Multiple Choice Questions

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Double fertilization means

  • fusion of nucleus of male gamete with the egg nucleus

  • fusion of two polar nuclei

  • fusion of sperm nucleus with secondary nucleus

  • fusion of one sperm nucleus with nucleus and fusion of other sperm nucleus with secondary nucleus


D.

fusion of one sperm nucleus with nucleus and fusion of other sperm nucleus with secondary nucleus

Double fertilization was first observed by Nawaschin (1892) in Lilium and Fritillaria and confirmed by Grignard. It is characteristic of angiosperms. In double fertilization first fertilization is normal and second, as it involves three nuclei is known as triple fusion.


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DNA polymerase enzyme is required for synthesis of

  • DNA from RNA

  • RNA from DNA

  • DNA from DNA

  • RNA from RNA


Which is social foresting species

  • Leucaena leucocephala

  • Tectona grandis

  • Mangifera indica

  • Rosa indica


In terrestrial ecosystem such as forest, maximum energy is found in which trophic level

  • T1

  • T2

  • T3

  • T4


2n-1 condition represent

  • tetrasomy

  • trisomy

  • monosomy

  • multisomy


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Which type of DNA is found in bacteria

  • Helical DNA

  • Membrane bound DNA

  • Straight DNA

  • Circular free DNA


The part of earth in which life exist is known as

  • Lithosphere

  • Biosphere

  • Atmosphere

  • Hydrosphere


Micro-organism which act as a vehicle for foreign gene transfer in higher plants

  • Agrobacterium

  • E. coli

  • T.M.V.

  • Bacillus anihracis


Restriction enzymes are used in genetic engineering, because they

  • can degrade harmful proteins

  • can join different DNA fragments

  • can cut DNA at specific base sequence

  • are nucleases that cut DNA at variable sites


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Which of the following statement is correct about DDT

  • It is a biomagnifying biodegradable pollutant

  • It is non biomagnifying biodegradable pollutant

  • It is biomagnifying non biodegradable pollutant

  • It is not a pollutant