Topic 1: THE DNA
Q 1: DNA and RNA are the polymer of
✅ Nucleotides
Q 2: The length of DNA is usually defined as number of ……………. present in it.
✅ Nucleotides
Q 3: Ф 174 (a bacteriophage) has …….. nucleotides.
✅ 5386
Q 4: Bacteriophage lambda has ……… base pairs (bp).
✅ 48502
Q 5: Number of base pairs in E. coli DNA is
✅ 4.6x106 bp
Q 6: Haploid content of human DNA is
✅ 3.3x109 bp
Q 7: A nucleotide has 3 components such as a nitrogenous base, a pentose sugar and a ………..
✅ Phosphate group
Q 8: The pentose sugar present in DNA is deoxyribose whereas in RNA is ………….
✅ Ribose
Q 9: Adenine (A) and Guanine (G) are the nitrogen bases that belongs to
✅ Purines
Q 10: Pyrimidines are a group of nitrogen bases that includes Cytosine (C), Thymine (T) and ………..
✅ Uracil (U)
Q 11: The nitrogen base present in RNA instead of thymine is
✅ Uracil
Q 12: Thymine is also called
✅ 5-methyl Uracil
Q 13: A nitrogenous base is linked to the OH of 1' C pentose sugar through an …………. to form nucleoside.
✅ N-glycosidic linkage
Q 14: A phosphate group is linked to OH of 5' C of a nucleoside through ………….. to form nucleotide.
✅ Phosphoester linkage
Q 15: In RNA, each nucleotide has an additional ………… at 2' C of the ribose.
✅ –OH group
Q 16: 2 nucleotides are linked through 3’-5’ phosphodiester bond to form
✅ Dinucleotide
Q 17: When more nucleotides are linked, it forms ………..
✅ Polynucleotide
Q 18: Who first identified DNA and named it Nuclein?
✅ Friedrich Miescher
Q 19: Double helix model of DNA was proposed by
✅ James Watson & Francis Crick
Q 20: Double helix model of DNA was based on X-ray diffraction data produced by
✅ Maurice Wilkins & Rosalind Franklin
Q 21: DNA is made of 2 ……………. chains coiled in a right-handed fashion.
✅ Polynucleotide
Q 22: Backbone of DNA is formed of sugar and ………….
✅ Phosphates
Q 23: In DNA, one chain has the polarity 5’→3’ and the other has 3’→5’. This arrangement is called
✅ Anti-parallel polarity
Q 24: The bases in 2 DNA strands are paired through
✅ H-bonds
Q 25: Adenine pairs with Thymine through 2 hydrogen bonds whereas cytosine pairs with guanine through ……….
✅ 3 hydrogen bonds
Q 26: In DNA, the ratio of A to T and the ratio of G to C are equal. This is called
✅ Erwin Chargaff’s rule
Q 27: Pitch of DNA helix is about …………
✅ 3.4 nm (34 Å)
Q 28: Number of base pairs in each turn of the DNA helix is
✅ 10
Q 29: In DNA, distance between adjacent base pairs is
✅ 0.34 nm (3.4 Å)
Q 30: Number of base pairs in human DNA is
✅ 6.6 x 109
Q 31: Length of human DNA is about
✅ 2.2 m
Q 32: The genetic information flows from DNA → RNA → Protein. This is called
✅ Central dogma of Molecular Biology
Q 33: Central dogma of Molecular Biology is proposed by
✅ Francis Crick
Q 34: In some viruses, flow of information is in reverse direction (from RNA to DNA). It is called
✅ Reverse transcription
Q 35: In prokaryotes such as E. coli, the negatively charged DNA is held with some positively charged proteins in a region called
✅ Nucleoid
Q 36: In eukaryotes, there is a set of positively charged, basic proteins called
✅ Histones
Q 37: Histones are rich in positively charged basic amino acid residues called
✅ lysines and arginines
Q 38: Eight histones form .......
✅ Histone octamer
Q 39: Negatively charged DNA is wrapped around histone octamer to give ……………
✅ Nucleosome
Q 40: A typical nucleosome contains ....... bp.
✅ 200 bp
Q 41: Total number of nucleosomes in human is about
✅ 3.3 x 107
Q 42: Nucleosomes constitute the repeating unit to form
✅ Chromatin
Q 43: Nucleosomes in chromatin is like …………. when viewed under electron microscope.
