Match List - I with List -II.

List - I		List - II
(A)	Detritus food chain	(I)	Available biomass for consumption
(B)	Standing state	(II)	Dead organic matter
(C)	Standing crop	(III)	Amount of nutrients in soil
(D)	Net Primary Productivity	(IV)	Mass of living material

Choose the correct answer from the options given below:

Key Points

• Detritus food chain - 
  • It begin with dead organic matter and go from non-living organic matter to detritivores and their predators.
  • Example - Dead leaves → Woodlouse → Blackbird
• Standing state - 
  • The amount of nutrients present in the soil at any given time in known as the standing state.
  • The nutrients include carbon, nitrogen, phosphorus, calcium, etc.
• Standing crop - 
  • Standing crop refers to the mass of living material at each trophic level at a particular time.
  • It is measured as the biomass or number of organisms in that area.
• Net Primary Productivity (NPP) - 
  • It is the amount of biomass available for the consumption of heterotrophs i.e., organic matter in excess of the respiratory utilization by the plants.
  • It can be expressed as: NPP = GPP - R, where GPP is Gross primary productivity and R denotes Respiratory losses.

Corrected Table:

Hence, the correct answer is option 4.