Nucleic Acids MCQs : This section focuses on the "Nucleic Acids". These Multiple Choice Questions (MCQs) should be practiced to improve the Nucleic Acids skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
The unfavourable free energy associated with not satisfying a hydrogen bond after formation of the double helix is approximately
A. 10 kJ/mol
B. 20 kJ/mol
C. 25 kJ/mol
D. 30 kJ/mol
Nucleotide bases and aromatic amino acids absorb light respectively at
A. 280 and 260 nm
B. 260 and 280 nm
C. 270 and 280 nm
D. 260 and 270 nm
Nucleic acids can be analyzed experimentally by their
A. molecular weight
B. absorption of visible light
C. absorption of uv light
D. none of these
Nucleoside is a pyrimidine or purine base
A. covalently bonded to a sugar
B. ionically bonded to a sugar
C. hydrogen bonded to a sugar
D. none of the above
Because DNA is a highly charged polyanion, its stability to heat denaturation
A. does not depend on hydrophobic interactions
B. increases with increasing salt
C. is independent of G - C content
D. decreases with increasing salt
In gel electrophoresis, what fragments will move most quickly through a gel?
A. Large fragments
B. Small fragments
C. Large genome
D. None of these
A five carbon sugar lacking a hydrogen at the number 2 carbon is found in
A. can participate in hydrophobic interactions due to its methyl group
B. is replaced by uracil in RNA
C. normally forms two hydrogen bonds with adenosine
D. all of the above
A nucleotide consists of
A. a sugar, a base and a phosphate
B. a sugar and a phosphate
C. paired bases
D. a sugar, a base and three phosphates
Which of the following is found on RNA but not DNA?
The sugar in RNA is __________ , the sugar in DNA is __________
A. deoxyribose, ribose
B. ribose, deoxyribose
C. ribose, phosphate
D. ribose, uracil
The glycosidic bonds in DNA and RNA
A. connect the sugar to the base
B. can be hydrolyzed by OH- ion
C. stabilize Watson-Crick H-bonds
D. are free to rotate over about 180°
A purine with an amine (NH2) group on the 6th carbon is
Which of the following is a purine?
Which pyrimidine base contains an amino group at carbon 4?
The most stabilizing force for nucleic acids is
A. hydrogen bonds
B. electrostatic bond
C. Van der Waals
D. conformational entropy
DNA is a polynucleotide.
Identify the complementary strand of the DNA primary structure ATGCCGATC.
RNA on hydrolysis does not yield which of the following?
A. Amino acid
B. Pentose sugar
C. Nitrogen base
D. Phosphoric acid
The attachment between the base and sugar in a nucleotide is through ______ bond.
Nucleotides are linked together by bonds between 5’ and 2’ carbons of two different pentose sugars.
Two DNA samples A and B have melting temperatures 305K and 320K respectively. Identify the correct statement based on this information.
A. A and B are complementary strands
B. B has more CG pairs than A
C. A has more CG pairs than B
D. A has more hydrogen bonds than B
Which of the following bases contain two keto groups?
Which of the following best describes cytosine?
A. pyrimidine, present in RNA and DNA
B. pyrimidine, present only in DNA
C. purine, present only in RNA
D. purine, present in RNA and DNA
Which part of the nucleotide is responsible for the formation of bonds in DNA double helix?
C. Phosphate group
D. Hydroxyl group of sugar
Which sugar is present in RNA?
Which of the following statements is correct?
A. Adenine is a pyrimidine
B. DNA is made of amino acids
C. Nucleosides do not contain phosphorous
D. RNA contains thymine
ATP and GTP are __________
D. nucleic acids
How many types of nucleotides are present in DNA?
Purines and pyrimidines are different molecules.
What are the types of nucleic acids are found in living organisms?
A. deoxyribonucleic acid & nucleotide acid
B. deoxyribonucleic acid & ribonucleic acid
C. ribonucleic acid & nucleotide acid
D. ribonucleic acid & nucleoside acid
Which monomers compose the strands of nucleic acids?
A. Amino acids
C. Functional groups
A purified DNA sample of leaf contains 20.0 mole of guanine. Calculate the approximate percentage of purine residues?
Deoxyribose sugar is found in DNA.
Name the pyrimidine base which is found in RNA but not in DNA?
Name those purine bases which are commonly found in DNA and RNA?
A. Adenine and guanine
B. Cytosine and thymine
C. Adenine and thymine
D. Cytosine and guanine
The monomeric unit of nucleic acid are called ___________
The primary structure of DNA and RNA proceeds in which direction?
A. 3’ —–> 5҆’
B. 5’ —–> 3’
C. 4’ —–> 6’
D. 3’ —–> 6’
What is the energy currency of the living cell?
Which bond is used to stabilize the double helix of DNA?
A. Hydrophobic bond
B. Hydrogen bond
C. Covalent bond
D. Ionic bond
Which of these statements are INCORRECT according to chargaff’s rules?
A. The molar ratio of A to T or C to G = 1
B. The sum of purine = sum of pyrimidine
C. The % C+G ≠ % A+T
D. The composition of DNA remains the same in all the species
Who discovered nucleic acid?
A. Watson and Crick
C. Friedrich Miescher
D. Walter Gilbert