Q1. Frederick Griffith conducted his 'Transforming Principle' experiments using:
Correct Answer: (b)
Page 84: In 1928, Frederick Griffith... experiments with Streptococcus pneumoniae.
Q2. The largest known human gene is:
Correct Answer: (c)
Page 104: The largest known human gene being dystrophin at 2.4 million bases.
Q3. Match the codon features:
Column-I
Column-II
A. Degenerate
(I) Same codon from bacteria to human
B. Universal
(II) More than one codon for one amino acid
C. Stop codons
(III) UAA, UAG, UGA
D. Initiator codon
(IV) AUG
Correct Answer: (a)
Genetic code features (Page 96).
Q4. In the Hershey-Chase experiment, viruses grown on radioactive Phosphorus contained:
Correct Answer: (b)
Page 85: Viruses grown in the presence of radioactive phosphorus contained radioactive DNA.
Q5. Regarding 'HGP' goals: (i) identify all 20,000-25,000 genes. (ii) Determine sequence of 3 billion base pairs. (iii) Address ELSI (Ethical, Legal, Social Issues).
Correct Answer: (a)
Section 5.9 list of goals.
Q6. The length of DNA double helix in a typical mammalian cell is approximately:
Correct Answer: (b)
Page 83: It comes out to be approximately 2.2 metres.
Q7. Which of the following is being described? (i) It is the regulatory gene of lac operon. (ii) Expressed constitutively (all-the-time). (iii) Produces a protein that binds to operator.
Correct Answer: (c)
Description of the repressor gene (Page 100-101).
Q8. Identify the correct phylum/group being described? (i) It is the flow from RNA to DNA. (ii) Occurs in some viruses. (iii) Reverse of the Central Dogma.
Correct Answer: (c)
Page 83 mentions information flow from RNA to DNA.
Q9. In a transcription unit, the strand with 3' -> 5' polarity is called:
Correct Answer: (b)
Page 92: The strand that has the polarity 3' -> 5' acts as a template.
Q10. Which of the following is used as a probe in DNA Fingerprinting?
Correct Answer: (c)
Page 106: He used a satellite DNA as probe... It was called as Variable Number of Tandem Repeats (VNTR).
Q11. Identify the correct phylum/group being described? (i) They are small nuclear RNAs. (ii) Transcribed by RNA Polymerase III. (iii) Part of eukaryotic transcription complexity.
Correct Answer: (c)
Section 5.5.3 lists snRNAs as products of Pol III.
Q12. Assertion: DNA is a better genetic material than RNA.
Reason: DNA is chemically less reactive and structurally more stable than RNA.
Correct Answer: (a)
Page 87 explains that stability is a key criteria for genetic material.
Q13. The pitch of the DNA double helix is:
Correct Answer: (b)
Page 81: The pitch of the helix is 3.4 nm.
Q14. Assertion: Translation is energetically an expensive process.
Reason: Amino acids are activated in the presence of ATP before joining.
Correct Answer: (a)
Section 5.7: Charging of tRNA requires ATP energy.
Q15. According to Chargaff's rule, for a double-stranded DNA, the ratio of Adenine to Thymine and Guanine to Cytosine is:
Correct Answer: (b)
Page 81: Ratios between Adenine and Thymine and Guanine and Cytosine are constant and equals one.
Q16. Which are correct for 'Human Genome' features? (i) 3164.7 million bp. (ii) 99.9% bases are same in all humans. (iii) Average gene has 3000 bases.
Correct Answer: (a)
Salient features of HGP (Page 104).
Q17. Assertion: The structural gene in eukaryotes is monocistronic.
Reason: They have interrupted coding sequences (exons and introns).
Correct Answer: (a)
Being monocistronic refers to coding for one polypeptide; having introns is a structural feature (Page 93).
Q18. The length of DNA in a bacteriophage known as φ × 174 is:
Correct Answer: (b)
Page 80: For example, a bacteriophage known as φ × 174 has 5386 nucleotides.
Q19. Assertion: The genetic code is degenerate.
Reason: Some amino acids are coded by more than one codon.