✅ Beads-on-string
Q 44: The beads-on-string structure in chromatin is packaged to form chromatin fibres that are further coiled and condensed at metaphase stage to form
✅ Chromosomes
Q 45: Higher level packaging of chromatin in eukaryotes requires
✅ Non-histone chromosomal (NHC) proteins
Q 46: Loosely packed, light stained and transcriptionally active region of chromatin is called
✅ Euchromatin
Q 47: Densely packed, dark stained and inactive region of chromatin is called
✅ Heterochromatin
Topic 2: THE SEARCH FOR GENETIC MATERIAL
Q 48: Transforming principle experiment was first conducted by …………
✅ Frederick Griffith
Q 49: Streptococcus pneumoniae has 2 strains such as Smooth (S) strain and ………….
✅ Rough (R) strain
Q 50: Which strain of Streptococcus pneumoniae has polysaccharide mucus coat and causes pneumonia?
✅ Smooth (S) strain
Q 51: R strain bacteria and ………. bacteria cannot cause pneumonia in mice.
✅ Heat killed S strain
Q 52: When Griffith injected a mixture of heat killed S strain and…………, mice died.
✅ Live R-strain
Q 53: Griffith named the substance transferred from heat-killed S-strain to R-strain as
✅ Transforming principle
Q 54: Oswald Avery, Colin MacLeod & Maclyn McCarty proved that the transforming principle in Griffith’s experiment is ………….
✅ DNA
Q 55: Who proved that DNA is the genetic material by conducting experiment using bacteriophage viruses and E. coli?
✅ Alfred Hershey & Martha Chase
Q 56: In Hershey-Chase experiment, viruses grown in P32 got radioactive DNA and viruses grown in S35 got
✅ Radioactive protein
Q 57: In ……... experiment, bacteria infected with viruses having radioactive DNA were radioactive. This proves that DNA is the genetic material.
✅ Hershey-Chase
Topic 3: PROPERTIES OF GENETIC MATERIAL (DNA v/s RNA)
Q 58: Single stranded structure and presence of …………. and 2’-OH in ribose sugar are the important reasons for the mutability or high reactivity of RNA.
✅ Uracil
Q 59: Viruses such as Q.B bacteriophage, Tobacco Mosaic Virus etc. mutate and evolve faster. This is because their genetic material is ……….
✅ RNA
Q 60: Which experiment gives a proof for the stability of DNA?
✅ Griffith’s experiment
Q 61: For the storage of genetic information, ……... is better due to its stability.
✅ DNA
Q 62: For the transmission of genetic information, ……… is better.
✅ RNA
Q 63: The first genetic material was ……….
✅ RNA
Q 64: DNA evolved from ………. for stability.
✅ RNA
Topic 4: REPLICATION
Q 65: The copying of DNA from parental DNA is called
✅ Replication
Q 66: Semi-conservative model of DNA replication was proposed by …………
✅ Watson & Crick
Q 67: After replication, each DNA molecule would have one parental and one new strand. This model of replication is called …………….
✅ Semi-conservative model
Q 68: …………. experimentally proved Semi-conservative model.
✅ Matthew Meselson & Franklin Stahl
Q 69: Meselson and Stahl grew E. coli in ………… medium. As a result, newly synthesised DNA was heavier.
✅ 15NH4Cl
Q 70: In Meselson-Stahl experiment, heavy DNA can be distinguished from normal DNA (light DNA or 14N DNA) by centrifugation in a …………
✅ Caesium chloride (CsCl) density gradient
Q 71: When E. coli cells from 15N medium were transferred to 14NH4Cl medium, DNA of next generation was …….. type.
✅ Hybrid type (15N -14N)
Q 72: Taylor & colleagues (1958) performed experiments on ……… using radioactive thymidine to detect distribution of newly synthesized DNA in the chromosomes.
✅ Vicia faba (faba beans)
Q 73: In living cells, such as E. coli, replication requires a set of enzymes such as
✅ DNA-dependent DNA polymerases
Q 74: DNA polymerases use DNA strands as templates to catalyse polymerisation of
✅ Deoxynucleotides
Q 75: There is a definite region in DNA where the replication originates. Such regions are called ……….
✅ Origin of replication
Q 76: In recombinant DNA procedures, the ………. provide the origin of replication.
✅ Vectors
Q 77: Replication occurs within a small opening of the DNA helix. It is called
✅ Replication fork
Q 78: During replication, DNA polymerases catalyse polymerisation in ………… direction.
✅ 5'→3'
Q 79: DNA replication is continuous on the template with the polarity .......
✅ 3'→5'
Q 80: The discontinuously synthesised DNA fragments are later joined by the enzyme .........
