A fertile agriculture soil appears dark coloured at the surface as compared to soil one metre down.The reason for colour of top soil is
More moisture
Rich in organic matter
Rich in iron,calcium and magnesium
Recent formation
Tropical forests occur in India.
Jammu and Kashmir
Rajasthan
Kerala and Assam
The forests do not occur in India
Atmosphere of big /metropolitan cities is polluted most by
Automobile exhausts
Pesticide residue
Household waste
Radioactive fall-out
Second most important tropic level in a lake is
Zoo plankton
Phytoplankton
Bent hos
Neuston
Which important green-house gas, other than methane, is being produced from the agricultural fields?
Arsine
Sulphur dioxide
Ammonoa
Nitrous oxide
Sunken stomata is the characteristic feature of
Hydrophyte
Mesophyte
Xerophyte
Halophyte
Pyramid of numbers in a grassland / true ecosystem is
Always inverted
Always upright
Both (a ) and ( b )
Spindle-shaped
Homeostasis is
Tendency of biological system to change with change in environment
Tendency of biological systems to resist change
Disturbance of self regulatory system and natural controls
Biotic materials used in homeopathic medicine
The most common indicator organism which represents polluted water is:
Escherichia coli
Salmonella typhi
Vibrio cholerae
Entamoeba histolytica
The primary succession refers to the development of communities on a
Freshly cleared crop field.
Forest clearing after devastating fire.
pond , freshly filled with water after a dry phase.
Newly-exposed habitat with no record of earlier vegitation.