Correct Answer: (a)
Standard definition of degeneracy (Page 96).
Q20. Match the DNA structure features:
Column-I
Column-II
A. Purine
(I) Adenine, Guanine
B. Pyrimidine
(II) Cytosine, Thymine, Uracil
C. DNA Back-bone
(III) Sugar and Phosphate
D. Stability
(IV) Stacking of base pairs
Correct Answer: (a)
Chemical structure of DNA (Page 80-82).
Q21. Correct statements for 'DNA Packaging': (i) DNA is negatively charged. (ii) Histones are positively charged proteins. (iii) chromatin fibres are condensed at metaphase.
Correct Answer: (a)
Summary of Section 5.1.2.
Q22. Assertion: Chromosome 1 was the last human chromosome to be sequenced.
Reason: Its sequence was completed only in May 2006.
Correct Answer: (a)
Section 5.9: Sequence of chromosome 1 was completed last.
Q23. Identify true statements for 'Deoxyribonucleoside triphosphates': (i) Act as substrates for replication. (ii) Provide energy for polymerisation. (iii) Have high-energy phosphates.
Correct Answer: (a)
Dual role in replication (Page 90).
Q24. Match the Following for RNA types:
Column-I
Column-II
A. mRNA
(I) Adapter molecule
B. tRNA
(II) Provides template
C. rRNA
(III) Catalyst in translation
Correct Answer: (a)
Section 5.5.3 and 5.7.
Q25. The technique of DNA Fingerprinting was initially developed by:
Correct Answer: (a)
Page 106: The technique of DNA Fingerprinting was initially developed by Alec Jeffreys.
Q26. Identify the correct steps of DNA Fingerprinting technique: (i) Isolation of DNA. (ii) Digestion by restriction endonucleases. (iii) Separation by electrophoresis. (iv) Blotting to synthetic membranes.
Correct Answer: (a)
Section 5.10 lists these steps (i to vi) in order.
Q27. Regarding 'Hershey and Chase' experiment: (i) Used bacteriophages. (ii) Radioactive 35S was used for protein. (iii) Radioactive 32P was used for DNA.
Correct Answer: (a)
Mechanism of the experiment (Page 85).
Q28. Assertion: DNA polymerase catalyse polymerisation only in one direction (5'->3').
Reason: This creates a replication fork at the origin.
Correct Answer: (a)
DNA polymerase directionality is correct, but it causes continuous/discontinuous synthesis, not the fork itself (Page 90).
Q29. Identify correct features of the 'Genetic Code': (i) It is nearly universal. (ii) It is read in a contiguous fashion. (iii) One codon codes for only one amino acid (unambiguous).
Correct Answer: (a)
Section 5.6 salient features.
Q30. Which of the following is correct? (i) S. pneumoniae has S and R strains. (ii) S strain has a polysaccharide coat. (iii) Transformation was due to DNA transfer.
Correct Answer: (a)
Summary of Griffith and Avery's work.
Q31. Assertion: tRNA is called an adapter molecule.
Reason: It reads the code on mRNA and binds to specific amino acids.
Correct Answer: (a)
Section 5.6.2 defines its dual role as an adapter.
Q32. Which are true for 'Euchromatin'? (i) Loosely packed. (ii) Stains light. (iii) Transcriptionally active.
Correct Answer: (a)
Section 5.1.2 description.
Q33. Assertion: DNA replication is semiconservative.
Reason: After replication, each DNA molecule has one parental and one newly synthesised strand.
Q34. Identify the correct statements regarding RNA world: (i) RNA was the first genetic material. (ii) RNA used to act as a catalyst. (iii) DNA evolved from RNA with chemical modifications.
Correct Answer: (a)
Section 5.3 summarizes the primacy of RNA.
Q35. Regarding 'Transcription' vs 'Replication': (i) Total DNA duplicated in replication. (ii) Only a segment of DNA copied in transcription. (iii) Complementarity governs both.
Correct Answer: (a)
Fundamental comparison from Section 5.5.