✅ DNA ligase
Q 81: E. coli completes the replication within
✅ 18 minutes
Q 82: In eukaryotes, the replication takes place at ………. of the cell-cycle.
✅ S-phase
Q 83: Failure in cell division after DNA replication results in
✅ Polyploidy
Topic 5: TRANSCRIPTION
Q 84: The process of copying genetic information from one strand of the DNA into RNA is called
✅ Transcription
Q 85: In transcription, adenine pairs with ……… instead of thymine.
✅ Uracil
Q 86: During transcription, the ……………. enzyme catalyzes the polymerization only in 5’→3’direction.
✅ DNA-dependent RNA polymerase
Q 87: During transcription, 3’→5’ strand acts as template strand and 5’→3’ acts as
✅ Coding strand
Q 88: The segment of DNA between the sites of initiation and termination of transcription is called
✅ Transcription Unit
Q 89: In a transcription unit, the binding site for RNA polymerase located towards 5'-end is called
✅ Promoter
Q 90: The region between promoter and terminator where transcription takes place is called
✅ Structural gene
Q 91: In a transcription unit, the site towards 3'-end where transcription stops is called
✅ Terminator
Q 92: ………. is a functional unit of inheritance.
✅ Gene
Q 93: Gene is the DNA sequence coding for ………...
✅ RNA
Q 94: A segment of DNA coding for a polypeptide during protein synthesis is called
✅ Cistron
Q 95: In structural genes of eukaryotes, the coding sequences (exons or expressed sequences) are interrupted by introns (intervening sequences). They are called
✅ Monocistronic structural genes (split genes)
Q 96: Polycistronic structural genes are seen in
✅ Prokaryotes
Q 97: In bacteria (Prokaryotes), synthesis of all types of RNA are catalysed by a single enzyme called
✅ RNA polymerase
Q 98: For the initiation of transcription, an initiation factor called ………… binds with RNA polymerase which helps the enzyme to bind at the promoter site of DNA.
✅ σ factor
Q 99: During transcription, the substrates used for the polymerisation are ……….
✅ Nucleoside triphosphates
Q 100: During termination of transcription, a …………… binds to the RNA polymerase and terminates the transcription.
✅ ρ factor (Termination factor)
Q 101: The enzyme that transcribes rRNAs (28S, 18S & 5.8S) is
✅ RNA polymerase I
Q 102: The enzyme ……………… transcribes the heterogeneous nuclear RNA (hnRNA).
✅ RNA polymerase II
Q 103: The precursor of mRNA or primary transcripts is called
✅ Heterogeneous nuclear RNA (hnRNA)
Q 104: tRNA, 5S rRNA and snRNAs (small nuclear RNAs) are transcribed by
✅ RNA polymerase III
Q 105: Splicing is a process in which ……… are removed from hnRNA and exons are spliced (joined) together.
✅ Introns
Q 106: In Capping, a nucleotide ………. is added to the 5’ end of hnRNA.
✅ Methyl guanosine triphosphate
Q 107: During …………., 200 to 300 adenylate residues are added at 3’-end of hnRNA.
✅ Tailing (Polyadenylation)
Topic 6: GENETIC CODE
Q 108: The sequence of nucleotides (nitrogen bases) in mRNA that contains information for protein synthesis is called
✅ Genetic code
Q 109: The sequence of 3 bases determining a single amino acid is called
✅ Codon
Q 110: ……….. suggested that for coding 20 amino acids, the code should be made up of 3 nucleotides.
✅ George Gamow
Q 111: …………… developed the chemical method in synthesizing RNA molecules with defined combinations of bases.
✅ Har Gobind Khorana
Q 112: Who developed cell-free system for protein synthesis?
✅ Marshall Nirenberg
Q 113: Which enzyme is used to polymerize RNA with defined sequences in a template independent manner?
✅ Severo Ochoa (polynucleotide phosphorylase) enzyme
Q 114: How many codons code for amino acids?
✅ 61
Q 115: Which of the following is not a Stop codon (Termination codons?
UAA, AUG, UAG, UGA.
UAA, AUG, UAG, UGA.
✅ AUG
Q 116: Some amino acids are coded by more than one codon. Such codons are called
✅ Degenerate codons
Q 117: AUG has dual functions. It codes for Methionine and acts as ………..
✅ Initiator codon
Q 118: Insertion or deletion of one or two bases changes the reading frame from the point of insertion or deletion. It is called
✅ Frame-shift insertion or deletion mutations
Q 119: Name the RNA that provides template for translation (protein synthesis).
