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

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

2n-1 condition represent

• tetrasomy

• trisomy

• monosomy

• multisomy

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

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

• Agrobacterium

• E. coli

• T.M.V.

• Bacillus anihracis

DNA polymerase enzyme is required for synthesis of

• DNA from RNA

• RNA from DNA

• DNA from DNA

• RNA from RNA

77.

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

• T₁

• T₂

• T₃

• T₄

The part of earth in which life exist is known as

• Lithosphere

• Biosphere

• Atmosphere

• Hydrosphere

Which type of DNA is found in bacteria

• Helical DNA

• Membrane bound DNA

• Straight DNA

• Circular free DNA

Which is social foresting species

• Leucaena leucocephala

• Tectona grandis

• Mangifera indica

• Rosa indica