Multiple Choice Questions

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Assertion : Watson and Crick provided experimental proof of semiconservative nature of DNA replication.

Reason : DNA polymerase binds nucleotides in replication.

  • If both Assertion and Reason are true and Reason is the correct explantion of Assertion

  • If both Assertion and Reason are true and Reason is not the correct explanation of Assertion

  • If Assertion is true but Reason is false

  • If Assertion is false but Reason is true.


D.

If Assertion is false but Reason is true.

Watson and Crick suggested the double helical structure of DNA. Semiconservative nature of DNA replication was proved by Messelson and Stahl by using heavy isotope of nitrogen (15N).

DNA polymerase III establishes phosphodiester linkages between the adjacent deoxyribo-nucleoside phosphate in presence of ATP/GTP, TPP and Mg2+. It produces a new strand of DNA. DNA polymerase binds nucleotides in 5'-3' direction.


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In prokaryotes, genetic recombination can occur during

  • transduction

  • transformation

  • conjugation

  • all of these


Extranuclear genes occurs in

  • plastids and are not inherited

  • plasmid and are not inherited

  • mitochondria and are inherited by female

  • mitochondria and are inherited by male


Which of the following pesticides is an acetylcholinesterase inhibitor?

  • Aldrin

  • BHC

  • Endosulfan

  • Malathion


During formation of which of the following free nuclear division occurs?

  • Flower

  • Endosperm

  • Gametes

  • Fruit


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Chloromycetin is obtained from

  • Streptomyces venezuelae

  • Streptomyces rimosus

  • Bacillus subtilis

  • Clostridium botulinum


Which is Indian dwarf wheat?

  • T. dicoccum

  • T. sphaerococcum

  • T. turgidum

  • T. aestivum


The sphere of living matter together with water, air and soil on the surface of earth is called

  • atmosphere

  • hydrosphere

  • lithosphere

  • biosphere


Mutualism is found in

  • hermit crab and sea anemone

  • ox pecker and rhinoceros

  • zoochlorellae and Hydra

  • E.coli and man


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An oocyte is released from the ovary under the influence of LH 

  • after completing meiosis and before polar bodies are released

  • after completing meiosis I and before release of polar bodies

  • after completing meiosis

  • after completing meiosis I and after release of polar bodies.