NEET Biology Molecular Basis of Inheritance MCQs Set E

Question: Which of the following is not a property of the genetic code?

• a) Ambiguous
• b) Degeneracy
• c) Non-overlapping
• d) Universal

Answer: Ambiguous

Question: One of the most frequently used techniques in DNA fingerprinting is

• a) VNTR
• b) SSCP
• c) SCAR
• d) AFLP

Answer: VNTR

Question: In an inducible operon, the genes are

• a) Usually not expressed unless a signal turns them "on"
• b) Always expressed
• c) Usually expressed unless a signal turns them "off"
• d) Never expressed

Answer: Usually not expressed unless a signal turns them "on"

Question: A single strand of nucleic acid tagged with a radioactive molecule is called

• a) Probe
• b) Vector
• c) Selectable marker
• d) Plasmid

Answer: Probe

Question:

• a) Amino acid activation
• b) Amino acid assimilation
• c) Amino acid transformation
• d) Amino acid translocation

Answer: Amino acid activation

Question: The transcription of any gene is the indication of its

• a) Activity
• b) Stimulation
• c) Hypersensitivity
• d) Induction

Answer: Activity

Question: mRNA directs the building of proteins through a sequence of

• a) Codons
• b) Exons
• c) Anticodons
• d) Introns

Answer:  Codons

Question: Beadle and Tatum showed that each kind of mutant bread mould they studied lacked a specific enzyme. Their experiments demonstrated that

• a) Genes carry information for making proteins
• b) Genes are made of DNA
• c) Cells need specific enzymes in order to function
• d) Enzymes are required to repair damaged DNA information

Answer: Genes carry information for making proteins

Question: Which of the following necleotide sequences contain 4 pyrimidine bases?

• a) GATCAATGC
• b) GCUAGACAA
• c) UAGCGGUAA
• d) None of these

Answer: GATCAATGC

Question: The 1992 Nobel Prize for medicine was awarded to Edmond H. Fischer and Edwin J. Krebs for their work concerning

• a) Reversible protein phosphorylation as a biological regulation mechanism
• b) Isolation of the gene for a human disease
• c) Human genome project
• d) Drug designing involving inhibition of DNA synthesis of the pathogen

Answer: Reversible protein phosphorylation as a biological regulation mechanism

Question: Initiation codon in eukaryotes is

• a) AUG
• b) UAG
• c) AGU
• d) GAU

Answer: AUG

Question: ‘Lac operon’ in E. coli, is induced by

• a) Lactose
• b) Promoter gene
• c) “I” gene
• d) DNA gyrase

Answer: Lactose

Question: There are special proteins that help to open up DNA double helix in front of the replication fork. These proteins are

• a) DNA gyrase
• b) DNA polymerase I
• c) DNA ligase
• d) DNA ligase

Answer: DNA gyrase

Question: In protein synthesis, the polymerization of amino acids involves three steps. Which one of the following is not involved in the polymerization of protein?

• a) Transcription
• b) Elongation
• c) Initiation
• d) Termination

Answer: Transcription

Question: Anticodon is an unpaired triplet of bases in an exposed position of

• a) t-RNA
• b) m-RNA
• c) r-RNA
• d) s-RNA

Answer: t-RNA

Question: An environmental agent, which triggers transcription from an operon, is a

• a) Inducer
• b) Regulator
• c) Controlling element
• d) Depressor

Answer: Inducer

Question:  In split genes, the coding sequences are called

• a) Exons
• b) Cistrons
• c) Introns
• d) Operons

Answer: Exons

Question: The lac operon is an example of

• a) Inducible operon
• b) Arabinose operon
• c) Overlapping genes
• d) Repressible operon

Answer: Inducible operon

Question: If the DNA codons are ATG ATG ATG and a cytosine base is inserted at the beginning, then which of the following will result?

• a) CAT GAT GATG
• b) A non-sense mutation
• c) C ATG ATG ATG
• d) CA TGA TGA TG

Answer: CAT GAT GATG

Question: The wild type E.coli cells are growing in normal medium with glucose. They are transferred to a medium containing only lactose as sugar. Which of the following changes take place?

