(a) Given below is a pyramid of biomass in an ecosystem where each bar represents the standing crop available in the trophic level. With the help of an example explain the conditions where this kind of pyramid is possible in nature?

(b) Will the pyramid of energy be also of the same shape in this situation? Give reason for your response.

With suitable examples explain the energy flow through different trophic levels. What does each bar in this pyramid represent ?

Draw a 'pyramid of numbers' of a situation where a large population of insects feed upon a very big tree. The insects in turn, are eaten by small birds which in turn are fed upon by big birds. (b) Differentiate giving reason, between the pyramid of biomass of the above situation and the pyramid of numbers that you have drawn.

Which of the following statement/s regarding ecological pyramid is/are wrong? I. In most ecosystem, all the pyramids, of number, of energy and biomass are upright. II. Each trophic level has a certain mass of living material at a particular time called as the standing crop. III. The pyramid of biomass in sea is generally upright because the biomass of fishes far lower that of phytoplankton. IV. Pyramid of energy is always upright, can never be inverted. V. Energy at a lower trophic level is always less than at a higher level.

(A) The amount of living matter (biomass) present at every trophical level is called standing crop (B) Saprophytes are not given any place in ecological pyramids (C ) Ecological pyramid does not account for the same species belonging to two or more trophic levels

Study the following statements and the incorrect ones. (i) Pyramids of energy and yearly biomass production can never be inverted, since this would violate the laws of thermodynamics. (ii) Pyramids of standing crop and numbers can be inverted, since the number of organisms at a time does not indicate the amount of energy flowing throgh the system. (iii) There are certain limitations of ecological pyramids such as they do not take into account the same species belonging to two or more trophic levels. (iv) Saprohytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.