NEET Biology Molecular Basis of Inheritance MCQs Set D

Question: Identification and binding of RNA polymerase to the promoter sequence is a function of

• a) Sigma factor
• b) Beta factor
• c) Omega factor
• d) Rho factor

Answer: Sigma factor

Question: Repetitive sequences are stretches of DNA with repeated bases many times in a genome, but

(a) These sequences are of no transcriptional function
(b) These are associated with euchromatin region
(c) These helps to identify a person on the basis of its DNA specificity

• a) Only (b) is incorrect
• b) Both (b) & (c) are incorrect
• c) All are correct
• d) Both (a) & (b) are correct

Answer: Only (b) is incorrect

Question: The microsatellites have simple sequences of repeated

• a) 1-6 bp
• b)  10 bp
• c) 50 bp
• d) 11-60 bp

Answer: 1-6 bp

Question:  The DNA strand showing replication using Okazaki fragments also shows

• a)

  

• b)

  

• c)

  

• d) Involvement of one primer only

Answer:

Question: Prokaryotic transcription mechanism requires involvement of only one polymerase type and

(a) It occurs in cytoplasm only
(b) It is often coupled with translation
(c) It does not require splicing but capping is essential

• a) Only (c) is incorrect
• b) Both (b) & (c) are incorrect
• c) All are correct
• d) Both (a) & (c) are correct

Answer: Only (c) is incorrect

Question: Pribnow box is a consensus of ________ bases, forming a binding site for E. coli RNA polymerase at promotor

• a) TATAAT
• b) AGGAGG
• c) CAAT
• d) GC

Answer: TATAAT

Question: In tryptophan operon

• a) Enzymes produced by structural genes normally present in the cell
• b) Repression is mostly connected with a catabolic pathway
• c) Normally chorismic acid is not converted into tryptophan
• d) Non-proteinaceous aporepressor is synthesised by R-gene

Answer: Enzymes produced by structural genes normally present in the cell

Question: In tailing, adenylate residues are added at 3′ end

• a) In a template independent manner
• b) Of hn-RNA of E.coli
• c) With the help of gyanyl transferase
• d) With the help of methyl transferase

Answer:   In a template independent manner

Question: For every single amino acid incorporated in peptide chain _____ ATP and _____ GTP molecules are used

• a) 1, 2
• b) 1, 3
• c) 1, 6
• d) 1, 4

Answer: 1, 2

Question: In t-RNA

• a) DHU loop for binding with AA - activating enzyme
• b) CCA – OH is present at 5-end
• c) There are three recognition sites
• d) None of these

Answer: DHU loop for binding with AA - activating enzyme

Question: Identify the correct order of organisation of genetic material from largest to smallest

• a) Genome, chromosome, gene, nucleotide
• b) Chromosome, gene, genome, nucleotide
• c) Chromosome, genome, nucleotide, gene
• d) Genome, chromosome, nucleotide, gene

Answer: Genome, chromosome, gene, nucleotide

Question: Satellite DNA is important because it

• a) Shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children
• b) Does not code for proteins and is same in all members of the population
• c) Codes for proteins needed in cell cycle
• d) Codes for proteins needed in cell cycle

Answer: Shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children

Question: Gene regulation governing lactose operon of E.coli that involves the lac I gene product is

• a) Negative and inducible because repressor protein prevents transcription
• b) Positive and inducible because it can be induced by lactose
• c) Negative and repressible because repressor protein prevents transcription
• d) None of these

Answer: Negative and inducible because repressor protein prevents transcription

Question: Which one of the followings is wrongly matched?

• a)  Operon-Structural genes, operator and promoter
• b) Repressor protein-Binds to operator to stop enzyme synthesis
• c) Translation-Using information in m-RNA to make protein
• d) Transcription- Writing information from DNA to t-RNA

Answer: Operon-Structural genes, operator and promoter

Question:  Select the correct option

• a)

  

  

• b)

  

  

• c)

  

  

• d) None of these

Answer:

Question: Transformation was discovered by

• a) Griffith
• b) Meselson and Stahl
• c) Hershey and Chase
• d) Watson and Crick

Answer: Griffith

Question: Which enzyme/s will be produced in a cell in which there is a nonsense mutation in the lac Y gene?

• a)

  

• b) Transacetylase
• c) Lactose permease
• d) Lactose permease and transacetylase

Answer:  

Question: The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C.

