For:- I.Sc (11th &12th ),B.Sc(Zoology Hons.

)
Add:- Shivmandir Road Babugaon, Hzb.825301
By:- Sunil Sir(M.Sc + B.ed) Mob.:-7004918039

1. Histone proteins are rich in

a. Histidine and arginine b. Histidine and lysine
c. Histidine , arginine and lysine d. Arginine and lysine
2. Histones proteins are
a. basic, negatively charged b. basic, positively charged
c. acidic, positively charged d. acidic, negatively charged
3. What does the given diagram represent?
a. nucleosome
b. spliceosome
c. histone complex
d. none
4. In DNA strand, the nucleotide are linked together by
a. glycosidic bonds b. phosphodiester bond c. peptide bond d. hydrogen bond
5. The ‘beads on string ‘ structure which seen under electron microscope are
a.Histone octamer b. Nucleosome c. Chromatid d.chromatin fibres
6. Which is the transcriptionally inactive chromatin?
a. Euchromatin b.Heterochromatin c. Loosely packed chromatine d. both b and c
7. Number of histone molecules in each nucleosome core is
a.14 b. 12 C. 10 D. 8
8. A + G = C + T is Applicable to
a. rRNA b.tRNA c.mRNA d.DNA
9. 5’ end of a polynucleotide chain contains
a. Hydroxyl group b. Ethyl group c. Carboxyl group d. phosphate group
10. A = T and G = C . The relationship of DNA is
a. Chargaff’s b. Le- chatelier’s principle c. coulomb’s law d. none
11. The two strands of DNA are held together by
a. peptide bonds b.phosphodiester bonds c. Hydrogen bonds d. S-S bonds
12. In double helix model of DNA , how far is each base pair from the next base pair
a.3.4nm b.0.34nm c.20nm d. 34nm

RNA Biology Classes, Near MultiGym Babugaon, By Sunil Sir 7004918039 Page 1
13. Nucleosome is
a. Intron interrupted DNA b. Double helix DNA
c. Negatively charged DNA wrapped around positively charged histone octamer
d. Satellite DNAs
14. Total number of ‘A and T’ in DNA is 45%. Amount of guanine will be
a. 22.5% b. 27.5% c.45% d . 55%
15. If a double stranded DNA has 20% of cytosine, what will be the percentage of adenine in it?
a. 20% b. 40% c. 30 % d. 60%

16. If the sequence of bases in one strand of DNA is ATGCATGCA, what would be the sequence
of bases on complementary strand?
a. ATGCATGCA b. AUGCAUGCA c. TACGTACGT d. UACGUACGU
17. Synthesis of DNA from RNA is explained by
a. transcription b. reverse transcription c. translation d. none
18. DNA double helix is
a. parallel b. antiparallel c. Without supercoils d. Always circular
19. Nucleotide pairs present in one turn of DNA helix are
a.20 b.8 c.10 d.9
20. In DNA nitrogen bases are joined to each other by
a. H-bonds b.peptide bonds c.Glycosidic bond d. phosphodiester bonds
21. DNA is acidic due to
a. Suger b. Purine c. phosphoric acid d. pyrimidine
22. Number of hydrogen bonds between A and T of DNA is
a. 4 b. 3 c.2 d.1
23. DNA and RNA differ by
a. Nitrogen bases and suger b. Nitrogen bases and phosphate groups
c. Number of C-atoms in suger d. Suger and phosphate groups
24. Nitrogenous base not found in DNA is
a.Cytosine b.Guanine c. Uracil D. Adenine
25. In AGCT of DNA , hydrogen bonds and base pairing occur between
a.A –G , C-T b.A – C, G –T c.A –T , C –G d.All of the above
26. Chargaff’s rules are applicable to
a. Single stranded RNA b. Single stranded DNA and RNA
c.Single stranded DNA d. Double stranded DNA
27. Information flow or central dogma of modern biology is
a.RNA –Proteins –DNA b.DNA –proteins –RNA
c. RNA –DNA – Proteins d. DNA –RNA –Proteins
28. Who proposed central dogma?
a.Wastson and Crick b.Beadle and Tatum c. Klug d. Crick
29. Who proved that DNA is basic genetic material?
a.Griffith/Avery et al b. Watson c.Boveri and Sutton d. Hershey and Chase
30. Ribosome act as a catalyst in the formation of
a.Glycosidic bond b.Phosphodiester bond c.Peptide bond d. All of these
31. Okazaki segments are formed during
a.Transduction b. Transcription c. Replication d.Translation
32. Okazaki fragments are formed in the direction of
a.3’ 5’ b.5’ 3’ c.5’ 5’ d.3’ 3’
33. Experimental material in the study of DNA replication has been
a.Escherichia coil b.Neurospora crassa c.pneumococcus d.Drosophila melanogaster