Q36. Which statements about 'Lac Operon' are correct? (i) Elucidated by Jacob and Monod. (ii) Lactose is the inducer. (iii) Repressor binds to operator in absence of inducer. (iv) Regulation by repressor is positive regulation.
Correct Answer: (a)
Regulation by repressor is negative regulation (Page 101).
Q37. Which are correct for 'Genetic Mapping' tools? (i) Information on polymorphism of restriction sites. (ii) microsatellites. (iii) sequencing of whole genomes.
Correct Answer: (a)
Methods used in HGP (Page 104-105).
Q38. Assertion: The genetic code is nearly universal.
Reason: Exceptions have been found in mitochondrial codons.
Correct Answer: (a)
The universality is a general rule; mitochondrial exceptions are rare (Page 96).
Q39. A typical nucleosome contains how many base pairs of DNA helix?
Correct Answer: (b)
Page 83: A typical nucleosome contains 200 bp of DNA helix.
Q40. Unequivocal proof that DNA is the genetic material came from the experiments of:
Correct Answer: (b)
Page 85: The unequivocal proof that DNA is the genetic material came from the experiments of Alfred Hershey and Martha Chase (1952).
Q41. Regarding the 'Structure of Proteins' (Biologist's view): (i) Biologists describe structure at 4 levels. (ii) Primary is the sequence of amino acids. (iii) Tertiary is a hollow woolen ball-like fold.
Correct Answer: (a)
Section 5.7/9.7 protein structure info.
Q42. Correct statements about 'DNA Polymerase' accuracy: (i) Must be fast. (ii) Must be highly accurate. (iii) Mistakes result in mutations.
Correct Answer: (a)
Enzymatic properties from Section 5.4.2.
Q43. Assertion: Repetitive DNA sequences have no direct coding functions.
Reason: They are used as markers in DNA fingerprinting.
Correct Answer: (a)
While both are true, being used as markers isn't the reason why they don't code for proteins (Page 104).
Q44. Sickle cell anemia is caused by a point mutation in the beta globin chain resulting in the change of ______ to ______.
Correct Answer: (b)
Page 97: Point mutation... results in the change of amino acid residue glutamate to valine.
Q45. Assertion: Heterochromatin is transcriptionally inactive.
Reason: It is densely packed and stains dark.
Q46. Which of the following is the first genetic material?
Correct Answer: (b)
Page 88: RNA was the first genetic material.
Q47. Assertion: RNA was the first genetic material.
Reason: Essential life processes such as metabolism and splicing evolved around RNA.
Correct Answer: (a)
Page 88: RNA world hypothesis.
Q48. Which are correct for 'Mutations' as per the text? (i) Frameshift mutations insert or delete one/two bases. (ii) Sickle cell anemia is a point mutation. (iii) Chromosomal aberrations are common in cancer cells.
Correct Answer: (a)
Section 5.6.1.
Q49. The average rate of polymerisation by DNA polymerase in E. coli is approximately:
Correct Answer: (c)
Page 90: The average rate of polymerisation has to be approximately 2000 bp per second.
Q50. Histones are rich in basic amino acid residues such as:
Correct Answer: (b)
Page 83: Histones are rich in the basic amino acid residues lysine and arginine.
Q51. Assertion: In eukaryotes, transcription and translation can be coupled.
Reason: Transcription and translation take place in the same compartment in eukaryotes.
Correct Answer: (b)
Coupling occurs in bacteria (prokaryotes) because they have no nuclear membrane. In eukaryotes, they are separated by space (Page 94).
Q52. The transcriptionally active, loosely packed chromatin is called:
Correct Answer: (c)
Page 84: Euchromatin is said to be transcriptionally active chromatin.
Q53. The nitrogenous base Uracil is found in RNA at the place of:
Correct Answer: (d)
Page 80: Uracil is present in RNA at the place of Thymine.
Q54. Correct statements for 'RNA Splicing' complexity: (i) Representative of ancient feature of genome. (ii) reminiscent of antiquity. (iii) Dominance of RNA-world.
Correct Answer: (a)
Evolutionary significance mentioned on Page 95.
Q55. In the lac operon, the i gene codes for:
Correct Answer: (b)
Page 100: The i gene codes for the repressor of the lac operon.