• a) A-transcription, B-translation, C-Francis Crick
• b) A-transcription, B-replication, C-James Watson
• c) A-translation, B-transcription, C-Erevin Chargaff
• d) A-translation, B-extension, C-Rosalind Franklin

Answer: A-transcription, B-translation, C-Francis Crick

Question: Removal of RNA polymerase III from nucleoplasm will affect the synthesis of

• a) tRNA
• b) hnRNA
• c) rRNA
• d) mRNA

Answer:  tRNA

Question: Removal of introns and joining of exons in a defined order during transcription is called

• a) Splicing
• b) Looping
• c) Inducing
• d) Slicing

Answer: Splicing

Question: Which one of the following is not a part of a transcription unit in DNA?

• a) The inducer
• b) A terminator
• c) The structural gene
• d) A promoter

Answer: The inducer

Question: If one strand of DNA has the nitrogenous base sequence as ATCTG, what would be the complementary RNA strand sequence?

• a) UAGAC
• b) TTAGU
• c) ATCGU
• d) AACTG

Answer:  UAGAC

Question:  Read the following four statements (A-D)

(A) In transcription, adenosine pairs with uracil
(B) Regulation of lac operon by repressor is referred to as positive regulation
(C) The human genome has approximately 50,000 genes
(D) Haemophilia is a sex-linked recessive disease
How many of the above statements are right?

• a) Two
• b) Three
• c) Four
• d) One

Answer: Two

Question: PCR and Restriction Fragment Length Polymorphism are the methods for

• a) Genetic fingerprinting
• b) Genetic transformation
• c) DNA sequencing
• d) Study of enzymes

Answer: Genetic fingerprinting

Question: What is it that forms the basis of DNA fingerprinting?

• a) Satellite DNA occurring as highly repeated short DNA segments
• b) The relative proportions of purines and pyrimidines in DNA
• c) The relative difference in the DNA occurrence in blood, skin and saliva
• d) The relative amount of DNA in the ridges and grooves of the fingerprints

Answer:  Satellite DNA occurring as highly repeated short DNA segments

Question: Which one of the following also acts as a catalyst in a bacterial cell?

• a) 23 S rRNA
• b) 5 S rRNA
• c) sn RNA
• d) hn RNA

Answer: 23 S rRNA

Question: What are those structures that appear as 'beads – on – string' in the chromosomes when viewed under electron microscope?

• a) Nucleosomes
• b) Nucleotides
• c) Genes
• d) Base pairs

Answer: Nucleosomes

Question: In history of biology, human genome project led to the development of

• a) Bioinformatics
• b) Biosystematics
• c) Biotechnology
• d) Biomonitoring

Answer: Bioinformatics

Question: The unequivocal proof of DNA as the genetic material came from the studies on a

• a) Bacterial virus
• b) Bacterium
• c) Fungus
• d) Viroid

Answer: Bacterial virus

Question: Which one of the following does not follow the central dogma of molecular biology?

• a) HIV
• b) Pea
• c) Mucor
• d) Chlamydomonas

Answer:  HIV

Question: Select the two correct statements out of the four (a–d) given below about lac operon

(a) Glucose or galactose may bind with the repressor and inactivate it.
(b) In the absence of lactose the repressor binds with the operator region.
(c) The z-gene codes for permease.
(d) This was elucidated by Francois Jacob and Jacque Monod.

The correct statements are

• a) (b) and (d)
• b) (a) and (c)
• c) (b) and (c)
• d) (a) and (b)

Answer: (b) and (d)

Question: The one aspect which is not a salient feature of genetic code, is its being

• a) Ambiguous
• b) Universal
• c) Degenerate
• d) Specific

Answer: Ambiguous

Question: In eukaryotic cell transcription, RNA splicing and RNA capping take place inside the

• a) Nucleus
• b) Dictyosomes
• c) ER
• d) Ribosomes

Answer: Nucleus

Question: The lac operon consists of

• a) One regulatory gene and three structural genes
• b) Three regulatory genes and three structural genes
• c) Four regulatory genes only
• d) Two regulatory genes and two structural genes

Answer:  One regulatory gene and three structural genes

Question:

• a) One nucleotide with another nucleotide
• b) One DNA strand with the other DNA strand
• c) One nucleoside with another nucleoside
• d) None of these

Answer: One nucleotide with another nucleotide

Question: Satellite DNA is useful tool in

• a) Forensic science
• b) Organ transplantation
• c) Genetic engineering
• d) Sex determination

Answer: Forensic science

Question: Removal of introns and joining the exons in a defined order in a transcription unit is called

• a) Splicing
• b) Capping
• c) Transformation
• d) Tailing

Answer:  Splicing

Question: Semiconservative replication of DNA was first demonstrated in

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

Answer: Escherichia coli

Question: What is not true for genetic code?

