Question 2 :
Which one of the following combinations is found in DNA ?
Question 4 :
Which one of the following is the complementary sequence for the DNA with $5'$-CGTACTA-$3'$.
Question 5 :
Choose the correct answer from the alternatives given :<br>Ifthe sequence of nitrogen bases of the coding strand of DNA in a transcriptionunit is: 5 - A T G A AT G - 3, the sequence of bases in its RNA transcriptwould be
Question 6 :
According to Watson-Crick model, hydrogen bonding in a double-stranded DNA occurs between.
Question 10 :
What is the length of human DNA containing $6.6\times10^9$ bp nitrogen bases?
Question 11 :
Watson and Crick were awarded Nobel Prize for their finding of
Question 12 :
<i></i><i></i>The experimental system used in studies of the discovery ofreplication of DNA has been<br>
Question 16 :
Whichof the following biologists has been dubbed as the architect of molecular biology?
Question 17 :
In the double helix model of DNA, what would bethe distance between two consecutive base pairs?
Question 20 :
The two strands of double helix of DNA are linked together by hydrogen bonds between
Question 21 :
In  a dsDNA number of phosphodiester bonds are $3250$, then find the number of base pairs.
Question 24 :
The number of purines in a segment of DNA molecule is 68. What will be the number of pyrimdines in this segment ?
Question 25 :
Which of the following is the co-factor for origin of life from pre-RNA?
Question 28 :
In a double-stranded DNA, the sequence of base pairs in one strand is AGCTAAGC. What is the complementary sequence on the other strand?
Question 29 :
If the total amount of adenine and thymine in a double-stranded DNA is 60% the amount of guainine in this DNA will be<br/>
Question 31 :
The width of B-DNA is ______ and each turn of its helix has ______ nucleotides.
Question 32 :
Double helix model of DNA which was proposed by Watson and Crick was of<br/>
Question 33 :
The double helical model of the DNA was proposed by Watson and Crick based on that whatdata produced by Wilkins and Franklin?
Question 37 :
Which choice describes the incorrect statement regarding the bonding arrangement in the Watson-Crick model of DNA?
Question 40 :
In a DNA molecule, the phosphate group is attached to ____carbon of the sugar residue of its own nucleotide and _____ carbon of the sugar residue of the next nucleotide by ____bonds.<br/>
Question 42 :
Choose the correct answer from the alternatives given :<br>Ina DNA strand the nucleotides are linked together by
Question 44 :
1.38 milimeter DNA is present in E. coli. How many base pair will be present in it?
Question 47 :
Histones are group of proteins which are rich in basic amino acids and they perform the function of
Question 48 :
Choose the correct answers from the alternatives given :<br>Ifthe sequence of bases in DNA is TAGC, then the sequence of bases in RNA wouldbe
Question 50 :
A mixture of equal numbers of fast and slow dividing cells is cultured in a medium containing a trace amount of radioactively labeled thymidine for one hour. The cells are then transferred to regular (unlabelled) medium. After 24 hrs of growth in regular media.
Question 51 :
A segment of DNA contains 1200 nucleotides, of which 200 have adenine base. How many cytosine bases are present in this segment of DNA?
Question 53 :
Assertion: DNA is more stable while RNA is more reactive.
Reason: DNA was first discovered by Watson and Crick (1953).
Question 54 :
The bond formed between phosphate and pentose sugars of DNA is
Question 57 :
Assertion: The heterocyclic compounds in nucleic acid are the nitrogenous bases.
Reason: Adenine and guanine are substituted pyrimidines while uracil, cytosine and thymine are substituted purines.
Question 59 :
Under electron microscope, chromatin fibres appear like beads in a string. The beads are
Question 61 :
One turn of the helix in a B-form DNA is approximately 
Question 62 :
Due to the discovery of which of the following in 1980, the evolution was termed as RNA world?
Question 65 :
"It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanisms for the genetic material," this is written by 
Question 66 :
How many among the following organisms hve linear ds DNA as their genetic material?<br>Homo sapiens, Escherichia coil, Drosophila, $\phi \times 174$ bacteriophage
Question 67 :
Given the fact that histone binds DNA, it should be rich in.
Question 70 :
Hypothesis of ''African origin'' of man is based on the study of____________
Question 74 :
Desert temperature often varies between  0 to 50$^o$C. The DNA polymerase isolated from a camel living in the desert will be able to synthesize DNA most efficiently at
Question 75 :
Read the statements given below.<br/><br/>I. Thiamine and Uracil are pyrimidines found in DNA & RNA respectively.<br/>II. Number of base pairs per turn in B - DNA helix is 10.<br/><br/>Choose the correct option.