Q56. Which of the following are salient features of the genetic code? (i) The codon is triplet. (ii) 61 codons code for amino acids. (iii) UAA, UAG, UGA are stop codons. (iv) Code is ambiguous and specific.
Correct Answer: (a)
The code is unambiguous and specific (Page 96).
Q57. In the Meselson-Stahl experiment, the heavy isotope used was:
Correct Answer: (c)
Page 89: They grew E. coli in a medium containing 15NH4Cl (15N is the heavy isotope of nitrogen).
Q58. Regarding 'Replication Fork', identify correct facts: (i) Replication is continuous on 3' -> 5' template. (ii) Replication is discontinuous on 5' -> 3' template. (iii) DNA dependent DNA polymerase catalyse only in 5' -> 3' direction.
Correct Answer: (a)
Section 5.4.2 explains the mechanics of the fork.
Q59. Which is true for 'VNTR'? (i) Belongs to mini-satellite DNA. (ii) Size varies from 0.1 to 20 kb. (iii) Copy number varies from chromosome to chromosome.
Correct Answer: (a)
Section 5.10 description of VNTRs.
Q60. Match the scientists with their contributions:
Column-I
Column-II
A. Frederick Griffith
(I) Biochemical nature of transforming principle
B. Avery, MacLeod, McCarty
(II) Semiconservative replication proof
C. Meselson and Stahl
(III) Transforming Principle
D. Alec Jeffreys
(IV) DNA Fingerprinting
Correct Answer: (a)
Historical milestones in molecular biology.
Q61. Which are correct for 'mRNA' translation? (i) read in combination of three (codons). (ii) Translation occurs in ribosomes. (iii) Site of protein synthesis.
Correct Answer: (a)
Process of translation (Page 99).
Q62. Match the DNA lengths in Column-I with the corresponding organisms in Column-II:
Column-I (DNA Length)
Column-II (Organism)
A. 5386 nucleotides
(I) Human (Haploid)
B. 48502 base pairs
(II) Bacteriophage φ × 174
C. 4.6 × 10^6 bp
(III) Bacteriophage Lambda
D. 3.3 × 10^9 bp
(IV) E. coli
Correct Answer: (a)
Data from Page 80.
Q63. Which chromosome has the most genes (2968)?
Correct Answer: (b)
Page 104: Chromosome 1 has most genes (2968).
Q64. The experimental proof for semiconservative replication of DNA was first shown in:
Correct Answer: (c)
Page 88: It was shown first in Escherichia coli.
Q65. Identify the correct phylum/group being described? (i) They are polymers of nucleotides. (ii) Deoxyribonucleic acid and Ribonucleic acid are two types. (iii) They are the genetic material of living systems.
Q66. Assertion: DNA polymorphism is the basis of DNA fingerprinting.
Reason: Polymorphism arises due to mutations which accumulate in non-coding DNA.
Correct Answer: (a)
Section 5.10 explains how mutations in repetitive DNA create individual-specific patterns.
Q67. Regarding 'Satellite DNA' in fingerprinting: (i) Form small peaks in density centrifugation. (ii) Categorized into micro and mini satellites. (iii) High degree of polymorphism.
Correct Answer: (a)
Section 5.10 description.
Q68. Regarding 'Translation', identify true statements: (i) Polymerisation of amino acids to form polypeptide. (ii) Ribosome acts as a catalyst. (iii) UTRs are required for efficient translation.
Correct Answer: (a)
Summary of Section 5.7.
Q69. Identify the correct features of the DNA double helix: (i) Back-bone is made of sugar and phosphate. (ii) Two chains have anti-parallel polarity. (iii) The pitch is 3.4 nm. (iv) Coiled in a left-handed fashion.
Correct Answer: (a)
DNA is coiled in a right-handed fashion (Page 81).
Q70. Match the following for HGP facts:
Column-I
Column-II
A. Human genome size
(I) 3164.7 million bp
B. Genome coding for proteins
(II) Less than 2 per cent
C. Chromosome 1 genes
(III) 2968
D. Chromosome Y genes
(IV) 231
Correct Answer: (a)
Salient features of human genome (Page 104).
