CBSE Questions for Class 12 Medical Biology Molecular Basis Of Inheritance Quiz 14 - MCQExams.com

Instead of 3, if it was 2 bases code for an amino acid, the degeneracy of codons coding for the same amino acid would have
  • Increased
  • Decreased
  • Remained the same
  • Been uncertain
Which amino acid is specified by genetic codes ACU, ACC, ACA, ACG showing degeneracy?
  • Leucine
  • Methionine
  • Glycine
  • Threonine
Complete turns in 45,000 bp DNA would be
  • 45
  • 450
  • 4,500
  • 45,000
DNA finger printing is related to
  • Techniques used in identification of finger prints of different persons
  • Analysis of DNA samples using imprinting devices
  • Techniques used for molecular analysis of different specimens of DNA
  • None of the above
For the structure of nucleic acid, which of the following statements is wrong?
  • DNA can be single stranded in some viruses.
  • RNA can be double stranded occasionally.
  • There are as many as 12 bases per turn in Z DNA.
  • The length of one helix is 45$$\mathring A$$ in B-DNA and in Z-DNA.
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?
  • Both the DNA molecules would denature at the same rate.
  • The information given is insufficient to draw any conclusion.
  • DNA molecule given to student B would denature faster than that of student A.
  • DNA molecule given to student A would denature faster than that given to student B.
Degeneration of genetic code is due to
  • First member of codons
  • Second member of codons
  • Third member of codons
  • Entire codons
The amino acid sequences of a bacterial protein and a human protein carrying out similar function are found to be 60% identical. However, the DNA sequences of the genes coding for these proteins are only 45% identical. This is because
  • Protein sequence does not depend on DNA sequence.
  • DNA codons having different nucleotides in the third position can code for the same amino acids.
  • DNA codons having different nucleotides in the second position can code for the same amino acids.
  • Same DNA codons can code for multiple amino acids.
Which conserved motif occur in Escherichia coli genes?
  • TATA box
  • CAAT box
  • Pribnow box
  • None of the above
DNA fingerprinting is useful for the study of 
  • Polymorphism
  • Forensics
  • Identity and relationship
  • All of the above
Genetic code was deciphered by chemically synthesizing nucleotides by
  • Watson and Crick
  • Beadle and Tatum
  • M. Nirenberg and H. Khorana
  • K. Correns and Max Theiler
In DNA replication, the Okazaki fragments on the lagging strand are joined together by
  • DNA polymerase
  • Primase
  • Helicase
  • DNA ligase
Nirenberg used an artificial mRNA poly U (UUU...U), which gave rise to polyphenylalanine. This proved that
  • Artificial mRNA was not useful for the study of genetic code.
  • Genetic code is triplet.
  • Triplet UUU code for phenylalanine.
  • Genetic code is non overlapping.
Which of the following is known as joining enzyme or repair enzyme of DNA?
  • Transcriptase
  • Endonucleases
  • Ligases
  • Polymerase
Which one of the following, scientists developed the process of DNA fingerprinting?
  • Kary B. Mullis
  • T. H. Morgan
  • H. O. Smith
  • Alec Jeffreys
DNA fingerprinting technique was first developed by 
  • Boysen and Jensen
  • Jeffreys, Wilson and Thien
  • Schleiden and Schwann
  • Edward and Steptoe
Raghu is married to Radha, who was previously married to Varun, now deceased. Varun and Radha conceived one child together and adopted one child. Raghu and Radha have also conceived one child. All members of  Radha's current family have had DNA fingerprinting done. Unfortunately the sheet that identified each child has been misplaced. Identify which fingerprint in each lane corresponds to each child.
385816_e1895b8bef884133bd37145462f178b3.png
  • 1- child of Radha and Raghu; 2- adopted child; 3- child of Radha and Varun
  • 1- adopted child; 2- child of Radha and Raghu; 3- child of Radha and Varun
  • 1- adopted child; 2- child of Radha and Varun; 3- child of Radha and Raghu
  • 1- child of Radha and Varun; 2- child of Radha and Raghu; 3- adopted child
DNA fingerprinting refers to __________.
  • Analysis of DNA samples using imprinting devices
  • Techniques used for molecular analysis of different specimens of DNA
  • Techniques used for identification of fingerprints of individuals
  • Molecular analysis of profiles of DNA samples
Which is the most reliable method for identifying a person?
  • Karyotype examination
  • DNA fingerprinting
  • Antibody fingerprinting
  • All of the above
Why does synthesis of DNA proceed only in the $$5'$$ to $$3'$$ direction?
  • DNA polymerases can only add nucleotides to the $$3'$$ end of a polynucleotide strand.
  • The $$3'$$ end of the polynucleotide molecule is more electronegative than the $$5'$$ end.
  • This is the direction in which the two strands of DNA unzip.
  • The chromosomes are always aligned in the $$5'$$ to $$3'$$ direction in the nucleus.
DNA profiling can be carried out using
  • Blood
  • Saliva
  • Both A and B
  • None of the above
Which one of the following scientists developed the process of DNA fingerprinting?
