CBSE Questions for Class 12 Medical Biology Molecular Basis Of Inheritance Quiz 3 - MCQExams.com

The transcription unit extends from
  • TATA box to start point
  • TATA box to stop codon
  • Start point to stop codon
  • 35 sequence to start point
Which of the following amino acid has hydroxyl methyl group as its R group?
  • Serine
  • Proline
  • Alanine
  • Arginine

Two or more codons encoding the same amino acid is due to

  • Non-ambiguous
  • Degeneracy of codon
  • Non-overlapping of codon
  • Non-sense codon
How many nitrogenous bases are there in a codon?
  • 3
  • 2
  • 1
  • 5
What is the main aim of the human genome project?
  • To introduce new genes into humans
  • To identify and sequence all the genes present in human DNA
  • To develop better techniques for comparing two different human DNA samples
  • To remove disease causing genes from human DNA
What is the process of joining together different DNA fragments often referred as?
  • Transcription
  • Cloning
  • Gene splicing
  • DNA amplification
What is meant by DNA fingerprinting ?
  • Techniques used for molecular analysis of different specimens of RNA
  • Techniques used for identification of fingerprints of individuals
  • Molecular analysis of profiles of DNA samples
  • Analysis of DNA samples using imprinting devices
What is the total number of nitrogenous bases in human genome estimated?
  • 3.5 million
  • 35 thousand
  • 35 million
  • 3.1 billion
Human genome project was initiated by
  • Francis Collins and Roderick
  • Watson and Crick
  • Beadle and Tatum
  • Paul Berg and Wollman
Centre of DNA Fingerprinting and Diagnostics (CDFD) is located at?
  • Delhi
  • Chennai
  • Kolkata
  • Hyderabad
Which of the character is not applicable to tRNA?
  • It is the smallest of the RNAs
  • It acts as an adapter for amino acids
  • It has a clover leaf like structure
  • It is the largest of the RNAs
Which enzyme plays important role in transcription?
  • DNA dependent RNA polymerase
  • DNA dependent DNA polymerase
  • RNA dependent DNA polymerase
  • RNA dependent RNA polyrnerase
What is the basis of DNA fingerprinting ?
  • The double helix
  • Errors in base sequence
  • Polymorphism in sequence
  • DNA replication
  • DNA coiling
Gel electyrophoresis is used for
  • Construction of recombinant DNA by joining with cloning vectors
  • Isolation of DNA molecule
  • Cutting of DNA into fragments
  • Separation of DNA fragments according to their size
The two polynucleotide chain in DNA are:-
  • Semiconservative
  • Parallel
  • Discontinuous
  • Antiparallel
Assertion: DNA polymerase-I acts as proofreader.

Reason: DNA polymerase-I removes mismatched nucleotides.

  • If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  • If the assertion is true but the reason is false
  • If both the assertion and reason are false
  • If the assertion is false but reason is true
Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as 'start' or 'stop' codon : -
  • UCG Start
  • UUU Stop
  • UGU Leucine
  • UAC Tyrosine
Which one of the following pairs of terms/names mean one and the same thing?
  • Gene pool - Genome
  • Codon - Gene
  • Cistron - Triplet
  • DNA fingerprinting - DNA profiling
Production of a human protein in bacteria by genetic engineering is possible because
  • Bacterial cell can carry out the RNA splicing reactions
  • The mechanism of gene regulation is identical in humans and bacteria
  • The human chromosome can replicate in bacterial cell
  • The genetic code is universal
Assertion: The tRNA molecules possess anticodons.

Reason: It needs the message in form of codon.

  • If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  • If the assertion is true but the reason is false
  • If both the assertion and reason are false
  • If the assertion is false but reason is true
Variable number of tandem repeats (VNTRs) in the DNA molecule are highly useful in which of the following?
  • Recombinant DNA technology
  • DNA fingerprinting
  • Monoclonal antibody production
  • Stemcell culture
Semiconservative replication of DNA was first demonstrated in
  • Salmonella typhimurium
  • Drosophila melanogaster
  • Escherichia coli
  • Streptococcus pneumoniae
Assertion:  DNA fingerprinting involves identifying differences in some specific regions in DNA sequence.

