VNTR are useful in DNA profiling because they:

I. Are hypervariable

II. Are inherited

III. Synthesize constitutive enzymes

  • I, II, III are correct

  • I and II are correct

  • I and III are correct

  • II and III are correct   

Which enzyme polymerizes RNA with defined sequences in a template independent manner?

  • Peptidyl transferase

  • RNA polymerase

  • Reverse transcriptase

  • Polynucleotide phosphorylase

The process of RNA splicing shows the dominance of :

  • DNA world

  • RNA world

  • Protein world

  • Microbial world

In RNA splicing :

  • Exons are removed and introns are joined together

  • Introns are removed and exons are joined together

  • Cistrons are removed and introns are joined together

  • Introns are removed and Cistrons are joined together

The core RNA polymerase is capable of catalyzing which steps of transcription ?

  • Initiation only

  • Elongation only

  • Termination only

  • All of these

In most prokaryotes the transcription unit is :

  • Mono-cistronic

  • Poly-cistronic

  • Multi-cistronic

  • Uni-cistronic

The DNA dependent DNA polymerases catalyze:

  • Only in 3'-5' direction

  • Only in 5'-3' direction

  • In both directions

  • In neither directions

Reverse transcriptase is a:

  • DNA dependent RNA polymerase

  • RNA dependent DNA polymerase

  • RNA dependent RNA polymerase

  • DNA dependent DNA polymerase

A molecule that can act as a genetic material must fulfill all the following criteria except :

  • It should be able to generate its replica

  • It should chemically and structurally be stable

  • It should provide scope for rapid mutations

  • It should be able to express itself in the form of "Mendelian Characters"

The unequivocal proof that DNA is the genetic material was provided by :

  • Avery, Macleod and McCarty

  • Hershey and Chase

  • Meselson and Stahl

  • Watson and Crick

Which of the following is not a feature of the double helix model of DNA ?

  • The two chains have anti-parallel polarity

  • A purine always comes opposite to a pyrimidine

  • The pitch of the DNA is 3.4 nm

  • The two chains are coiled in a left handed fashion

According to Erwin Chargaff, for a double stranded DNA

  • The ratios between Adenine and Thymine, and, Guanine and Cytosine are constant and equals one. 

  • The ratios between Adenine and Thymine, and, Guanine and Cytosine are constant but is not equal to one. 

  • The ratios between Adenine and Guanine, and,Thymine, and Cytosine are constant and equals one. 

  • The ratios between Adenine and Guanine, and, Thymine and, Cytosine are constant but is not equal to one. 

To form a nucleoside, a nitrogenous base is linked to a pentose sugar:

 

  • Through a P-Glycosidic linkage at carbon atom number 1

  • Through a P-Glycosidic linkage at carbon atom number 5

  • Through a N-Glycosidic linkage at carbon atom number 1

  • Through a N-Glycosidic linkage at carbon atom number 5

Which one of the following is not applicable to RNA ?

  • Complementary base pairing

  • 5' phosphoryl and 3' hydroxyl ends

  • Heterocyclic nitrogenous bases

  • Chargaff's rule

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

  • Chromosome, gene, genome, nucleotide

  • Genome, chromosome, nucleotide, gene

  • Genome, chromosome, gene, nucleotide

  • Chromosome, genome, nucleotide, gene

Satellite DNA is important because it

polymorphism in an individual, which is heritable from parents to children

  • codes for protiens needed in cell cycle

  • shows high degree of polymorphism in population and also the same degree of

  • does not code for protiens and is same in all members of the population

  • codes for enzymes needed for DNA replication.

Transformation was discovered by

  • Meselson and Stahl

  • Hershey and Chase

  • Griffith

  • Watson and Crick

Identify the incorrectly matched pair:

 

Organism

Length of DNA

Bacteriophage ϕ 174

5386 nucleotides

(2)

Bacteriophage Lambda   

(3)

Eschrechia coli

4×106  base pairs

(4)

Human beings

3.3×109  base pairs

 

  •   

  • 48502 base pairs

  • 3
  • 4

The amino acid acceptor arm of the tRNA is at its:

 

  • DHU loop

  • TψC loop

  • 5' end

  • 3' end

Which of the following codons has a dual role in the genetic code?

 

  • AUG

  • GUG

  • CUG

  • UUG

What is the major difference between the lagging and leading strands during DNA replication ?

 

  • On the leading strand, DNA synthesis occurs from 5' to 3', while DNA synthesis occurs from 3' to 5' on the lagging strand.

  • DNA polymerase is able to continuously add new nucleotides on the leading strand while it must keep 'starting over' on the lagging strand.

  • The lagging strand requires only a single primer while the leading strand requires many.

  • Helicase opens the leading stran at a faster rate than the lagging strand.

The inducer of lac operon is :

  • Beta galactosidase

  • Galactose

  • Lactose

  • Glucose

regulatory domains of most activators interact with

  • the transcription factor complex

  • RNA polymerase

  • repressors

  • the DNA binding domain

DNA chemically is less reactive and structurally more stable than RNA. Therefore,

  • DNA has evolved from the RNA

  • RNA can directly code for proteins

  • DNA is the better genetic material than RNA

  • The protein synthesizing machinery has evolved around RNA

A transcription unit does not contain:

  • A promoter

  • The structural gene

  • A terminator

  • An operator

Regulation of lac operon by repressor is referred to as:

  • Inducible regulation

  • Repressible regulation

  • Negative regulation

  • Positive regulation

A synthetic mRNA of repeating sequence 5'-CACACACACACACACAC... is used for a cell-free protein synthesizing system like the one used used by Nirenberg. If we assume that protein synthesis can begin without the need for an initiator codon, what product or products would you expect to occur after protein synthesis?

  • one protein, consisting of a single amino acid

  • three proteins, each consisting of a different, single amino acid

  • two proteins, each with an alternating sequence of two different amino acids

  • one protein, with an alternating sequence of two different amino acids

Fredrick Griffith accidentally discovered transformation when attempting to develop a vaccine for pneumonia. He injected mice with samples from S-strain (virulent) and/or R-strain (nonvirulent) pneumococci bacteria (Sterptococcus pneumoniae). Which of the following results is NOT consistent with Griffith's experiments?

  • injected S-strain; mouse dies. 

  • injected R-strain; mouse lives. 

  • injected heat-killed S-strain; mouse lives. 

  • injected mixture of heat-killed S-strain and live R-strain; mouse lives. 

Which scientists first gave experimental evidence that DNA is the genetic material?

  • Avery, MacLeod , and McCarty who repeated the transformation experiments of Griffith, and chemically characterized the transforming principle.

  • Garrod, who postulated that Alcaptonuria, or black urine disease, was due to a defective enzyme.

  • Beadle and Tatum, who used a mutational and biochemical analysis of the bread mold Neurospora to extablish a direct link between genes and enzymes. 

  • Meselson and Stahl who showed that DNA is replicated semiconservatively.

The function of the rho protein is 

  • to help terminate translation

  • to help RNA polymerase bind to the DNA

  • to help RNA polymerase find a promoter

  • to help terminate transcription

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