  • Kary B. Mullis
  • T. H. Morgan
  • H. O. Smith
  • Alec Jeffreys
The commonly used DNA fingerprinting technique in forensic science study is
  • Southern blotting
  • Northern blotting
  • Eastern blotting
  • Western blotting
Helical structure of DNA was proposed by
  • Chargaff
  • Watson and Crick
  • Griffith
  • All
Major difference between replication in bacteria and animal cell is that 
  • Bacterial cell do not use topoisomerase in their replication
  • Replication is conservative in bacteria
  • DNA glycosylase performs the function of DNA helicase in bacteria
  • There is only one origin of replication in bacteria
Length of one turn of DNA is
  • 3.4 $$\mathring{A}$$
  • 34 $$\mathring{A}$$
  • 20 $$\mathring{A}$$
  • 3.04 $$\mathring{A}$$
DNA polymerase enzyme is required for the synthesis of
  • RNA from DNA
  • DNA from DNA
  • RNA from RNA
  • DNA from RNA
The process of the formation of RNA from DNA is
  • Transduction
  • Transcription
  • Transversion
  • Transition
Because most of the amino acids are represented by more than one codons, the genetic code is said to be
  • Deaminated
  • Comma less
  • Degenerate
  • Overlapping
The Human Genome Project (HGP) was initiated in
  • $$1988$$
  • $$1990$$
  • $$1992$$
  • $$1994$$
Which of the following techniques has helped to solve many mysteries involving murders, robberies and rapes?
  • Gene splicing
  • Computer technology
  • DNA fingerprinting
  • Gene cloning
Which of the following is correct pair of pyrimidine bases?
  • Adenine and Thymine
  • Adenine and Guanine
  • Thymine and Cytosine
  • Guanine and Cytosine
DNA fingerprinting relies on identifying specific
  • Coding sequences
  • Non-coding sequences
  • Both A and B
  • Restriction site
How many sense codons code for $$20$$ known essential amino acids?
  • $$61$$
  • $$62$$
  • $$63$$
  • $$64$$
A $$340$$ $${^\circ}{A}$$ long segment of DNA molecule has $$20$$ thymine nitrogenous bases, what will be the number of guanine nitrogen bases in the same segment?
  • $$10$$
  • $$40$$
  • $$80$$
  • $$160$$
The codon for anticodon 3'-UUUA-5' is
  • 3'-AAU-5'
  • 5'-UAAA-3'
  • 5'-AAAU-3'
  • 3'-UAAU-5'
The deflection of pitch angle between two successive steps (rungs) of DNA is
  • $$72^{\circ}$$
  • $$54^{\circ}$$
  • $$36^{\circ}$$
  • $$18^{\circ}$$
DNA fingerprinting is useful for the study of
  • Forensic science
  • Identity
  • Relationship
  • All of the above
A terminator codon which is called amber is
  • UGA
  • UAG
  • UAA
  • UUU
The nucleotide sequence on antisense strand of DNA which is transcribed as codon that specifies the amino acid serine is
  • TCA
  • AGU
  • TAC
  • CCC
From the given genetic code table, find out the 1$$^s$$$$^t$$ and last amino acid formed from the mRNA associated with the given DNA template strand.
479435_c1fde278cb95462e9e625b8db5a01084.png
  • Ala and stop codon
  • Arg and Cyst
  • Arg and stop codon
  • Ala and Trp
  • Tyr and Thr
In genetic fingerprinting, the 'probe' refers to a radioactively labelled
  • Double-stranded RNA molecule
  • Double-stranded DNA molecule
  • Single-stranded DNA molecule
  • Single-stranded RNA molecule
Which of the following is true about codon?
  • A group of three nucleotide sequences
  • The nucleotide units between the start and stop codes
  • The nucleotide sequence that serves as the instructions for a protein
  • A single nucleotide in an mRNA sequence
  • The sequence of nucleotides that signals the start or stop of protein sythesis
Which one of the following is start codon?
  • AUG
  • UGA
  • UAA
  • UAG
What will be the codons in m-RNA if the DNA codes are ATG-CAG?
  • TAC-GTC
  • UAC-GUC
  • UCA-TUA
  • TCA-GTC
Out of A-T, G-C pairing, bases of DNA may exist in alternate valency state owing to arrangement called as
  • Tautomerisational mutation
  • Analogue substitution
  • Point mutation
  • Frameshift mutation
An error in the polypeptide chain produced from DNA sequence is not always the result of mutation. The best explanation for this is that
  • Some polypeptides are produced by a code other than a nucleic acid code
  • The nucleolus can repair damaged DNA
  • The Golgi body can repair damaged DNA
  • Different codons code for the same amino acid
  • Scientists have no idea why this phenomenon occurs
The technique used to increase the amount of DNA available for analysis is
I. Cloning a plasmid
II. Gel electrophoresis
III. PCR
  • II only
  • I and II
  • I and III
  • II and III
  • I, II, and III
DNA-dependent RNA polymerase catalyze transcription on one strand of the DNA which is called the
  • Alpha strand
  • Antistrand
  • Template strand
  • Coding strand
The codons UUU and UUC codes for phenylalanine only. This feature of genetic code is called
  • Commaless
  • Non- overlapping
  • Degenerate
  • Non-ambiguous
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