Humus is an example of
soil structure
organic colloids
crystalloids
none of the above
Correct Answer :
B. organic colloids
Related Questions
An area of soil is thoroughly wetted and allowed to drain until capillary movement of water is stopped. The water content of the soil now gives
storage water
capillary water
field capacity
gravitational water
Laterization is a process which results in the
purification of water
formation of soil
sterilization of soil
degradation of soil
Mark which is true
A food chain is a chain of food consumers
A food chain is chain of food producers
A food chain is a series of organisms through which food energy flows in an ecosystem
None of the above
Primary treatment of sewage means
encouragement of growth of microbes to decompose sewage
disinfection of sewage
removal of heavy grit from sewage in the settling chambers
pumping of sewage into aeration tanks for increased microbial activity
What will happen if our water resources are continued to be polluted by industrial wastes
Sufficient food will not be available to water organisms
Sufficient oxygen will not be available to water organisms
Drinking water will not be available
B.O.D value of water will decrease
An American plant which had become a troublesome weed in India is
Typha latifolia
Cyperus rotundus
Parthenium
Eichhornia
The food chain in which microorganisms break down the energy-rich compounds synthesized by producers is
parasitic food chain
consumer food chain
detritus food chain
predator food chain
Vegetation in Delhi is predominantly
halophytic
mesophytic
xerophytic
hydrophytic
Pedology is the study of
soil
locomotion of animals
rocks
crop diseases
In grassland ecosystem the pyramid of energy is
upright
inverted
upright or inverted
none of these
The biggest herbarium of India is
Botanical Survey of India - Calcutta
St. Xavier's Herbarium - Mumbai
Central National Herbarium - Calcutta
IARI - New Delhi
A habitat of long severe winters and growing season limited to a few months of summer constitutes
Taiga ecosystem
Tundra ecosystem
Savannah ecosystem
Tropical rainforest
Which of the following is normally not at atmospheric pollutant
CO
Hydrocarbons
Correct definition of ecosystem is :
A community of organisms interacting with one another
The abiotic component of a habitat
The part of the earth and its atmosphere which inhabits living organisms
The community of organisms together with environment in which they live
Silent valley is situated in
Kashmir
Kerala
Africa
America
Radiation is a health hazard as it causes
leukaemia
polio
pneumonia
haemophilia
The least porous soil among the following is
loam soil
clay soil
sandy soil
poeaty soil
The source of energy in the ecosystem is:
decomposition of animals and plants by bacteria
photosynthesis by green plants
fermentation of sugars
sun-light
. Biome is
the flora on land
the flora in ocean
a community of organisms interacting with each other
that part of earth and its atmosphere which inhabits living organisms
Autumn colouration of leaves appears only in
Tropical regions
Deserts
Temperate deciduous plants
Deserts
Smog is a common pollutant in places having
excessive so2 in their air
excessive ammonia in the air
low temperature
high temperature
Hie earliest settlers on barren lands are generally
Diatoms
Lichens
Mosses
Ferns
Commensalism is
when both organisms are benefited
when one organism is benefited without affecting the other
when one organism is affected
when both organisms are affected
Which is the correct food chain
grass � wolf > deer > buffalo
bacteria � grass � rabbit > wolf
grass � insect � bird � snake
grass > snake �insect � deer
Increasing accumulation of DDT in organisms of a food chain in higher trophic levels is known as
biotic potential
biotic component
biological value
biological amplification
A pollutant is any substance, chemical or other factor that changes
natural geochemical cycles
the natural flora of a place
the natural wild life of a region
the natural balance of our environment
Desert plants are generally
Succulents
Heterophyllous
Herbaceous
Viviparous
What is the major constituent of biomass of an organism
Nitrogen
Carbon
Phospnorus
Oxygen
The first stage of plant succession on earth is called
Adaptation
Acclimatisation
Colonisation
All the above
In cities like Mumbai and Delhi, the major air pollutants are
ozone
carbon monoxide and oxides of sulphur
hydrocarbons and hot air
algae spores and marsh gas