• a) The lac operon is induced
• b) The lac operon is repressed
• c) E.coli cells stop dividing
• d) All operons are induced

Answer: The lac operon is induced

Question: If the sequence of bases in DNA is ATTCGATG, then the sequence of bases in its transcript will be

• a) UAAGCUAC
• b) CAUCGAAU
• c) AUUCGAUG
• d) GUAGCUUA

Answer: UAAGCUAC

Question: Which of the following serves as an stop codon?

• a) UAG
• b) AGA
• c) AUG
• d) GCG

Answer: UAG

Question: The codons causing chain termination are

• a) UAG, UGA, UAA
• b) AGT, TAG, UGA
• c) TAG, TAA, TGA
• d) GAT, AAT, AGT

Answer: UAG, UGA, UAA

More Questions.......................................

Question: DNA synthesis can be specifically measured by estimating the incorporation of radio-labelled

• a) Thymidine
• b) Deoxyribose sugar
• c) Uracil
• d) Adenine

Answer: Thymidine

Question: Which of the following step of translation does not consume a high energy phosphate bond?

• a) Peptidyl transferase reaction
• b) Translocation
• c) Aminoacyl t-RNA binding to A-site
• d) Amino acid activation

Answer: Peptidyl transferase reaction

Question: DNA elements, which can switch their position, are called

• a) Transposons
• b) Cistrons
• c) Exons
• d) Introns

Answer:  Transposons

Question: Sequence of which of the following is used to know the phylogeny?

• a) DNA
• b) t-RNA
• c) r-RNA
• d) m-RNA

Answer: DNA

Question: Genes that are involved in turning on or off the transcription of a set of structural genes are called

• a) Regulatory genes
• b) Polymorphic genes
• c) Operator genes
• d) Redundant genes

Answer: Regulatory genes

Question: In operon concept, regulator gene functions as

• a) Repressor
• b) Inhibitor
• c) Regulator
• d) All of these

Answer: Repressor

Question: In DNA, when AGCT occurs, their association as per which of the following pair?

• a) AT-GC
• b) AG-CT
• c) AC-GT
• d) All of these

Answer:  AT-GC

Question:  Irregularity is found in Drosophila during the organ differentiation. For example, in place of wing Iong legs are formed. Which gene is responsible?

• a) Homeotic gene
• b) Complimentary gene
• c) Plastid gene
• d) Double dominant gene

Answer: Homeotic gene

Question:  Method of DNA replication in which two strands of DNA separate and synthesise new strands, is

• a) Semi conservative
• b) Non conservative
• c) Conservative
• d) Dispersive

Answer: Semi conservative

Question: In negative operon

• a) Co-repressor binds with repressor
• b) Co-repressor binds with inducer
• c) Co-repressor does not bind with repressor
• d) cAMP have negative effect on lac operon

Answer:  Co-repressor binds with repressor

Question: Gene and cistron words are sometimes used synonymously because

• a) One gene contains one cistron
• b) One gene contains many cistrons
• c) One gene contains no cistron
• d) One cistron contains many genes

Answer: One gene contains one cistron

Question: m-RNA is synthesised on DNA template in which direction?

• a)

  

• b)

  

• c) Both
• d) Any of these

Answer:

Question: At the time of organogenesis, genes regulate the process at different levels and at different time due to

• a) Exon
• b) Intron
• c) Regulator
• d) Promoter

Answer: Exon

Question:

• a) Both strains have different cistrons
• b) It is not mutated
• c) Bacteriophage transforms in wild
• d) Both strains have similar cistrons

Answer:  Both strains have different cistrons

Question: In E. coli, during lactose metabolism repressor binds to

• a) Operator gene
• b) Structural gene
• c) Promoter gene
• d) Regulator gene

Answer: Operator gene

Question: In a DNA, percentage of thymine is 20% then what will be percentage of guanine?

