GENETICS

SET -1

Question 1

PCR and Restriction Fragment Length Polymorphism are the methods for

A	DNA sequencing
B	Genetic fingerprinting
C	Study of enzymes
D	Genetic transformation

Question 2

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

A	mRNA
B	rRNA
C	tRNA
D	hnRNA

Question 3

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

A	Slicing
B	Splicing
C	Looping
D	Inducing

Question 4

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

A	A promoter
B	The structural gene
C	The inducer
D	A terminator

Question 5

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

A	Plasmid
B	Probe
C	Vector
D	Selectable marker

Question 6

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

A	AACTG
B	ATCGU
C	TTAGU
D	UAGAC

Question 7

Degeneracy of genetic code is due to

A	functional 61 codons and 20 amino acids
B	functional 64 codons and 20 amino acids
C	functional 20 codons and 20 amino acids
D	functional 20 codons and 61 amino acids

Question 8

Why are UGA, UAG and UAA called termination codons?

A	They do not specify any amino acid
B	They are present at the beginning of mRNA
C	They terminate anticodons
D	They indicate initiation of translation

Question 9

During replication of DNA,Okazakifragments are formed in the direction of :

A	3′→5′
B	5′→3′
C	5′→5′
D	3′→3′

Question 10

Link together two pieces of DNA

A	Link together two pieces of DNA
B	Cut DNA at specific locations
C	Restrict elongation of DNA
D	Restrict DNA replication

Question 11

In the DNA molecule:

A	The proportion of Adenine in relation to thymine varies with the organism
B	There are two strands which run parallel in the 5′ → 3′ direction
C	There are two strands which run antiparallel-one in 5′ → 3′ direction and other in 3′ → 5′
D	The total amount of purine nucleotides and pyrimidine nucleotides is not always equal

Question 12

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	A polypeptide of 25 amino acids will be formed
C	A polypeptide of 49 amino acids will be formed
D	Two polypeptides of 24 and 25 amino acids will be formed

Question 13

Number of nitrogenous bases in a Codon is

A	3
B	2
C	1
D	5

Question 14

A gene of operon which synthesizes a repressor protein is ______.

A	Promoter gene
B	Regulator gene
C	Operator gene
D	Structural gene

Question 15

The sequence of events mentioned below are symbolized by alphabets. Choose the correct answer where the alphabets are matched with the processes. <.p>