✅ mRNA (messenger RNA)
Q 120: …………… has structural and catalytic role during translation.
✅ rRNA (ribosomal RNA)
Q 121: Which RNA brings amino acids for protein synthesis and reads the genetic code?
✅ tRNA (transfer RNA)
Q 122: tRNA is also called …………..
✅ sRNA (soluble RNA)
Q 123: ………… postulated about an adapter molecule that can read the code and to link with amino acids.
✅ Francis Crick
Q 124: Which RNA has a role of an adapter molecule?
✅ tRNA
Q 125: tRNA has an …………. that has bases complementary to the codon.
✅ Anticodon loop
Q 126: Secondary structure of tRNA looks like a .........
✅ Clover-leaf
Q 127: In actual structure, the tRNA is a compact molecule which looks like ……………
✅ inverted L
Topic 7: TRANSLATION (PROTEIN SYNTHESIS)
Q 128: The process of polymerisation of amino acids to form a polypeptide based on the sequence of codons in mRNA is called …………….
✅ Translation
Q 129: Translation takes place in
✅ Ribosomes
Q 130: Ribosome consists of structural RNAs and about ………... types of proteins.
✅ 80
Q 131: Ribosome also acts as a catalyst for the formation of …………… between amino acids.
✅ Peptide bond
Q 132: …………. in bacteria is a ribozyme.
✅ 23S rRNA
Q 133: Amino acids are activated in presence of ATP and linked to their cognate tRNA. It is called
✅ Charging (aminoacylation) of tRNA
Q 134: During the initiation of translation, ribosome binds to the mRNA at the start codon called
✅ AUG
Q 135: Start codon is recognised by the initiator tRNA that carries the amino acid …………..
✅ Methionine
Q 136: During elongation process of translation, charged tRNA sequentially bind to the appropriate codon in mRNA by forming complementary base pairs with ………
✅ tRNA anticodon
Q 137: …………. moves from codon to codon along the mRNA.
✅ Ribosome
Q 138: When a …………. binds to stop codon, the translation terminates.
✅ Release factor
Q 139: An mRNA has additional sequences that are not translated. It is called
✅ Untranslated regions (UTR)
Q 140: ………. are required for efficient translation process.
✅ UTRs
Topic 8: REGULATION OF GENE EXPRESSION
Q 141: In the following levels of gene expression, which is absent in prokaryotes?
Transcriptional level
Processing level
Transport of mRNA from nucleus to the cytoplasm
Translational level
Transcriptional level
Processing level
Transport of mRNA from nucleus to the cytoplasm
Translational level
✅ Processing level
Q 142: In E. coli, the …………… enzyme hydrolyses lactose into galactose & glucose.
✅ Beta-galactosidase
Q 143: If a substrate is added to growth medium of bacteria, a set of genes is switched on to metabolize it. It is called
✅ Induction
Q 144: When a metabolite (product) is added, the genes to produce it are turned off. This is called
✅ Repression
Q 145: A group of genes regulating a metabolic reaction is called ……….
✅ Operon
Q 146: …………. is an operon that controls lactose metabolism in bacteria.
✅ Lac operon
Q 147: Lac operon was first elucidated by
✅ Francois Jacob and Jacque Monod
Q 148: In lac operon, a ………… is regulated by a common promoter and regulatory gene.
✅ Polycistronic structural gene
Q 149: In Lac operon, the gene that codes for repressor protein is called
✅ Regulatory or inhibitor (i) gene
Q 150: In Lac operon, there are 3 structural genes such as …………
✅ z, y a
Q 151: The z gene codes for …………… that hydrolyses lactose to galactose and glucose.
✅ ꞵ-galactosidase
Q 152: The y gene codes for Permease that increases permeability of the cell to .........
✅ ꞵ-galactosides (lactose)
Q 153: The a gene codes for an enzyme ..........
✅ Transacetylase
Q 154: If there is no ……… lac operon remains switched off.
✅ Lactose (inducer)
Q 155: The repressor protein binds to the ……… region and blocks RNA polymerase movement so that structural genes are not expressed.
✅ Operator
Q 156: If lactose or allolactose is provided in the growth medium, it is transported into bacterial cells by the action of
✅ Permease
Q 157: ………. binds with repressor protein, so that repressor protein cannot bind to operator region.
✅ Lactose (inducer)
Q 158: A very low-level expression of lac operon is always present to uptake ……… into the cells.
✅ Lactose
Q 159: In lac operon, glucose or galactose cannot act as ……….