Q71. Identify correct facts for 'SNPs': (i) Single nucleotide polymorphism. (ii) 1.4 million locations in human DNA. (iii) Used for tracing human history.
Correct Answer: (a)
Salient features of human genome (Page 104).
Q72. The process of removing introns and joining exons in a defined order is:
Correct Answer: (c)
Page 95: Subjected to a process called splicing where the introns are removed and exons are joined.
Q73. Which of the following is correct regarding 'The DNA' as described in the text? (i) Length is usually defined as number of nucleotides. (ii) E. coli has 4.6 × 10^6 bp. (iii) Haploid human DNA is 3.3 × 10^9 bp. (iv) λ bacteriophage has 5386 nucleotides.
Correct Answer: (a)
λ bacteriophage has 48502 bp; φ × 174 has 5386 nucleotides (Page 80).
Q74. Regarding the Meselson-Stahl experiment, which statements are true? (i) 15N is a radioactive isotope. (ii) CsCl density gradient was used for separation. (iii) E. coli divides in 20 minutes. (iv) After 40 minutes, DNA was composed of equal amounts of hybrid and light DNA.
Correct Answer: (a)
15N is a heavy isotope, not radioactive (Page 89).
Q75. Assertion: 2'-OH group in RNA makes it easily degradable.
Reason: DNA lacks this hydroxyl group at 2' position of the sugar.
Correct Answer: (a)
Page 87: The presence of 2'-OH makes RNA labile and degradable, while its absence in DNA adds stability.
Q76. Regarding 'Polynucleotide chain': (i) 5'-end has a free phosphate group. (ii) 3'-end has a free OH group. (iii) Sequence of bases read from 5' to 3'.
Q77. The codon AUG has dual functions; it codes for Methionine and acts as:
Correct Answer: (b)
Page 96: AUG has dual functions. It codes for Methionine (met), and it also acts as initiator codon.
Q78. Match the enzymes in Column-I with their functions in Column-II:
Column-I (Enzyme)
Column-II (Function)
A. DNA Polymerase
(I) Joining Okazaki fragments
B. DNA Ligase
(II) Synthesis of DNA strand
C. RNA Polymerase I
(III) Transcribes snRNAs
D. RNA Polymerase III
(IV) Transcribes rRNAs
Correct Answer: (a)
Based on Section 5.4.2 and 5.5.3.
Q79. Which linkage joins a nitrogenous base to the 1' C of a pentose sugar?
Correct Answer: (b)
Page 80: A nitrogenous base is linked to the OH of 1' C pentose sugar through a N-glycosidic linkage.
Q80. Correct statements for 'Eukaryotic Transcription' include: (i) RNA Polymerase I transcribes rRNAs. (ii) RNA Polymerase II transcribes hnRNA. (iii) RNA Polymerase III transcribes tRNA and 5srRNA.
Correct Answer: (a)
Section 5.5.3 (Page 94-95).
Q81. Regarding 'Transcription Unit', identify the correct statements: (i) Promoter is located towards 5' -end (upstream) of coding strand. (ii) Terminator is towards 3' -end (downstream) of coding strand. (iii) Structural gene is flanked by promoter and terminator.
Correct Answer: (a)
Standard definitions from Section 5.5.1 (Page 92).
Q82. Match the following for DNA replication:
Column-I
Column-II
A. 3' -> 5' template
(I) Discontinuous synthesis
B. 5' -> 3' template
(II) Continuous synthesis
Correct Answer: (a)
Page 90: On one strand (3'->5' template) replication is continuous... on the other (5'->3' template) it is discontinuous.
Q83. Which of the following is correct? (i) George Gamow proposed triplet code. (ii) Har Gobind Khorana synthesised RNA homopolymers. (iii) Severo Ochoa enzyme is polynucleotide phosphorylase.
Correct Answer: (a)
History of deciphering the genetic code (Page 95-96).
Q84. Identify correct features of 'Avery, MacLeod and McCarty' work: (i) Worked on transforming principle. (ii) Used DNase to inhibit transformation. (iii) Proved DNA is the transforming substance.