RNA —(A)—> DNA —(B)—> DNA —(C)—> mRNA —(D)—> Polypeptide

A	A = Replication, B = Transformation, C = Transcription, D = Translation
B	A = Reverse transcription, B = Translation, C = Transcription, D = Replication
C	A = Replication, B = Transcription, C = Translation, D = Transduction
D	A = Reverse transcription, B = Replication, C = Transcription, D = Translation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     SET 2 Question 1 All the terminator codons begin with the nucleotide of A Adenine B Uracil C Guanine D Cytosine Question 2 In the synthesis of which of the following, the DNA molecule is not directly involved? A mRNA molecule B protein molecule C another DNA molecule D tRNA molecule Question 3 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 Question 4 The transcription of any gene is the indication of its A Induction B Activity C Stimulation D Hypersensitivity Question 5 Signaling between cells usually results in the activation of protein A Lipases B Kinases C Proteases D Nucleases Question 6 A phenomenon where the third base of t-RNA at its 5’ end can pair with a non-complementary base of m-RNA is called A Degeneracy B Wobbling C Universality D Collinearity Question 7 During translation initiation in prokaryotes, a GTP molecule is needed in A association of 30S, mRNA with formyl-met-t RNA B association of 50S subunit of ribosome with initiation complex C formation of formyl-met-tRNA D binding of 30 subunit of ribosome with mRNA Question 8 Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a ‘‘triplet’’? A Beadle and Tatum B Nirenberg and Matthaei C Hershey and Chase D Morgan and Sturtevant Question 9 Molecular basis of organ differentiation depends on the modulation in transcription by A Anticodon B RNA polymerase C Ribosome D Transcription factor Question 10 The sequence of structural gene in lac operon concept is A lac Y, lac Z, lac A B lac Z, lac Y, lac A C lac A, lac Y, lac Z D lac A, lac Z, lac Y Question 11 The sequence of nitrogen bases in a particular region of the noncoding strand of a DNA molecule was found to be CAT GTT TAT CGC. What would be the sequence of nitrogen bases in the mRNA that is synthesized by the corresponding region of the coding strand in that DNA? A GUA CAA AUA GCC B GTA CAA ATA GCC C CAU GUU UAU CGG D CAA GAA TAU GCC Question 12 Protein synthesis in an animal cell occurs A On ribosomes presents in cytoplasm as well as in mitochondria B On ribosomes present in the nucleolus as well as in cytoplasm C Only on ribosomes attached to the nuclear envelope and endoplasmic reticulum D Only on the ribosomes present in cytosol Question 13 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 beta galactosidase B They cannot transport lactose from the medium into the cell C The lac operon is constitutively active in these cells D In the presence of glucose, E. coli cells do not utilize lactose Question 14 Production of a human protein in bacteria by genetic engineering is possible because A Bacterial cell can carry out the RNA splicing reactions B The mechanism of gene regulation is identical in humans and bacteria C The human chromosome can replicate in bacterial cell D The genetic code is universal Question 15 Assertion:  Replication  and  transcription  occur  in  the  nucleus  but  translation  occurs  in  the cytoplasm. Reason: mRNA is transferred from the nucleus into the cytoplasm where ribosomes and amino acids are available for protein synthesis. A Both Assertion and Reason are true and the Reason is the correct explanation of the Assertion. B Both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion. C Assertion is true statement but Reason is false. D Both Assertion and Reason are false statements.  SET - 3  Question 1 During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle-like structure. What is its DNA-binding sequence? A TATA B TTAA C AATT D CACC Question 2 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 TCTGG B UAUGC C UATGC D TATGC Question 3 During protein synthesis, AUG functions as the initiator codon in mRNA. What should be the anticodon on the tRNA molecule that picks up and brings the amino acid specified by this codon? A TAC B UAC C GUA D CAU Question 4 Which one of the following pairs is correctly matched with regard to the codon and the amino acid coded by it? A UUA-Valine B AAA-Lysine C AUG-Cysteine D CCC-Alanine Question 5 According to the lac-operon concept, which functional unit of the bacterial gene material is responsible for suppressing the activity of the operator gene in the absence of lactose? A Promoter gene B Repressor protein C Regulator gene D Structural gene Question 6 In a DNA strand the nucleotides are held together by: A Peptide bonds B Phosphodiester bonds C Glycosidic bonds D Hydrogen bonds Question 7 The reaction, Amino acid + ATP → Aminoacyl-AMP + P–P depicts A Amino acid assimilation B Amino acid transformation C Amino acid activation D Amino acid translocation Question 8 mRNA directs the building of proteins through a sequence of A Introns B Codons C Exons D Anticodons Question 9 Enzyme responsible for reverse transcription is : A Reverse transcriptase B DNA polymerase C RNA polymerase D RNA dependent RNA polymerase Question 10 DNA has equal number of adenine and thymine residues (A = T) and equal number of guanine and cytosine (G = C). These relationships are known as A Chargaff's rule B Coulomb's law C Le-Chatelier's principle D Van't Hoff plot Question 11 Central dogma of protein synthesis is A DNA → RNA → Protein B DNA → DNA → Protein C RNA → DNA → Protein D DNA → protein → RNA Question 12 There are 64 codons in the genetic dictionary as A There are 64 amino acids to be coded B Genetic code has a triplet nature C There are 3 nonsense codons and 61 sense codons D There are 64 different types of t-RNA Question 13 Which one of the following does not follow the central dogma of molecular biology? A HIV B Pea C Mucor D Chlamydomonas Question 14 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 statement are A (a) and (b) B (b) and (c) C (a) and (c) D (b) and (d) Question 15 Assertion: Amber codon is a termination codon. Reason: If in a mRNA, a termination codon is present, the protein synthesis stops abruptly whether the protein synthesis is complete or not. A Both Assertion and Reason are true and Reason is the correct explanation of the Assertion. B Both Assertion and Reason are true but the Reason is not the correct explanations of Assertion. C Assertion is true, but Reason is false. D Both Assertion and Reason are false