Multiple Choice Questions

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Genes which are located only in the X-chromosome are known as

  • epistasis genes

  • holandric genes

  • operator genes

  • antiepistasis genes


A.

epistasis genes

According to Barr body concept (applicable only for X-chromosomes) genes present on the Barr body (inactive X-chromosome) are at times hypostatic due to presence of epistatic genes on the active X-chromosome. Thus, epistasis gene is the most appropriate option. Genes which are located on X-chromosome only are called hologynic genes and those found on Y-chromosome only are called holandric genes.

Epistatis is the phenomenon where the effect of one gene is dependent on the presence of one or modifier genes. Operator gene in Lac operon, is a segment to which a repressor binds.


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The concept of hot- spot was first introduced by

  • Mayer

  • Simpson

  • Myers

  • David


'Kyoto Protocol' is a multination international treaty for

  • phasing out green house gases

  • controlling ozone destroying substances

  • management of hazardous wastes

  • conservation of biodiversity


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  • effect of industrial pollution

  • effect of mutation

  • evidence of survival of fittest

  • evidence of favour of natural selection


Intermediate host of malarial parasite is

  • pig

  • man

  • mosquito

  • larva of mosquito


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  • remains unchanged

  • increases in amount

  • decreases in amount

  • is more available to the aquatic organisms


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  • staminate flower

  • bisexual flower

  • neuter flower

  • pistillate flower


Which codon is not an indicator of completion of protein synthesis?

  • UAG

  • AUG

  • UAA

  • UGA


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  • somaclonal variation

  • micropropagation

  • somatic hybridisation

  • Transgenic technology


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  • rRNA

  • mRNA

  • tRNA

  • snRNA