✅ Inducers
Q 160: Regulation of lac operon by repressor is called
✅ Negative regulation
Topic 9: HUMAN GENOME PROJECT (HGP)
Q 161: The entire DNA in the haploid set of chromosomes of an organism is called a ..........
✅ Genome
Q 162: Human genome contains about ........
✅ 3x109 bp
Q 163: The first mega project for the sequencing of nucleotides and mapping of the genes in human genome was
✅ Human Genome Project (HGP)
Q 164: HGP was coordinated by U.S. Department of Energy and the ..............
✅ National Institute of Health
Q 165: ELSI stands for ……….
✅ Ethical, legal and social issues
Q 166: There are 2 major approaches in methodologies of HGP such as Expressed Sequence Tags (ESTs) and …….
✅ Sequence annotation
Q 167: The approach focused on identifying all the genes that are expressed as RNA is
✅ Expressed Sequence Tags (ESTs)
Q 168: The approach of sequencing of whole genome including all the coding and non-coding sequence and later assigning different regions in the sequence with functions is
✅ Sequence annotation
Q 169: In HGP, DNA fragments were cloned in a host (bacteria & yeast) using vectors such as BAC and …….. for amplification.
✅ YAC (Yeast Artificial Chromosomes)
Q 170: BAC stands for
✅ Bacterial Artificial Chromosomes
Q 171: The DNA fragments were sequenced using automated DNA sequencers that worked on the principle of a method developed by
✅ Frederick Sanger
Q 172: ……… has also developed method for sequencing of amino acids in proteins.
✅ Sanger
Q 173: HGP was closely associated with the rapid development of a new area in biology called
✅ Bioinformatics
Q 174: Of the 24 chromosomes (22 autosomes and X & Y), the last sequenced one is
✅ Chromosome 1
Q 175: Human genome contains …………. million nucleotide bases.
✅ 3164.7
Q 176: Total number of genes in human genome is about
✅ 30,000
Q 177: In human genome, average gene consists of ………… bases.
✅ 3000
Q 178: Largest known human gene is ………. on X-chromosome that contains 2.4 million bases.
✅ Dystrophin
Q 179: ……….. nucleotide bases are same in all people.
✅ 99.9%
Q 180: According to the Human Genome Project, the human chromosome with the least number of genes is the ………… which has about 231 genes.
✅ Y chromosome
Q 181: The human chromosome with the greatest number of genes is………… which has about 2968 genes.
✅ Chromosome 1
Q 182: Less than …… of the genome codes for proteins.
✅ 2%
Q 183: The stretches of DNA sequences of human genome that are repeated many times are called
✅ Repeated (repetitive) sequences
Q 184: About 1.4 million locations in human genome have single-base DNA differences. They are called
✅ SNPs (Single nucleotide polymorphism or snips)
Topic 10: DNA FINGERPRINTING (DNA PROFILING)
Q 185: The technique to identify the similarities and differences of the DNA fragments of 2 individuals is called
✅ DNA fingerprinting
Q 186: DNA fingerprinting was developed by
✅ Alec Jeffreys
Q 187: The bulk DNA forms a major peak and the small peaks are called
✅ Satellite DNA
Q 188: A DNA sequence which is tandemly repeated in many copy numbers is called
✅ Variable number tandem repeats (VNTR)
Q 189: VNTR belongs to ……….. DNA.
✅ Mini-satellite
Q 190: The size of VNTR varies from
✅ 0.1 to 20 kb
Q 191: Any difference in the nucleotide sequence (inheritable mutation) observed in a population is called
✅ DNA polymorphism
Q 192: The technique used in the procedure of DNA fingerprinting is
✅ Southern Blotting Technique
Q 193: In DNA fingerprinting, digestion of DNA is carried by
✅ Restriction endonucleases
Q 194: DNA fragments are separated by
✅ Gel electrophoresis
Q 195: In DNA fingerprinting, DNA fragments are transferred (blotting) to synthetic membranes such as
✅ Nitrocellulose or nylon
Q 196: In DNA fingerprinting, DNA fragments are hybridized using radioactive labelled ……….
✅ VNTR probe
Q 197: DNA fingerprint differs in everyone except in .........
✅ Monozygotic (identical) twins
Q 198: The sensitivity of the technique can be increased by use of
✅ Polymerase chain reaction (PCR)
Q 199: …………….. is used as a forensic tool to solve paternity, rape, murder etc. and for the diagnosis of genetic diseases
✅ DNA fingerprinting