Temperature in abyssal zone is
2oC
4oC
1oC
5oC
Trophic level in an ecosystem represents the
water level
energy level
salt level
oxygen
An ecosystem is a natural unit of
ecosphere
biosphere
lonosphere
all the above
Animals permanently living in caves do not have
nose
eyes
legs
stomach
Deserts, mountain peaks, deep layers of sea are examples for
parabiosphere
none of these
Stagnant water is seen in
ponds
lakes
both a and b
Gas used for killing bacteria in water is
nitrogen
carbondioxide
chlorine
helium
Protozoans, rotifers, larvae of insects, crustaceae and moluscs are
phytoplankton
zooplankton
nekton
benthos
Which one of the following is a physical component in a terrestrial ecosystem?
Type of soil
Types of salts in soil
Total salt content of soil
Total content of organic matter in soil
Which of the following pollutants damages the nervous system?
carbon
lead