Q85. Which are correct regarding 'Capping and Tailing'? (i) Capping adds methyl guanosine triphosphate to 5'-end. (ii) Tailing adds adenylate residues to 3'-end. (iii) Occurs in hnRNA.
Correct Answer: (a)
Processing of eukaryotic RNA (Page 95).
Q86. Which statements about 'DNA Fingerprinting' are correct? (i) Involves identifying repetitive DNA. (ii) Satellite DNA shows high degree of polymorphism. (iii) Alec Jeffreys developed the technique using VNTR. (iv) It is the basis of paternity testing.
Correct Answer: (a)
Comprehensive summary of Section 5.10.
Q87. Assertion: Human Genome Project (HGP) was called a mega project.
Reason: It required 13 years and approximately 9 billion US dollars.
Correct Answer: (a)
Magnitude of cost and time defines it as a mega project (Page 102).
Q88. Match the following for DNA packaging:
Column-I
Column-II
A. Histone octamer
(I) 200 bp of DNA
B. Nucleosome
(II) 8 histone molecules
C. Euchromatin
(III) Densely packed, inactive
D. Heterochromatin
(IV) Loosely packed, active
Correct Answer: (a)
Based on Section 5.1.2.
Q89. Regarding 'HGP', which salient features are true? (i) Total number of genes is estimated at 30,000. (ii) Less than 2% of genome codes for proteins. (iii) Functions are unknown for over 50% of discovered genes. (iv) 99.9% nucleotide bases are same in all humans.
Correct Answer: (a)
Page 104 lists these as salient observations.
Q90. Assertion: Lac operon is under negative regulation.
Reason: The repressor protein binds to the operator to prevent transcription.
Correct Answer: (a)
Section 5.8.1 clarifies that regulation by repressor is negative regulation.
Q91. Assertion: Adenine pairs with Thymine with three H-bonds.
Reason: Guanine pairs with Cytosine with two H-bonds.
Correct Answer: (a)
A=T has 2 bonds; G≡C has 3 bonds (Page 81).
Q92. Match the following for the lac operon:
Column-I (Gene)
Column-II (Product)
A. i gene
(I) Permease
B. z gene
(II) Repressor
C. y gene
(III) Transacetylase
D. a gene
(IV) Beta-galactosidase
Correct Answer: (a)
Section 5.8.1: The Lac operon.
Q93. In eukaryotes, the monocistronic structural genes have interrupted coding sequences called:
Correct Answer: (b)
Page 93: The coding sequences or expressed sequences are defined as exons.
Q94. DNA was first identified as an acidic substance 'Nuclein' in 1869 by:
Correct Answer: (c)
Page 81: DNA as an acidic substance present in nucleus was first identified by Friedrich Meischer in 1869.
Q95. Assertion: The distance between two polynucleotide chains in DNA remains almost constant.
Reason: A purine always comes opposite to a pyrimidine in base pairing.
Q96. The enzyme used to join discontinuously synthesised fragments (Okazaki fragments) is:
Correct Answer: (c)
Page 90: The discontinuously synthesised fragments are later joined by the enzyme DNA ligase.
Q97. Which bacteria produced smooth shiny colonies (S) in Griffith's experiment?
Correct Answer: (b)
Page 84: The S strain bacteria have a mucous (polysaccharide) coat.
Q98. Which are correct for 'tRNA'? (i) Called adapter molecule. (ii) Has an anticodon loop. (iii) Has an amino acid acceptor end. (iv) Looks like an inverted L in actual structure.
Correct Answer: (a)
Full description from Section 5.6.2 (Page 98).
Q99. Assertion: Splicing is an essential step in eukaryotic transcription.
Reason: Primary transcripts in eukaryotes contain non-functional introns.
Correct Answer: (a)
Introns must be removed to make a functional mRNA (Page 95).
Q100. In the Central Dogma, genetic information flows from:
Correct Answer: (b)
Page 82: Francis Crick proposed the Central dogma... genetic information flows from DNA -> RNA -> Protein.
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