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Free download in PDF Nucleic Acid Multiple Choice Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams like Biotechnology, Genetics, JIPMER, NEET, AIIMS etc. These short solved questions or quizzes are provided by Gkseries.
(1)
Identify the purine base of nucleic acids in the following
[A]
Cytosine
[B]
Thymine
[C]
Uracil
[D]
Adenine
(2)
Which of the following statements is true?
[A]
Sugar component of a nucleotide is ribose
[B]
Sugar component of a nucleotide is deoxyribose
[C]
The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage
[D]
The sugar molecule of the nucleotide is in L-configuration
Answer: The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage
(3)
What is the composition of nucleoside?
[A]
a sugar + a phosphate
[B]
a base + a sugar
[C]
a base + a phosphate
[D]
a base + a sugar + phosphate
(4)
The sugar molecule in a nucleotide is
[A]
Pentose
[B]
Hexose
[C]
Tetrose
[D]
Triose
(5)
Arrangement of nucleotides in DNA can be seen by
[A]
Ultracentrifuge
[B]
X-Ray crystallography
[C]
Light microscope
[D]
Electron microscope
Answer: X-Ray crystallography
(6)
One of the following nucleic acids has a left handed helix
[A]
M-RNA
[B]
T-RNA
[C]
A-DNA
[D]
Z-DNA
(7)
Which of the following is true about Z-DNA helix?
[A]
It has alternating GC sequences
[B]
It is a permanent conformation of DNA
[C]
It tends to be found at the 3’ end of the genes
[D]
It has fewer base pairs per turn than B-DNA
Answer: It has alternating GC sequences
(8)
Which of the following statements is true?
[A]
The template strand matches the sequence of the RNA transcript
[B]
The two strands of DNA run parallel to each other
[C]
G-C bonds are much more resistant to denaturation than A-T rich regions
[D]
The common form of DNA is left handed
Answer: G-C bonds are much more resistant to denaturation than A-T rich regions
(9)
Which structural feature is shared by both uracil and thymine?
[A]
Both contain two keto groups
[B]
Both contain one methyl group
[C]
Both contain a five-membered ring
[D]
Both contain three nitrogen atoms
Answer: Both contain two keto groups
(10)
Histones
[A]
are negatively-charged globular proteins
[B]
contain both α-helix and β-pleated sheet
[C]
have molecular weights in excess of 100,000
[D]
contain high amounts of basic amino acids
Answer: contain high amounts of basic amino acids
(11)
Which is a property of both viral genetic material and bacterial genetic material?
[A]
Both can be double-stranded, circular DNA
[B]
Both can be single-stranded, linear RNA
[C]
Both can be compacted into inverted repeats
[D]
Both can be compacted into plasmids
Answer: Both can be double-stranded, circular DNA
(12)
Which are characteristics of bacterial genetic material?
[A]
It is double-stranded and supercoiled
[B]
It is single-stranded and relaxed
[C]
It is circular and compacted into palindromes
[D]
It is linear and attached to a protein scaffold
Answer: It is double-stranded and supercoiled
(13)
Assume that DNA molecules are studied in a variety of organisms and found to have the following properties. Which property would be consistent with the hypothesis that genetic material is composed of DNA?
[A]
DNA in all organisms is composed of the same nucleotides
[B]
DNA in an organism remains constant as the organism ages
[C]
DNA from two different organisms has the same base composition
[D]
DNA is different in two different cells of the same organism
Answer: DNA in an organism remains constant as the organism ages
(14)
A new virus, virus X, is isolated and studied. Which molecule is most likely to be the genetic material of virus X?
[A]
a linear DNA molecule containing 10,000 base-pairs
[B]
a linear RNA molecule containing plasmids
[C]
a circular DNA molecule containing nucleosomes
[D]
a circular RNA molecule with a molecular weight of 10 billion
Answer: a linear DNA molecule containing 10,000 base-pairs
(15)
Which describes the structural properties of a eukaryotic chromosome?
[A]
It contains a double-helix composed of nucleosomes each with four million base-pairs
[B]
It is one double-stranded linear DNA molecule bound to proteins for compaction
[C]
It is arranged into a 30 nm fiber which is attached to the cell membrane
[D]
It contains linker regions which are arranged into loops and coiled to form a helix
Answer: It is one double-stranded linear DNA molecule bound to proteins for compaction
(16)
If the following experimental results were obtained, which would be evidence
against DNA being the genetic material?
[A]
The base composition of DNA is the same in two different cells of the same organism
[B]
The viral components labeled with 32P remain outside the cell during a successful infection
[C]
The transforming factor isolated from a virulent bacterium is sensitive to deoxyribonucleases
[D]
The base composition of DNA in an organism remains constant as the organism ages
Answer: The viral components labeled with 32P remain outside the cell during a successful infection
(17)
Which is a characteristic of eukaryotic genetic material?
[A]
Eukaryotic genetic material consists of supercoiled circular DNA molecules complexed with proteins into chromosomes
[B]
Eukaryotic genetic material consists of relaxed linear DNA molecules complexed with RNA into a 30 nm fiber
[C]
Eukaryotic genetic material is compacted by wrapping the double-helix around histone proteins to form nucleosomes
[D]
Eukaryotic genetic material is compacted by folding linker regions around non-histone proteins to form a scaffold
Answer: Eukaryotic genetic material is compacted by wrapping the double-helix around histone proteins to form nucleosomes
(18)
Which property is shared by the five histone proteins?
[A]
They are acidic proteins with relatively large molecular weights
[B]
They are multimeric proteins with high levels of Arg and Lys
[C]
They are fibrous proteins with high amounts of α-helix
[D]
They are globular proteins with a positive charge
Answer: They are globular proteins with a positive charge
(19)
Which characteristic will be shared when comparing the single 5’-(GA)20-3’ strand to another single-stranded DNA molecule with the sequence 5’-(AT)20-3’?
[A]
Both contain a palindromic sequence
[B]
Both can form the same secondary structures
[C]
Both could hybridize to the same RNA molecule
[D]
Both will have the same overall charge
Answer: Both will have the same overall charge
(20)
Which of the following double-stranded DNA molecules would denature at about the same temperature as the double-stranded molecule containing a 5’-(GA)20-3’ strand?
[A]
a molecule which contains a (GC)20 strand
[B]
a molecule which contains a (TA)20 strand
[C]
a molecule which contains a (GACT)10 strand
[D]
a molecule which contains a (GGGA)10 strand
Answer: a molecule which contains a (GACT)10 strand
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