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34. Okazaki fragments are joined by
a.DNA polymerase lll b.DNA ligase c.DNA polymerase ll d.DNA polymerase l
35. Information transfer from RNA to DNA is
a.Transcription b. Translation c.Replication d.Revers transcription
36. Reverse transcriptase is
a.RNA dependent RNA polymerase b.DNA dependent RNA polymerase
c. DNA dependent DNA polymerase d. RNA dependent DNA polymerase
37. Methyl guanosine triphosphate is added at 5’ end of mRNA in a process of
a.Tailing b.Splicing c.Capping d.None of these
38. snRNA are transcribe with the help of
a. RNA polymeras l b. RNA polymerase l and ll c. RNA polymerase ll d. RNA polymerase lll
39. Capping is a process in which
a. Adenylate is added at 5’ end b. Methyl guanosine triphosphate is added at 5’end
c. Adenylate is added at 3’ end d. Methyl guanosine triphosphate is added at 3’end
40. Synthesis of RNA molecules is terminated by a single recognized by
a. Alpha factor b. Sigma factor c. Delta factor d. Rho factor
41. Split genes include
a. Exons b. Introns c. Pseudoalleles d. Both a and b
42. In split genes , the coding sequences are called
a. Exons b. Introns c. Cistrons d. Operons
43. Splicing is meant for elimination
a. Recons b. Mutons c. Exons d. Introns
44. RNA polymerase requires for initiation
a. Sigma factor b. Alpha subunit c. P-factor d. rho factor
45. The term gene was coined by
a. McClintock b. Morgan c. Johannsen d. De Duve
46. Enzyme required for transcription is
a. RNase b. Endonuclease c. RNA polymerase d. DNA polymerase
47. Hargobind Khorana is known for
a. Discovery of DNA b. Discovery of DNA ligase
c. Discovery of tRNA d. Discovery of genetic code
48. Out of 64 codons , 61 code for 20 types of amino acids . It is due
a. Unambiguous nature of code b. Degeneracy of genetic code
c. Wobbling of codons d. Universality of codons
49. The structure in chromatin seen as ‘bead-on string’ when viewed under electron microscope
are called
a. nucleotides b. nucleosides c. histone octamer d. nucleosomes
50. Find out the wrong statement about heterochromatin
a. densely packed b. stains dark c. transcriptionally active d. none
51. RNA is the genetic material in
a. prokaryotes b. eukaryotes c. TMV d. E.coli
52. Which one is not a termination codon?
a. UAA b. UAG c. AUG d. UGC
53. Three dimensional shape of tRNA is
a. Inverted L-shaped b. Clover leaf – likec. X- shaped d. Y-shaped
54. Lac operon is turned on when allolactose binds to
a. Operator gene b. Mrna c. Repressor protein d. Promoter site
55. In operon model, regulator gene function as
a. Repressor b. Regulator c. Inhibitor d. All of the above

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56. In lac-operon, repressor protein binds to
a. Regulator gene b. Operator gene c. Promoter gene d. Structural gene
57. Sequence of structural genes of lac operon is
a. y, z, a b. z, y, a c. a, y, z d. a, z, y
58. Haploid content of human DNA is
a. 1.65 x bp b. 3.3 x bp c. 4.6 x bp d. 3.3 x kbp
59. VNTRs refers to
a. Variable Number of Tandem Repeats b. Very Narrow Tandem Repeats
c. Variable Non – cistronic Transposon Repeats. d.Variable Non-cistronic Transposon Regions
60. Which is useful in solving parental disputes?
a. Hybridoma technology b. DNA Fingerprinting c. Western blotting d. ELISA
61. The first genetic material could be.
a. protein b.Carbohydrates c. DNA d. RNA
62. Name the enzyme that facilitates opening of DNA helix during transcription .
a. DNA helicase b. DNA polymerase c. RNA polymerase d. DNA ligase.
63. The term ‘Nuclein’ for the genetic material was used by
a. Meischer b. Chargaff c. Mendel d. Franklin
64. Purines found both in DNA and RNA are
a. Adenine and thymine b. Adenine and guanine
c. Guanine and cytosine d. Cytosine and thymine
65. The experimental proof for semiconservation replication of DNA was first shown in a;
a. Fungus b. Bacterium c. plant d. Virus
66. Which one of the following is not a part of a transcription unit in DNA?
a. The structural gene b. The inducer c. A terminator d. A promoter
67. Which one of the following is the starter codon?
a. AUG b. UGA c. UAA d. UAG
68. Which is not found in RNA?
a. Thymine b. Uracile c. Guanine d. Cytosine
69. The number of codons that code different amino acids is
a. 16 b. 31 c. 61 d. 64
70. Some amino acids are coded by more than one codon, hence the genetic code is
a. overlapping b. degenerate c. wobbled d. none
71. In a mRNA molecule, untranslated regions (UTRs) are present at
a. 5’-end (before start codon b. 3’-end (after stop codon)
c. both a and b d. 3’- end only
72. UTRs are the untranslated regions present on
a. rRNA b. tRNA c. mRNA d. hnRNA
73. In human, most number of genes are located on chromosome :
a. 1 b. 6 c. X d. Y