• a) 30%
• b) 60%
• c) 40%
• d) 20%

Answer:  30%

Question: Out of 64 codons, 61 codons code for 20 types of amino acid. It is called

• a) Degeneracy of genetic code
• b) Wobbling of codons
• c) Overlapping of genes
• d) Universality of codons

Answer: Degeneracy of genetic code

Question: Jacob and Monad studied lactose metabolism in E. coli and proposed operon concept. Operon concept is applicable for

• a) All prokaryotes
• b) All prokaryotes and all eukaryotes
• c) All prokaryotes and some eukaryotes
• d) All prokaryotes and some protozoans

Answer: All prokaryotes

Question: Exon part of hn-RNA have code for

• a) Protein
• b) Lipid
• c) Carbohydrate
• d) Phospholipid

Answer: Protein

Question: Which form of RNA has a structure resembling with clover leaf?

• a) tRNA
• b) None of these
• c) rRNA
• d) hn-RNA

Answer: tRNA

Question: Which of the following reunites the exon segments after RNA splicing?

• a) RNA ligase
• b) RNA proteoses
• c) RNA primase
• d)  RNA polymerase

Answer:  RNA ligase

Question: During initiation of translation in prokaryotes, a GTP molecule is needed in

• a) Association of 30 S mRNA with formyl-met-tRNA
• b) Binding of 30 S subunit of ribosome with mRNA
• c) Formation of formyl-met-tRNA
• d) Association of 50 S subunit of ribosome with initiation complex

Answer: Association of 30 S mRNA with formyl-met-tRNA

Question: In the genetic code dictionary, how many codons are used to code for all the 20 essential amino acids?

• a) 61
• b) 60
• c) 64
• d) 20

Answer: 61

Question:  The telomeres of eukaryotic chromosomes consist of short sequences of

• a) Guanine rich repeats
• b) Cytosine rich repeats
• c) Thymine rich repeats
• d) Adenine rich repeats

Answer: Guanine rich repeats

Question: What does “lac” refer to in what we call the lac operon?

• a) Lactose
• b) Lactase
• c) Lac insect
• d) The number 1,00,000

Answer: Lactose

Question: Degeneration of a genetic code is attributed to the

• a) Third member of a codon
• b) Second member of codon
• c) First member of a codon
• d) Entire codon

Answer: Third member of a codon

Question: During transcription, the DNA site at which RNA polymerase binds is called

• a) Promoter
• b) Regulator
• c) Receptor
• d) Enhancer

Answer: Promoter

Question: What would happen if in a gene encoding a polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA ?

• a) A polypeptide of 24 amino acids will be formed
• b) Two polypeptides of 24 and 25 amino acids will be formed
• c) A polypeptide of 25 amino acids will be formed
• d) A polypeptide of 49 amino acids will be formed

Answer: A polypeptide of 24 amino acids will be formed

Question: Which one of the following triplet codon, is correctly matched with its specificity for an amino acid in protein synthesis or as ‘start’ or ‘stop’ codon ?

• a) UAC - tyrosine
• b) UGU – leucine
• c) UUU - stop
• d) UCG - start

Answer: UAC - tyrosine

Question: DNA fingerprinting refer to

• a) Molecular analysis of profiles of DNA samples
• b) Analysis of DNA samples using imprinting devices
• c) Techniques used for molecular analysis of different specimens of DNA
• d) Techniques used for identification of fingerprints of individuals

Answer: Molecular analysis of profiles of DNA samples

Question: 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

• a) UAUGC
• b) UATGC
• c) TATGC
• d) TCTGG

Answer:  UAUGC

Question: After a mutation at a genetic locus the character of an organism changes due to change in

• a) Protein structure
• b) Protein synthesis pattern
• c) DNA replication
• d)  RNA transcription pattern

Answer: Protein structure

Question: During replication of a bacterial chromosome DNA synthesis starts from a replication origin site and

• a) Moves in bi-directional way
• b) Is facilitated by telomerase
• c) RNA primers are involved
• d) Moves in one direction of the site

Answer: Moves in bi-directional way

Question: The following ratio is generally constant for a given species

• a) G + C / A + T
• b) A + C / T + G
• c) T + C / G + A
• d) A + G / C + T

Answer: G + C / A + T

Question: What is true for E. coli with inhibited lac-z gene?