Question 77 :
No. of of phosphoester bonds found in one turn of DNA is ____________.
Question 78 :
Nobel Prize to A. Kornberg and S. Ochoa was given for
Question 80 :
If percentage of cytosine is 18%, what will be the percentage of adenine?<br/>
Question 84 :
In the Watson and Crick model of DNA, the steps of the ladder are composed of
Question 85 :
DNA in the nucleus of rabbit egg is 1.8 picograms, its liver cell will have mass of DNA ______ picograms.
Question 87 :
Choose the correct answer from the alternatives given :<br>Referto the given steps Of DNA replication.<br>(i)Exposure of DNA strands<br>(ii)Synthesis of RNA primer<br>(iii)Activation of deoxyribonucleotides<br>(iv)Chain formation<br>(v)Base pairing<br>(vi) Proof reading and DNA repair<br>(vii)DNA polymerase attaches at Or site<br>Selectthe correct sequence of DNA replication.<br>
Question 89 :
Choose the correct answer from the alternatives given :<br>Whichof the following phenomena was experimentally proved by Meselson and Stahl?
Question 90 :
Two students are given two different double stranded DNA molecules of equal length. They are asked to denature the DNA molecules by heating. The DNA given to student A has a following composition of base (A : G : T : C :: 35 : 15 : 35 : 15) while that given to student B is (A : G : T:  C :: 12 : 38 : 12 : 38). Which of the following statement is true?<br/>
Question 91 :
Palaeontologists unearthed a human skull during excavation.  A small fragment of the scalp tissue was still attached to it. Only little DNA could be extracted from it. If the genes of the ancient man need to be analysed, the best way of getting sufficient amount of DNA from this extract is <br/>
Question 93 :
Choose the correct answers from the alternatives given :<br>Whichof the following regarding DNA is not true?
Question 96 :
Choose the correct answer from the alternatives given :<br>Watson and Crick (1953) proposed DNA double helix model and won the Nobel Prize; their model of DNA was based on<br><b></b>(i) X-ray diffraction studies of DNA done by Wilkins and Franklin<br>(ii) Chargaffs base equivalence rule<br>(iii) Griffiths transformation experiment<br>(iv) Meselson and Stahls experiment.<br>
Question 97 :
If the total amount of adenine and thymine in a double-stranded DNA is 45%, the amount of guanine in this DNA will be<br/>
Question 99 :
Out of A-T, G-C pairing, bases of DNA may exist in alternate valency state owing to arrangement called as
Question 100 :
Read the following statements and select the Correct option.<br>(i) Loosely packed and lightly stained region of chromatin are called as heterochrormatin.<br>(ii) Densely packed and dark stained region of chromatin are called as euchromatin.<br>(iii) A typical nucleosome contains 200 bp of DNA helix.<br>
Question 101 :
Taylor conducted the experiments to semiconservative mode of chromosome replication on
Question 105 :
Why does synthesis of DNA proceed only in the $5'$ to $3'$ direction?
Question 107 :
Transfer of DNA bands from an agarose gel to a nitrocellulose or nylon membrane is referred to as
Question 108 :
Assertion: Histones are basic proteins of major importance in packaging of eukaryotic DNA. DNA and histones comprise chromatin forming the bulk of eukaryotic chromosome.
Reason: Histones are of five major types: H1, H2A, H2B, H3 and H4.
Question 110 :
Watson & Crick proposed the model of DNA structures in which of the following years?<br/>
Question 111 :
Choose the correct answers from the alternatives given.<br>What is the function of DNA ligase in recombinant technology?
Question 112 :
A short length of DNA molecule has 80 thymine and 80 guanine bases. The total number ofnucleotids in the DNA fragment is
Question 113 :
A $340\overset {\circ}{A}$ long segment of DNA molecule has $20$ thymine nitrogenous bases, what will be the number of guanine nitrogen bases in the same segment?
Question 114 :
If the length of DNA strand is ${ 68A }^{ \circ }$ then, what will be the number of nucleotides present in DNA molecule
Question 115 :
"It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for genetic material" - This is written by<br/>
Question 116 :
<i>E. coli</i>, to be replicated, is placed in a medium containing radioactive thymidine for five minutes. Then it is made to replicate in a normal medium. Which of the following observation will be correct ?