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 Previous Year Questions
2009
1. Describe the structure of polynucleotide of DNA.
Ans –
 A nucleotide is the basic unit of polynucleotide chain of DNA.
 Each nucleotide is composed of three components:
(i) a nitrogenous base
(ii) Deoxyribose sugar
(iii) a phosphate
 Nitrogenous base
 It is of two types: Purine(ex- Adenine and Guanine) and Pyrimidine (Cytosine and thymine)
 It attached with the sugar by help of N-glycosidic bond to form nucleoside.
 When phosphate attached with nucleoside by phosphoester bond, formed nucleotide.
 Two nucleotide are joined through phosphodiester bond and a dinucleotide is formed.
 Thus when numerous nucleotide are joined, a polynucleotide chain is formed.

2. Name the scientist who initially developed the technique of DNA-fingerprinting.

Ans – Alec Jeffreys in 1984.
2010
3. What is transcription? What is the product of transcription
Ans – The process of formation of RNA from DNA molecules is called transcriptions. The end
products of transcription is RNA.
2011
4. Which scientist first of all developed the technique of DNA fingerprinting?
Ans - Alec Jeffreys in 1984.

5. Describe the structure of polynucleotide’s of DNA.

Ans – see year 2009, Q. no. 1
2012
6. Describe the structure of DNA with the help of a diagram.
Ans –
 It is made of two polynucleotide chains.
 Backbone is formed by sugar-phosphate.
 Bases project inside, forming base pairs through hydrogen bond.

 The two chains of DNA have antiparallel polarity, 5′ 3′ in one and 3′ 5′ in other.
 Two chains are coiled in a right – handed fashion.

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  The length of one pitch of helix is 3.4nm (34Å).
 One turn contains 10 base pairs.
 The distance between two consecutive base pairs as 0.34nm.
 James Watson and Francis Crick proposed that DNA consist of two strands in 1953.

7. Describe the process of DNA replication.

Ans –
 Given by-Watson and Crick 1953.
 The mechanism by which exact copies of the genetic material are formed is known as
replication.
 The replication of DNA requires many enzymes and protein factor which are discussed below:-
 DNA dependent DNA polymerase- addition of deoxyribonucleotide.
 DNA Helicase - ATP dependent unwinding enzymes.
 both Strand DNA Binding Proteins (SSBPs) –Prevented from rewinding.
 Topoisomerase- Tension removing enzyme.
 DNA ligase- Connect two strand of DNA together by forming a bond.
 DNA dependent RNA polymerase or Primase – Synthesis of primer
 Mechanism of DNA replication:-
 The first important step in the replication is unwinding of double helix.
 Results formation of Y – shaped structure, called replication fork (Y fork).
 Single strand stabilised by the help of SSBP.
 Tension is release by the help of topoisomerase.
 The initiation of DNA synthesis requires a RNA primer (4-12 nucleotide).
 Initiation of replication occurs at 3′ end of the template.
 The primer grows in 5′ 3′ direction.
 In lagging strand, short segments of replicated DNA are called Okazaki fragment.
 The enzyme DNA polymerase adds the nucleotides complementary to the DNA template in
5′ 3′ direction in the presence of ATP.
 Leading strand- The enzymes synthesizes a new strand continuous stretch on 5′ 3′ strand,
this strand is called leading strand.
 Lagging strand- The second new strand called lagging strand. It is replication discontinuously
in short sections.

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 2013
8. Describe replication of DNA.
Ans – See year 2012 , Q. no. 7
9. In brief describe semi-conservative replication of DNA with the help of suitable diagram.
Ans –
 The replication where one of the two strands synthesized remain old and other become new is
called semi-conservative replication.
 Proposed by Watson and Crick in 1953.
 Given by Messelson and Stahl in 1958.
 Step of experiment:-
 They grow E. coli in a medium constituting 15NH4Cl over many generations.
 As a result, 15N was incorporated into newly synthesized DNA.
 Later they transfer E.coli from 15NH4Cl to 14NH4Cl medium.
 Multiplication of cells occurs.
 Samples were separated on CsCl through density gradient centrifugation.
Conclusion:-
 Sample no. 1 (after 20 minutes): DNA extracted that was hybrid.
 Sample no. 2 (after 40 minutes): DNA extracted that was composed of equal amount of
this hybrid and light DNA.

