In a food chain, the largest population is that of
decomposers
producers
primary consumers
tertiary consumers
The transfer of energy from one tropic level to another is governed by the 2nd law of thermodynamics. The average efficiency of energy transfer from herbivores to carnivores is
5%
10%
25%
50%
The nature of climax community ultimately depends on
climate
bed rock
soil organisms
pool of available nutrients
Niche of a species in an ecosystem refers to its
function at its place of occurrence
place of its occurrence
competitive ability
centre of origin
In increasing order of organizational complexity, which one of the following is the correct sequence?
Population, species, community, ecosystem
Population, variety, species, ecosystem
Population, ecosystem, species, community
Species, variety, ecosystem, community
Keystone species in an ecosystem are those
present in maximum number
that are most frequent
attaining a large biomass
contributing to ecosystem properties
Which of the following ecosystems has highest rate of gross primary production?
Grasslands
Mangroves
Coral reefs
Equatorial rain forest
During adverse season, therophytes survive by
Bulbs
Corms
Rhizomes
Seeds
What is the most important factor for the success of animal population?
Natality
Unlimited food
Adaptability
Inter-species activity
MAB stands for
Man and Biology Programme
Man and Biosphere Programme
Mammals and Biosphere Programme
Mammals and Biology Programme
Plants such as Prosopis, Acacia and Capparis represents examples of tropical
thorn forests
deciduous forests
evergreen forests
grasslands
An interesting modification of flower shape for insect pollination occurs in some orchids, in which a male insect mistakes the pattern on the orchid flower for the female of his species and tries to copulate with it, thereby pollinating the flower. This phenomenon is called
Mimicry
Pseudopollination
Pseudocopulation
Pseudoparthenocarpy
A sewage treatment process, in which a portion of the decomposer bacteria present in the waste is recycled into the beginning of the process, is called
Primary treatment
Activated sludge treatment
Tertiary treatment
Cyclic treatment
Two opposite forces operate in the growth and development of every population. One of them re-lates to the ability to reproduce at a given rate. The force opposing to it is called
Mortality
Fecundity
Biotic control
Environmental resistance
The rate at which light energy is converted to the chemical energy of inorganic molecules is the ecosystem’s
Net primary productivity
Gross primary productivity
Net secondary productivity
Gross secondary productivity
Sudden mass kill of fishes is likely in
Mesotrophic lake
Oligotrophic lake
Salt lake
Eutrophic lake
Which part of the world has a high density of organisms?
Grasslands
Savannahs
Deciduous forests
Tropical rain forests
Energy transfer from one trophic level to other, in a food chain, is
1%
2%
10%
20%
Pneumataphores are characteristic of plants growing in
Saline soils
Sandy soils
Marshy places and salt lakes
Dryland regions
The greatest biomass of autotrophs in the oceans is that of
sea grasses and slime moulds
free floating microalgae, cyanobactyeria and nanoplankton
benthic brown algae, coastal red algae and daphnids
benthic diatoms and marine viruses