Multiple Choice Questions

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Which vertebrate orgen receives only oxygenated blood?

  • Gill

  • Lung

  • Spleen

  • Liver


C.

Spleen

Spleen is the organ that receives only oxygenated blood. Lungs and gills receive both oxygenated and deoxygenated blood. Liver receives deoxygenated blood through hepatic portal system for extracting excess quantities of digested nutrients.


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Photorespiration is favoured by

  • high O2 and low CO2

  • high CO2 and low O2

  • high temperature and low O2

  • high humidity and temperature


The true statement about 'green-house effect' is that it is

  • caused only by CO2

  • caused by CO2, CFCs, CHand NO2 gases

  • caused by combination of many gases

  • none of the above


Cochineal insects have proved very useful for

  • rodents control

  • Parthenium control

  • cactus prevention

  • Eicchornia prevention


'Gymnosperm' have how many species?

  • 1000

  • 900

  • 640

  • 300


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What are the sex organs provided in some bacteria?

  • Circular DNA

  • Gametes

  • Sex pili

  • Plasmid


2,4- D is an effective

  • fungicide

  • weedicide

  • rodenticide

  • wormicide


Which typical stage is known for DNA replication?

  • Metaphase

  • G1- phase

  • S- phase

  • G2- phase


The formation of canal system in sponges is due to

  • reproduction

  • porous walls

  • folding of inner walls

  • gastro- vascular system


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The term 'Meiosis' was given by

  • Johansen

  • Knoll and Ruska

  • A. Flemming

  • Farmer and Moore