10. How did Hershey and Chase prove that DNA is genetic material?
Ans –
 Hershey and Chase (1952) worked on viruses
which infect bacteria called Bacteriophages.
 They grow some viruses on a medium that
contained radioactive phosphorus (32P) and
some others on the medium that contained
radioactive sulphur(35S)
(i) The viruses grown in the presence of
radioactive phosphorus (32P) contained
radioactive DNA not radioactive capsid,
because DNA contains phosphorus not capsid.
(ii) In the same way, the viruses grown in the
medium containing radioactive sulphur now
contained radioactive protein not radioactive
DNA. This is because DNA does not contain
sulphur(35S).
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 Experiment: -
 They allow virus to infect bacteria (E.coli).
 After the infection, the viral coats were removed from the bacteria with the help of blending
and centrifugation.
 Observation:- Bacteria which were infected by radioactive DNA virus were radioactive but the
other ones that were infect by radioactive protein viruses were non-radioactive.
 Conclusion : This indicates that only DNA not the protein coat entered the bacterial cell.
 Thus, genetic material that is passed from virus to bacteria is DNA.
2014
11. The mole percentage adanine in a double stranded DNA is 30. What will be mole percentage of
cytosine in the DNA.
a) 10 b) 20 c) 30 d) 60
12. Translation is the formation of
a) mRNA b) hormones c) Proteins d) tRNA
2015
13. Watson and Crick proposed the scheme for replication of DNA known as ?
a) Conservative DNA replication b) Transcription
c) Despersive DNA replication d) Semi-conservative DNA replication
14. What is the function of DNA Ligase?
Ans – DNA ligase act as a glue that joins two strand of DNA by forming phosphodiester bond.
15. Write the name of purine and pyrimidine bases in a DNA nucleotide.
Ans Purine – Adenine and Guanine
Pyrimidine – Cytosine, thymine and
2016

16. Write the main differences between DNA and RNA.

Ans
DNA RNA
It is double stranded. It is single stranded.
Sugar - Deoxyribose Sugar- Ribose
Nitrogenous base – A, G, C, T Nitrogenous base- A, G, C, U
It is stable genetic material. It is non unstable genetic material.
Obeys Chargaff’s rule. Not Obeys chargaff rule
Structure - Antiparallel and Helix Structure – hairpin and loops

17. Describe the structure of DNA with the help of diagram.

Ans - – See year 2012 , Q. no. 7
2017
18. Describe the different type of nucleic acids and write the differences between them.
Ans – there are two types of nucleic acids- DNA and RNA
DNA – It is a long polymer of deoxyribonucleotides. It is Double stranded helical structure.
RNA - It is the first Genetic material. It is single stranded structure.

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 DNA RNA
It is double stranded. It is single stranded.
Sugar - Deoxyribose Sugar- Ribose
Nitrogenous base – A, G, C, T Nitrogenous base- A, G, C, U
It is stable genetic material. It is non unstable genetic material.
Obeys Chargaff’s rule. Not Obeys chargaff rule
Structure - Antiparallel and Helix Structure – hairpin and loops

2018
19. What is the distance between two strands of DNA ?
a) 34 b) 20 c) 10 d) 9. 8 .
2019
20. Uracil is present in
(a) DNA (b) Protein (c) RNA (d) Sugar
2020
21. The process of formation of RNA from DNA is-
(a) Translation (b) Transamination (c) Replication (d) Transcription
22. Draw a well labeled diagram of DNA double helix.
2022
23. The ratio of dihybrid cross is-
(a) 3 : 1 (b) 9 : 3 : 3 : 1 (c) 9 : 7 (d) 12 : 3 : 1
24. A typical Nucleosome consists of-
(a) 50 bp of DNA helix (b) 100bp of DNA helix
(c) 150 bp of DNA helix (d) 200 bp of DNA helix
25. In a DNA molecule hydrogen bond is present between-
(a) Two nucleotides (b) Ribose sugar and phosphate molecule
(c) Nitrogenous bases (d) Ribose sugar and nitrogenous base
26. Which mendelian principle is also known as 'Law of Purity of Gametes'?
(a) Law of Dominance (b) Law of Segregation
(c) Law of Independent Assortment (d) Chromosomal Theory of Inheritance
27. Which of the following is genetic material?
(a) RNA (b) DNA (c) Protein (d) Both a & b
28. Which of the following is an initiation codon?
(a) UUU (b) AUA (c) AUG (d) UAG
29. The function of Helicase during the process of replication is-
(a) Joining of DNA fragments (b) Unwinding of DNA strands
(c) Polymerization of nucleotides (d) Formation of primer segments
30. The coding sequence of mRNA is called as-
(a) Intron (b) Cistron (c) Positron (d) Exon
2023
31. In which phase of the cell division does DNA replication take place?
Ans – S – phase.

