In his experiment on the chemistry of DNA, Chargaff estimated the base composition of human sperms and found Adenine is 19%, then the amount of Thymine in somatic cell will be

  • 19%

  • 31%

  • 38%

  • 62%

Semi-conservative nature of the replication of eukaryotic chromosome was experimentally demonstrated by

  • Chains

  • Meselson and Stahl

  • Hebert Taylor

  • Hershey and Chase

The short fragment of DNA produced in the lagging strand during duplication is known as

  • Okazaki fragments

  • RNA primer

  • Leading strand

  • Recombinant DNA

How many times can the nuclear DNA replicate during the life cycle of a cell?

  • Only once

  • Twice

  • Many times

  • Does not replicate at all

The number of autosomal chromosomes in the human beings are

  • 44

  • 22

  • 2

  • 1

In DNA replication, the two strands of a daughter DNA molecules are derived as follows

  • one strand from parent DNA and the other freshly synthesized

  • both strands from parent DNA

  • both strands synthesized as templates on parent strands

  • both strands synthesized on RNA templates of parent strands

DNA replication in most organisms is

  • conservative and continuous

  • semi-conservative but discontinuous

  • semi-conservative and semi-discontinuous

  • semi-conservative but continuous

Borne viruses do not have DNA. This suggests that

  • They are non-infective viruses

  • RNA is the genetic material in these viruses

  • DNA is not the genetic material

  • RNA is a self replicating molecule

The central dogma is

  • Direction of flow of information from DNA→RNA→proteins

  • the transfer of genetic information from same strand of DNA to m-RNA

  • The faithful transfer of genetic information from DNA molecule to the next generation molecule through semi conservative mechanism

  • Mendelism has established the principles of heredity

The core enzyme which requires the factor for termination of RNA synthesis at some sites is known as

  • Sigma factor

  • Rho factor

  • Gamma factor

  • Alpha particle

In a DNA% of T is 20% then what will be the % of G?

  • 20%

  • 40%

  • 30%

  • 60%

Role of DNA in heredity was discovered for the first time through experiments involving

  • Transformation using E.coli

  • Transduction involving bacteriophage

  • The use of enzymes protease and nuclease

  • Transformation using heat killed virulent and living non virulent S.pneumoniae

In 125 amino acids, sequence of the codon for 25th amino acid is mutated to UAA, then

  • A polypeptide of 24 amino acids is formed

  • A polypeptide of 124 amino acids is formed

  • A polypeptide of 25 amino acids is formed

  • No polypeptides are formed

If length of DNA is 1.36 mm , the number of base pair and nucleosomes in it will be

  • 4×10^12 and 2×10^4

  • 4×10^6 and 2×10^10

  • 4×10^6 and 2×10^4

  • 4×10^6 and 2×10^12

If a codon consists of 3 bases and there are 5 different nitrogenous bases altogether. How many codons will be there?

  • 61

  • 125

  • 27

  • 64

If a DNA have 5000 bases , and amount of adenine is 15% then find out the number of nucleotide of guanine

  • 1750

  • 3500

  • 7000

  • 975

A codon consists of three nitrogenous bases and there are four kind of bases in nucleic acid altogether. How many codons will be there?

  • 60

  • 43

  • 34

  • 46

The main enzyme for DNA replication is

  • DNA-dependent RNA polymerase

  • RNA-dependent DNA polymerase

  • DNA-dependent DNA polymerase

  • RNA-dependent RNA polymerase

The energy for the DNA replication comes from

  • Deoxyribonucleosides triphosphates

  • Deoxyribonucleotides triphosphates

  • Deoxyribonucleosides

  • phosphorylation of ATP

Which of the following is incorrect for DNA polymerase?

  • template dependent enzyme

  • highly efficient enzyme

  • high degree of accuracy

  • template independent enzyme

which of the following purposes are not served by Deoxyribonucleoside triphosphates

  • act as substrate

  • act as energy source for replication

  • act as enzyme cofactors

  • act same as ATP

The small opening of the DNA helix where replication occurs is known as

  • replication centre

  • replication opening

  • replication fork

  • duplication fork

The template of DNA on which discontinuous replication occurs has polarity

(1)5’to 3’

(2)3’ to 5’

(3)both a and b

(4)None of these
  • 1
  • 2
  • 3
  • 4

The discontinuously synthesised fragments are joined later by

  • DNA polymerase III

  • DNA ligase

  • DNA gyrase

  • DNA polymerase I

In eukaryotes, the replication of DNA takes place

  • at S-phase of the cell cycle

  • before G2 and after G1phase of the cell cycle

  • at M phase

  • Both a and b

If cell division wouldn't occur after DNA replication then cell will have

  • chromosomal abberation

  • polyploidy

  • chromosomal anomaly

  • Both b and c

Which principle govern the principle of transcription?

  • (a)Cleavage of phosphodiester bond

  • (b)Phosphorylation

  • (c)Complementarity

  • ()duplication

Which of the following statement is not true ?

(1)In replication the total DNA of an organism gets duplicated

(2)In transcription complete one strand of the DNA gets copied

(4)Both b and c
  • 1
  • 2

  • (3) In transcription only a segment of only one strands of the DNA gets copied

  • 4

Why both the strands of DNA are not copied during transcription because

  • RNA molecules with different sequences will be produced and hence proteins with different sequences will be produced.

  • double stranded RNA molecules will be produced that would prevent translation of dsRNA

  • cell will fail to produce proteins as no single stranded RNA is present

  • All of the above

 Which of the following is not a unit of transcription unit

  • A promoter

  • The structural gene

  • A terminator

  • A operator

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