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

Answer:  A codon in mRNA is read in a noncontiguous fashion

Question: Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a "triplet"?

• a) Nirenberg and Mathaei
• b) Morgan and Sturtevant
• c) Hershey and Chase
• d) Beadle and Tatum

Answer: Nirenberg and Mathaei

Question: Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it?

• a) Adenine, Thymine - Purines
• b) Uracil, Cytosine - Pyrimidines
• c) Thymine, Uracil - Pyrimidines
• d) Guanine, Adenine - Purines

Answer: Adenine, Thymine - Purines

Question:  In the DNA molecules

• a)

  

• b) The total amount of purine nucleotides and pyrimidine nucleotides is not always equal
• c) The proportion of adenine in relation to thymine varies with the organism
• d) There are two strands which run parallel

Answer:  

Question: Which one of the following pairs of codons is correctly matched with their function or the signal for the particular amino acid?

• a) UAG, UGA - Stop
• b) UUA, UCA - Leucine
• c) GUU, GCU - Alanine
• d) AUG, ACG - Start / Methionine

Answer: UAG, UGA - Stop

Question: One gene-one enzyme relationship was established for the first time in

• a) Neurospora crassa
• b) Escherichia coli
• c) Diploccus pneumoniae
• d) Salmonella typhimurium

Answer: Neurospora crassa

Question: A sequential expression of a set of human genes occurs when a steroid molecule binds to the

• a) DNA sequence
• b) Messenger RNA
• c) Transfer RNA
• d) Ribosome

Answer:  DNA sequence

Question:  The Okazaki fragments in DNA chain growth

• a)

  

• b) Result in transcription
• c) None of these
• d) Proove semi-conservative nature of DNA replication

Answer:

Question: Molecular basis of organ differentiation depends on the modulation in transcription by

• a) Transcription factor
• b) Ribosome
• c) RNA polymerase
• d) Anticodon

Answer: Transcription factor

Question: Telomere repetitive DNA sequence control the function of eukaryote chromosomes because they

• a) Prevent chromosome loss
• b) Are RNA transcription initiator
• c) Act as replicons
• d) Help chromosome pairing

Answer: Prevent chromosome loss

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

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

Answer: TATA

Question: The two polynucleotide chains in DNA are [

• a) Antiparallel
• b) Discontinuous
• c) Parallel
• d) Semiconservative

Answer: Antiparallel

Question: The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?

• a) Super-coiling in nucleosomes
• b) Through elimination of repetitive DNA
• c) Deletion of non-essential genes
• d) DNAse digestion

Answer: Super-coiling in nucleosomes

Question: One turn of the helix in a B-form DNA is approximately

• a) 3.4 nm
• b) 2 nm
• c) 0.34 nm
• d) 20 nm

Answer: 3.4 nm

Question: Antiparallel strands of a DNA molecule means that

• a) The phosphate groups at the start of two DNA strands are in opposite position (pole)
• b) The phosphate groups of two DNA strands, at their ends, share the same position
• c) One strand turns anti-clockwise
• d) One strand turns clockwise

Answer: The phosphate groups at the start of two DNA strands are in opposite position (pole)

Question: Amino acid sequence, in protein synthesis is decided by the sequence of

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

Answer: m-RNA

Question: One gene – one enzyme hypothesis was postulated by

• a) Beadle and Tatum
• b) A. Garrod
• c) Hershey and Chase
• d) R. Franklin

Answer: Beadle and Tatum

Question: During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called?

• a) TATA box
• b) AAAT box
• c) GGTT box
• d) CAAT box

Answer: TATA box

Question: E. coli cells with a mutated Z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because

• a) They cannot synthesize functional â-galactosidase
• b) The lac operon is constitutively active in these cells
• c) They cannot transport lactose from the medium into the cell
• d) In the presence of glucose, E. coli cells do not utilize lactose

Answer:  They cannot synthesize functional â-galactosidase

Question: Nucleotide are building blocks of nucleic acids, nucleotide is a composite molecule formed by

• a) ase-sugar-phosphate
• b) Base-sugar-OH
• c) Sugar-phosphate
• d) (Base-sugar-phosphate)_n

Answer: ase-sugar-phosphate

Question: Which one of the following makes use of RNA as a template to synthesize DNA?

• a) Reverse transcriptase
• b) DNA polymerase
• c) DNA dependant RNA polymerase
• d) RNA polymerase

Answer: Reverse transcriptase

Question: Uridine, present only in RNA is a

• a) Nucleoside
• b) Nucleotide
• c) Purine
• d) Pyrimidine

Answer:  Nucleoside