What is BOD?
Amount of O2 utilised by organisms in water
Amount of O2 utilised by microorganisms for biological oxidation
Total amount of O2 present in water
All the above
In a population unrestricted reproductive capacity is called as
biotic potential
fertility
carrying capacity
birth rate
Bamboo plant is growing in a fir forest then what will be the trophic level of it?
First trophic level (T1 )
Second trophic level (T2 )
Third trophic level (T3 )
Fourth trophic level (T4 )
Diffuse porous woods are characteristic of plants growing in
tropics
alpine region
cold winter regions
temperate climate
What is a keystone species?
A species which make up only a small proportion of the total biomass of a community, yet has a huge impact on the community’s organization and survival
A common species that has plenty of biomass, yet has a fairly low impact on the community’s organization
A rare species that has minimal impact on the biomass and on other species in the community
A dominant species that constitutes a large proportion of the biomass and which affects many other species.
Which of the following is expected to have the highest value (gm/m2 /yr) in a grassland ecosystem?
Secondary production
Tertiary production
Gross production (GP)
Net production (NP)
If by radiation all nitrogenase enzymes are inactivated, then there will be no
fixation of nitrogen in legumes
fixation of atmospheric nitrogen
conversion from nitrate to nitrite in legumes
conversion from ammonium to nitrate in soil
An ecosystem which can be easily damaged but recover after some time if damaging effect stops will be having
Low stability and high resilience
High stability and low resilience
Low stability and low resilience
High stability and high resilience
In which one of the following habitats does the diurnal temperature of soil surface vary most?
Shrub land
Forest
Desert
Grassland
Barophilic prokaryotes:
grow and multiply in very deep marine sediments
occur in water containing high concentrations of barium hydroxide
readily grow and divide in sea water enriched in any soluble salt of barium hydroxide
grow slowly in highly alkaline frozen lakes at high altitudes
Which one of the following pairs is mismatched?
Tundra -permafrost
Savanna -acacia trees
Prairie -epiphytes
Coniferous forest -evergreen trees
Which one of the following is not used for construction of ecological pyramids?
Number of individuals
Rate of energy flow
Fresh weight
Dry weight
Niche overlap indicates______
two different parasites on the same host
sharing of one or more resources between the two species
mutualism between two species
active cooperation between two species