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32. The phenotypic ratio for a dihybrid cross is
a. 1:2:1 b. 3:1 c. 9:4 d. 9:3:3:1
33. The process by which RNA is formed from DNA is called
a. Replication b. Transcription c. Translation d. Linkage
34. Which nitrogenous base is not present in a DNA molecules?
a. Adenine b. Guanine c. Cytosine d. Uracil
35. Explain the process of DNA replication with the help of suitable diagrams.
2024
36. Number of base pairs in haploid set of DNA of human is
a. 3.3 x 109 b. 6.6 x 109 c. 4.6 x 109 d. 9.9 x 109
37. The technique of DNA fingerprinting was initially developed by
a. G.J.Mendel b. Alec-jeffreys c. Francois Jacob d. Jacques monod
38. At which position, in RNA in every nucleotide residue an additional = OH group is present in
the ribose?
a. 5’position b.3’ position c. 2’ position d. 4’ position
39. For initiation of protein synthesis ribosome binds to the …………. Codon of mRNA
a. AUG b. UGA c. AGU d. UAG
40. The sequence of nucleotide in the template strand of a DNA is 3’ATGCATGCATGC 5’. What
will be the sequence of nucleotide in the messenger RNA?
a. 5’ ATGCATGCATGC 3’ b. 5’ AUGCAUGCAUGC 3’
c. 5’ TUCGTUCGUACG 3’ d. 5’ UACGUACGUACG 3’
41. What is central dogma?
Ans – The central dogma of molecular biology is a theory that state that genetic information flows
only in one direction, from DNA to RNA to Protein.
42. What is the different between RNA and DNA?
Ans – See year 2016, Q. 16

Extra questions
43.Write the different between Purine and Pyrimidine

Purine Pyrimidine
Purines are large-sized nitrogen containing Pyrimidines are small-sized nitrogen containing
biomolecules. biomolecules.
It is a double ring. It is a single ring.
Purines bases are of two types adenine and Pyrimidine bases are of three types- cytosine,
guanine. thymine and Uracil.
Catabolism produces uric acid Catabolism produces carbon dioxide, ammonia
and beta amino acids.
44. Why hnRNA is required to undergo splicing?
ans – hnRNA is required to undergo splicing because it contains both coding exon and non-coding
Intron. Hence, the non-coding Introns need to be remove for the continuity of the process.

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45.Write the different between Prokaryotic DNA and eukaryotic DNA

Prokaryotic DNA Eukaryotic DNA

Found in cytoplasm, mitochondria and plastids. It is found in nucleus.
It is usually circular. It is usually linear.
It is naked, without histone. It is wrapped over histone.
G:C contents are more than A:T. A:T contents are more than G:C

46. Write the different between Euchromatin and Heterochromatin

Euchromatin Heterochromatin
It stains lightly It stains darkly.
This chromatin is loosely packed This chromatin is more densely packed.
It is transcriptionally active. It is transcriptionally inactive.
During replication, it takes less time to unwind. It takes longer time to unwind.

47.Write the different between Leading strand and Lagging strand.

Leading strand Lagging strand

It does not require DNA ligase for its growth. It require DNA ligase for joining Okazaki
fragments.
Only a single RNA primer is required. Starting of each Okazaki fragment requires a
new RNA.
Formation of leading strand is quite rapid. Formation of lagging strand is slower.
Template opens in 3’ 5’ Template opens in 5’ 3’ direction.

48.Write the different between Replication and transcription.

Replication Transcription
It is synthesis of DNA from DNA. It is synthesis of RNA from DNA.
Both the strands take part in replication. Only one strand functions as template.
It produces double stranded replicas DNA. It form single stranded RANs.
RNA primer is essential for initiation. A primer is not required.

49.Write the different between transcription and translation.

Transcription Translation
It is formation of RNA from DNA. It is formation of protein from RNA.
It occurs inside the nucleus in eukaryotes. It occurs in cytoplasm.
Polymerase move over the template. Ribosome moves over mRNA.
Product often requires splicing. Splicing is absent.

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