Match List-I with List-II

Choose the correct answer from the options given below:

(A)-(III), (B)-(I), (C)-(IV), (D)-(II)

The correct answer is Option (1) → (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

A. Humification leads to accumulation of a dark coloured amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. Being colloidal in nature it serves as a reservoir of nutrients.

B. Except for the deep sea hydro-thermal ecosystem, sun is the only source of energy for all ecosystems on Earth. Of the incident solar radiation less than 50 per cent of it is photosynthetically active radiation (PAR). Plants and photosynthetic bacteria (autotrophs), fix Sun’s radiant energy to make food from simple inorganic materials. Plants capture only 2-10 per cent of the PAR and this small amount of energy sustains the entire living world.

C. A trophic level is the nutrition-based, specific position an organism occupies in a food chain, depending on what it eats and how it obtains energy.A trophic level is the position an organism occupies in a food chain, based on what it eats and who eats it.

D. Each trophic level within an ecosystem has a specific amount of living material present at a given point in time, which is referred to as the "standing crop." This standing crop can be quantified by measuring either the biomass (mass of living organisms) or the population number of organisms within a defined unit area.