Class 12th Biology 2017 Set1 Outside Delhi Board Paper Solution
What is an ecological pyramid ? Compare the pyramids of energy, biomass and numbers.
Ecological pyramid : The relation between producers and consumers in an ecosystem can be graphically represented in the form of a pyramid called ecological pyramid. Ecological pyramids are of 3 types :
(i) Pyramid of number
(ii) Pyramid of biomass
(iii) Pyramid of energy
(i) Pyramid of number : The relationship between producers and consumers in an ecosystem can be represented in the form of a pyramid in terms of number is called pyramid of number. For most ecosystem like grassland, pyramids of numbers are upright because numbering of organisms decreases at successively higher trophic level.
(ii) Pyramid of Biomass : The relationship between producers and consumers in an ecosystem can be represented in the form of a pyramid in terms of biomass is called pyramid of biomass. It can be upright or inverted. It represent the total dry weight of living beings of different species at each trophic level at a perticular time.
(iii) Pyramid of energy : The relationship between producers and consumers in an ecosystem can be represented in the found of pyramid in terms of flow of energy called pyramid of energy. Always upright as energy is lost as heat at each step. It reflects more accurately the law of thermodynamics, with loss of energy being depicted at each transfer to another trophic level, hence the pyramid is alwasys right.
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