An American plant which had become a troublesome weed in India is
Typha latifolia
Cyperus rotundus
Parthenium
Eichhornia
Correct Answer :
D. Eichhornia
Related Questions
The best indicator of SO^2 pollution is
Lichens
Algae
Fungus
Fems
The biggest herbarium of India is
Botanical Survey of India - Calcutta
St. Xavier's Herbarium - Mumbai
Central National Herbarium - Calcutta
IARI - New Delhi
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
Radiation is a health hazard as it causes
leukaemia
polio
pneumonia
haemophilia
Desert plants are generally
Succulents
Heterophyllous
Herbaceous
Viviparous
First link in any food chain is green plant because
green plants systhesize food
the green plants eat everything
they are fixed at a place
none of these
Vegetation in Delhi is predominantly
halophytic
mesophytic
xerophytic
hydrophytic
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
The ultimate source of energy for fish is
Protozoa
Oxygen produced by plants
Sunlight
Manure in the soil
Hie sequence blue green algae > crustose lichens � foliose lichens > mosses � shrubs � dicotyledonous tree represents
a food chain
genetic drift
ecological succession trend
a phylogenetic trend
One of these is a renewable source of energy:
Solar energy
Hydro-power
Natural gas
All of these
The first stage of plant succession on earth is called
Adaptation
Acclimatisation
Colonisation
All the above
Autumn colouration of leaves appears only in
Tropical regions
Deserts
Temperate deciduous plants
Deserts
Plankton, Nekton and Itenthon are not the components of one of the following ecosystems:
Marine
Freshwater
Grassland
Pond
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
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
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
Which is the correct food chain
grass � wolf > deer > buffalo
bacteria � grass � rabbit > wolf
grass � insect � bird � snake
grass > snake �insect � deer
Pedology is the study of
soil
locomotion of animals
rocks
crop diseases
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
Competition for food, light and space is most severe in
closely related species growing in the same niche
closely related species growing in different habitats
distantly related species growing in same habitat
distantly related species growing in different habitats
In grassland ecosystem the pyramid of energy is
upright
inverted
upright or inverted
none of these
Laterization is a process which results in the
purification of water
formation of soil
sterilization of soil
degradation of soil
Hydrilla is a
suspended hydrophyte
submerged hydrophyte
floating and anchored plant
a free floating hydrophyte
Biosphere is:
In which individuals interact with each other
In which life originated
The name of a bird
Organic compound by which life diminih
Which of the following is normally not at atmospheric pollutant
CO
Hydrocarbons
The least porous soil among the following is
loam soil
clay soil
sandy soil
poeaty soil
When young plants are grazed too heavily they get killed because
the roots are starved
of the mechanical injury to roots
most of the aerial parts are eaten away
of the mechanical injury to branches
What is the major constituent of biomass of an organism
Nitrogen
Carbon
Phospnorus
Oxygen
The nitrifying bacteria which oxidise nitrite to nitrates include
Nitrosomonas
Azotobacter
Nitrobacter
Closteridium