• a) They cannot synthesize functional beta galactosidase
• b) They cannot synthesize permease
• c) They cannot synthesize transacetylase
• d) They cannot transport lactose from the medium into the cell

Answer:  They cannot synthesize functional beta galactosidase

Question: Which antibiotic inhibits interaction between tRNA and mRNA during bacterial protein synthesis?

• a) Neomycin
• b) Streptomycin
• c)  Erythromycin
• d) Tetracycline

Answer: Neomycin

Question: During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle - like structure. What is it’s DNA-binding sequence?

• a) TATA
• b) TTAA
• c) CACC
• d) AATT

Answer: TATA

Question: Differentiation of organs and tissues in a developing organism, is associated with

• a) Differential expression of genes
• b) Deletion of genes
• c) Lethal mutations
• d) Developmental mutations

Answer:  Differential expression of genes

Question: The nuclease enzyme, which begins its attack from free end of a polynucleotide, is

• a) Exonuclease
• b) Kinase
• c) Endonuclease
• d) Polymerase

Answer: Exonuclease

Question: Radio-tracer technique shows that DNA is in

• a) Double-helix stage
• b) None of these
• c) Single-helix stage
• d) Multi-helix stage

Answer: Double-helix stage

Question: Genes are packaged into a bacterial chromosome by

• a) Basic protein
• b) Histones
• c) Actin
• d) Acidic protein

Answer: Basic protein

Question: The hereditary material present in the bacterium E.coli is

• a) Double-stranded DNA
• b) RNA
• c) Single-stranded DNA
• d) DNA and RNA

Answer:  Double-stranded DNA

Question: The Pneumococcus experiment proves that

• a) DNA is the genetic material
• b) Bacteria undergo binary fission
• c) RNA sometime controls the production of DNA and proteins
• d) Bacteria do not reproduce sexually

Answer: DNA is the genetic material

Question: E.coli about to replicate was placed in a medium containing radio active thymidine for five minutes. Then it was made to replicate in a normal medium. Which of the following observation shall be correct?

• a) One strand radioactive
• b) None is radioactive
• c) Both the strands of DNA will be radioactive
• d) Each strand half radioactive

Answer: One strand radioactive

Question: Types of RNA polymerase required in nucleus of eukaryotes for RNA synthesis is/are

• a) 3
• b) 4
• c) 2
• d) 1

Answer: 3

Question: Transformation experiment was first performed on which bacteria?

• a) Diplococcus pneumoniae
• b) Pasteurella pestis
• c) E. coli
• d) Salmonella

Answer: Diplococcus pneumoniae

Question: Telomerase is an enzyme which is a

• a) Ribonucleoprotein
• b) Repetitive DNA
• c) RNA
• d) Simple protein

Answer: Ribonucleoprotein

Question: In transgenics, expression of transgene in target tissue is determined by

• a) Promoter
• b) Reporter
• c) Transgene
• d) Enhancer

Answer: Promoter

Question: A nutritionally wild type organism, which does not require any additional growth supplement, is known as

• a) Prototroph
• b) Auxotroph
• c) Mixotroph
• d) Osmotroph

Answer: Prototroph

Question: What is not true for genetic code?

• a) A codon in mRNA is read in a non-contiguous fashion
• b) It is unambiguous
• c) It is nearly universal
• d) It is degenerate

Answer: A codon in mRNA is read in a non-contiguous fashion

Question: Semiconservative replication of DNA was first demonstrated in

• a) Escherichia coli
• b) Salmonella typhimurium
• c) Drosophila melanogaster
• d) Streptococcus pneumoniae

Answer:  Escherichia coli

Question: Which one of the following statements about the particular entity is true?

• a) The gene for producing insulin is present in every body cell
• b) Centromere is found in animal cells, which produces aster during cell division
• c) DNA consists of a core of eight histones
• d) Nucleosome is formed of nucleotides

Answer: The gene for producing insulin is present in every body cell