Reason:  In repetitive DNA sequences, a small stretch of DNA is repeated many times.
  • If both the assertion and the reason are true and the reason

    is a correct explanation of the assertion
  • If both the assertion and reason are true but the reason is

    not a correct explanation of the assertion
  • If the assertion is true but the reason is false
  • If both the assertion and reason are false
  • If the assertion is false but reason is true
The following ratio is generally constant for a given species :-
  • T + C / G + A
  • G + C / A+ T
  • A + C / T + G
  • A + G / C +T
A codon in mRNA has
  • 3 bases
  • 2 bases
  • 1 base
  • Number of bases vary
Khorana and his colleague synthesized an RNA molecule with repeating sequences of U and G bases. The RNA with, UGUGUGUGUGUG produced a tetra-peptide with alternating sequences of cysteine and valine. This proves that codon for cysteine and valine is
  • UGG, GUU
  • UUG, GGU
  • UGU, GUG
  • GUG, UGU
The process of mRNA synthesis on a DNA is known as
  • Translation
  • Transcription
  • Transduction
  • Transformation
Genetic information in a DNA molecule is coded in the
  • sequence of nucleotides
  • base pairing
  • turning pattern of the helix
  • portion of each base present
If genetic code is tetraplet then what is the possible number of codons which code 20 types of amino acids?
  • 261
  • 64
  • 256
  • 43
In the double helix model of DNA as proposed by J. D. Watson and F.S.C. Crick, each base pair is how far from the next base pair:
  • 0.034nm
  • 0.34nm
  • 3.4nm
  • 34nm
Double helix model of DNA which was proposed by Watson and Crick was of
  • C-DNA
  • B-DNA
  • D-DNA
  • Z-DNA
B-DNA double helix makes a complete turn with
  • Every 10 base pairs
  • Every 20 base pairs
  • Every 36 base pairs
  • Every 3-6 base pairs
Which of the following is not directly formed from DNA?
  • DNA
  • Protein
  • m RNA
  • t RNA
What does bacterial genome contain?
  • Double stranded circular DNA
  • Double stranded linear DNA
  • Single stranded circular DNA
  • Single stranded DNA
Degeneracy of genetic code was discovered by
  • McClintock
  • Khorana
  • Ochoa
  • Baurnfield & Nirenberg
Genetic code was discovered by
  • Nirenberg & Matthaei
  • Kornberg & Crick
  • Khorana & Kornberg
  • Gamow
DNA polymerase is needed for
  • Replication of DNA
  • Synthesis of DNA
  • Elongation of DNA
  • All of the above
DNA directed synthesis of mRNA is called as
  • Transcription
  • Translocation
  • Transduction
  • Replication
During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG, then the nucleotide sequence in the mRNA would be
  • TATGC
  • TCTGG
  • UAUGC
  • UATGC
In bacteria, the codon AUG stands for
  • Glycine
  • Methionine
  • N-formyl methionine
  • Both B and C
During transcription, the DNA site at which RNA polymerase binds is called as
  • Promoter
  • Regulator
  • Receptor
  • Enhancer
In a mRNA sequence of N$$_2$$-base is 5' AUG GUG CUC AAA 3'. What is the correct sequence of anticodons which recognizes codons of mRNA

223013_be73a2020231455ab100aaa0c2b31684.png
  • a, b, c, d
  • d, a, b, c
  • c, d, b, a
  • d, c, b, a
Sometimes the starting codon is GUG in place of AUG, GUG normally stands for
  • Valine
  • Glycine
  • Methionine
  • Tyrosine
Transcription means synthesis of
  • DNA
  • Protein
  • mRNA
  • Enzyme
Degeneration of a genetic code is attributed to the
  • First member of a codon
  • Second member of a codon
  • Entire codon
  • Third member of a codon
One turn of the helix in a B form DNA is approximately
  • 20 nm
  • 0.34 nm
  • 3.4 nm
  • 2 nm
Which of the following is an initiation codon?
  • AUG
  • UAG
  • UGA
  • UAA
Genetic code is
  • Universal
  • Non-ambiguous
  • Triplet
  • All of the above
A sample of DNA is found to have the base composition (mole ratio) of A = 40, T = 22, G = 21 and C =This suggests
  • DNA is circular duplex.
  • DNA is linear duplex.
  • DNA is single stranded.
  • DNA has high melting point.
In $$Drosophila$$, a set of homeotic genes which control body plan at the time of organ differentiation is known as
  • TATA box
  • Homeobox
  • Pribnow box
  • All of the above
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