunit of the ribosome
d) Transcription of the central dogma of DNA
96. Which of the following is the start codon?
97. Where are the untranslated regions (UTRs) present?
a) At both the 5’ and the 3’ ends
b) At only the 5’ end
c) At only the 3’ end
d) Outer to the 5’ and the 3’ end
Regulation of Gene Expression MCQ and Answers
98. In which of the following levels can gene expression not be exerted?
a) Transitional level
b) Transcriptional level
c) Reverse transcriptional level
d) Processing level
99. Regulatory protein can act both as an activator and a repressor.
Lac Operon MCQ and Answers
100. Which polycistronic structural gene is regulated by a common promoter and regulatory gene?
a) Trp operon
b) Lac operon
c) Ara operon
d) His operon
101. How many structural genes are present in a lac operon?
102. What does the structural gene (y) of a lac operon code for?
103. Which of the following is responsible for the switching on and off of the lac operon?
104. Which of the following is the necessary condition for the entry of lactose into the cell?
a) High level expression of lac operon
b) Low level expression of lac operon
c) Absence of lac operon in the cell
d) Absence of proteins in the cell
105. What is the regulation of a lac operon by a repressor known as?
a) Neutral regulation
b) Positive regulation
c) Mixed regulation
d) Negative regulation
Methodologies of HGP MCQ and Answers
106. Which of the following methodology is used to identify all the genes that are expressed as RNA in Human Genome Project (HGP)?
a) Sequence Annotation
b) Expressed Sequence Tags
107. Which of the following is a suitable host for the process of cloning in Human Genome Project (HGP)?
b) All types of fungi
108. Which of the following is a suitable vector for the process of cloning in Human Genome Project (HGP)?
a) PAC (Protozoal Artificial Chromosomes)
b) FAC (Fungal Artificial Chromosomes)
c) VAC (Viral Artificial Chromosomes)
d) YAC (Yeast Artificial Chromosomes)
109. Based on whose principle were the DNA molecules fragmented in the year 1977?
a) Maurice Wilkins
b) Rosalind Franklin
c) James Watson
d) Frederick Sanger
110. How are the genetic and the physical maps assigned on the genome?
a) Based on microsatellites
b) Based on macrosatellites
c) Based on kinetochores
d) Based on centromeres
Salient Features of HGP MCQ and Answers
101. How many nucleotides are present in the human genome?
a) 3164.7 million
b) 2015.9 million
c) 1982.0 million
d) 3247.9 million
102. Repeated sequence makes a large portion of the human genome.
DNA Fingerprinting MCQ and Answers
103. What are the differences in the specific regions of DNA sequence called during DNA finger printing?
a) Non repetitive DNA
b) Repetitive DNA
c) Satellite DNA
d) Histone DNA
104. What are the small peaks achieved by the repetitive DNA during the density gradient centrifugation process of DNA finger printing known as?
a) Non repetitive DNA
c) Satellite DNA
d) Histone DNA
105. How DNA can be as a useful tool in the forensic applications?
a) Showing the same degree of polymorphism with hair follicles
b) Showing different degrees of polymorphism with saliva
c) By not possessing any hereditable information
d) By the presence of lysozymes in it
106. How does polymorphism arise?
FAQs on Molecular Basis of Inheritance
Q: How are genes passed down from parent to child?
A: Genes are passed down from parent to child through DNA. DNA is the molecule that contains the genetic information of an organism. Every cell in the body contains DNA, and this DNA is passed down from generation to generation.
Q: How does DNA determine the traits of an organism?
A: DNA determines the traits of an organism by specifying the sequence of amino acids in proteins. Proteins are the molecules that carry out the functions of the cell. The sequence of amino acids in a protein is determined by the sequence of nucleotides in the DNA.
Q: How do mutations occur?
A: Mutations are changes in the DNA sequence. These changes can be caused by things like mistakes during cell division, exposure to radiation, or chemicals. Mutations can be harmful, neutral, or beneficial.
Q: What is genetic recombination?
A: Genetic recombination is the process by which different versions of a gene are shuffled between generations. This process can create new combinations of genes, which can lead to new traits.
Q: What is genetic drift?
A: Genetic drift is the random change in the frequency of a gene in a population. This can happen when a small group of individuals breaks off from a larger group and starts a new population.