Biomolecules MCQs | Biomolecules Short Questions and Answers

Questions
1 The backbone of DNA is
A hydrophilic
B hydrophobic
C nuetral
D Both hydrophilic and hydrophobic

Answer:hydrophilic
2 Which is the most stable form of DNA under normal physiological conditions
A A-DNA
B B-DNA
C Z-DNA
D H-DNA

Answer: B-DNA
3 As far as the absorbance of DNA at 260nm. Which of the following is correct?
A individual nucleotides>ss DNA>dsDNA
B dsDNA>ssDNA> individual nucleotides
C ssDNA>dsDNA> individual nucleotides
D absorbance remains same

Answer:individual nucleotides>ss DNA>dsDNA
4 Which of the following statement is true?
A DNA is more stable than RNA in alkaline condition because of the presence of 3’OH
B DNA is more stable than RNA in alkaline condition because of the presence of 2’ H compared to RNAs 2’OH
C RNA is more stable than DNA in alkaline condition because of the presence of 2’ and 3’OH compared to DNAs 2’H and 3’OH
D Both are equally stable in alkaline condition

Answer:DNA is more stable than RNA in alkaline condition because of the presence of 2’ H compared to RNAs 2’OH
5 Dehydration of DNA samples may induce the formation of
A A-DNA
B B-DNA
C Z-DNA
D H-DNA

Answer: A-DNA
6 An increase in temperature of a DNA sample causes change in
A absorbance at 260nm
B viscosity
C phosphodiester linkage
D absorbance and viscosity

Answer:absorbance and viscosity
7 RNA-DNA hybrids are
A more stable than DNA-DNA hybrid
B more stable than RNA-RNA hybrid
C less stable than RNA-RNA hybrid
D less stable than RNA-RNA hybrid and DNA-DNA hybrid

Answer: less stable than RNA-RNA hybrid and DNA-DNA hybrid
8 An increase Tm (melting temperature) for a ds-DNA may be due to high content of
A A+G
B A+T
C C+G
D none of the above

Answer:C+G
9 Thymine is present in
A prokaryotic mRNA
B mammalian mRNA
C ribosomal RNA
D tRNA

Answer:tRNA
10 RNA is genetic material in
A some virusus and prokaryotes
B some viruses only
C some virusus, prokaryotes and some primitive eukaryotes
D none of the above

Answer:some virusus and prokaryotes
11 DNA has
A autocatalytic function
B heterocatalytic function
C both autocatalytic and heterocatalytic function
D none of the above

Answer:both autocatalytic and heterocatalytic function
12 A nucleoside is composed of
A a base+ a sugar
B a base+ a sugar+ phosphate
C a base+ a phosphate
D none of these

Answer:a base+ a sugar
13 Genetic mutation occurs in
A Protein
B RNA
C DNA
D Nucleus

Answer:DNA
14 DNA is present in
A nucleus only
B nucleus, mitochondria and ER
C nucleus, mitochondria and choloroplast
D nucleus, mitochondria and RER

Answer:nucleus, mitochondria and choloroplast
15 DNA is the genetic material in
A viruses, prokaryote and eukaryote
B prokaryote and eukaryote
C only in eukaryotes
D in some viruses, prokaryotes and eukaryotes

Answer:in some viruses, prokaryotes and eukaryotes
16 The two strands in a DNA double is joined by

dna

A Co-valent bond
B Hydrogen bond
C ionic bond
D phosphodiester bond

Answer:Hydrogen bond
17 Chromatin is composed of
A nucleic acids and protein
B nucleic acids only
C proteins only
D none of these

Answer:nucleic acids and protein
18 The basic repeating units of a DNA molecule is
A nucleoside
B nucleotide
C histones
D aminoacids

Answer:nucleotide
19 Adjacent nucleotides are joined by
A covalent bond
B phosphodiester bond
C ionic bond
D peptide bond

Answer:phosphodiester bond
20 The length of one turn of DNA is
A 3.4 Ao
B 34 Ao
C 20 Ao
D 3.04 Ao

Answer:34 Ao
ADRE 3.0 Complete Study Material