In a dsDNA molecule, the percentage composition of Adenine was found to be 19%. What is the expected percentage of Uracil in this molecule?
1. 0 2. 19
3. 31 4. 38

Subtopic:  DNA Double Helix |
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The Central dogma in molecular biology:
I: was proposed by James Watson and Francis Crick with inputs from Maurice Wilkins and Rosalind Franklin.
II: states that the genetic information flows from DNA → RNA → Protein.
   
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
Subtopic:  DNA Double Helix |
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In a typical human cell:
I: the total number of bp in DNA present is about 6.6 × 109
II: the total length of unwinded DNA is approximately 2.2 metres
III: the dimension of nucleus is approximately 10–6 m
 
1. Only I and II are correct
2. Only II and III are correct
3. I, II and III are correct
4. I, II, and III are incorrect
Subtopic:  DNA Packaging |
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Prior to the work of Oswald Avery, Colin MacLeod and Maclyn McCarty (1933-44), the genetic material was thought to be:
1. a protein
2. a polysaccharide
3. a lipid
4. an RNA
Subtopic:  Search for Genetic Material:I | Search for Genetic Material: II |
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Beginning with \(^{15} \text N ^{15} \text N\) DNA [\(^{15} \text N\) is the heavy isotope of nitrogen] and after two rounds of replication in \(^{14} \text N\) medium, E.coli cells will contain:
1. \(\small\mathrm{{25 \%~ { }^{15} {N}^{15} {N} { DNA}; ~50 \%~ { }^{15} {N}^{14} {N} { DNA};~ 25 \%~ { }^{14} {N}^{14} {N} { DNA} }}\)
2. \(\small\mathrm{{25 \%~ { }^{15} {N}^{14} {N} { DNA}; ~50 \%~ { }^{15} {N}^{15} {N}{ DNA};~25 \%~ { }^{14} {N}^{14} {N} { DNA} }}\)
3. \(\small\mathrm{50 \%~ { }^{15} {N}^{15} {N} { DNA}; ~50 \%~ { }^{15} {N}^{14} {N} { DNA} }\)
4. \(\small\mathrm{50 \%~ { }^{15} {N}^{14} {N}{ DNA}; ~50 \%~ { }^{14} {N}^{14} {N} { DNA}}\)
Subtopic:  DNA Replication |
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The main enzyme involved in DNA replication is referred to as DNA-dependent DNA polymerase, since:
1. it uses a DNA template to catalyse the polymerisation of deoxyribonucleotides.
2. it uses a DNA template to catalyse the polymerisation of ribonucleotides.
3. it uses an RNA template to catalyse the polymerisation of deoxyribonucleotides.
4. it uses an RNA template to catalyse the polymerisation of ribonucleotides.
Subtopic:  DNA Replication: I |
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The promoter in a transcription unit:
I: is said to be located towards 3'-end (upstream) of the structural gene (the reference is made with respect to the polarity of template strand).
II: is a DNA sequence that provides binding site for RNA polymerase.
III: defines the template and coding strands.
1. Only I and II are correct
2. Only I and III are correct
3. Only II and III are correct
4. I, II and III are correct
Subtopic:  Transcription |
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Allelic sequence variation has traditionally been described as a DNA polymorphism if more than one variant (allele) at a locus occurs in human population with a frequency greater than:
1. 0.01 2. 0.05
3. 0.10 4. 1.00
Subtopic:  DNA Fingerprinting |
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The technique of DNA Fingerprinting was initially developed by:
1. Kary Mullis 2. Alec Jeffreys
3. Paul Berg 4. Thomas Cech
Subtopic:  DNA Fingerprinting |
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In DNA fingerprinting involving Southern blot hybridisation using radiolabelled VNTR as a probe, the correct chronology of steps between isolation of DNA [first step] and detection of hybridised DNA fragments by autoradiography [last step] is:
1. separation of DNA fragments by electrophoresis → digestion of DNA by restriction endonucleases → transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon → hybridisation using labelled VNTR probe
2. digestion of DNA by restriction endonucleases →separation of DNA fragments by electrophoresis → transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon → hybridisation using labelled VNTR probe
3. separation of DNA fragments by electrophoresis → digestion of DNA by restriction endonucleases → hybridisation using labelled VNTR probe → transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon
4. digestion of DNA by restriction endonucleases →separation of DNA fragments by electrophoresis → hybridisation using labelled VNTR probe → transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon
Subtopic:  DNA Fingerprinting |
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