Multiple Choice QuestionsAs insecticides reach at higher trophic level in food chain their concentration :
increases
become irregular
remain constant
decreases
The food chain starts from :
consumer
producer
decomposer
nitrogen fixation
B.
producer
Food chain initiates from producers. Transfer of food energy from producers takes place through a series of organisms, i.e herbivores to carnivores to decomposers with repeated eating and being eaten is known as food chain.
Producers utilise the radient energy of sun which is transformed to chemical energy during photosynthesis. Thus, green plants occupy first trophic level in any food chain.
Some students, during a study, caught, marked and released 80 fishes in a pond. Later 100 fishes were caught at random. Among these 40 were found to be marked. What is the approximate number of fishes in the pond?
50
100
200
4000
The breakdown of detritus into small particles by detritivores is called
Leaching
Humification
Catabolism
Mineralization
Mineralization
Which of the following statements about Productivity is true?
Primary productivity of all ecosystems is a constant
The annual net primary productivity of the whole of the biosphere is 17 billion tons (dry weight) of organic matter
Net primary productivity is the amount of biomass available for consumption by carnivores
Secondary productivity is defined as the rate of formation of new organic matter by decomposers .
Secondary productivity is defined as the rate of formation of new organic matter by decomposers .
The pioneer species in Xerarch and Hydrarch succession are respectively
Lichens and sedges
Lichens and rooted hydrophytes
Phytoplanktons and lichens
Lichens and phytoplanktons
Lichens and phytoplanktons
According to Robert Constanza, 50% of the total cost for ecosystem services goes to
Recreation
Soil formation
Nutrient cycling
Climate regulation
Climate regulation
Switch
