Match List-I with List-II
| List-I Terms | List-II Explanation |
|---|---|
| (A) Secondary productivity | (I) The amount of biomass or organic matter produced per unit area over a time period by plants |
| (B) Net primary productivity | (II) The rate of formation of new organic matter by consumers |
| (C) Gross primary productivity | (III) The available biomass for the consumption to heterotrophs (herbivores and decomposers) |
| (D) Primary production | (IV) The rate of production of organic matter during photosynthesis |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
(A) Secondary productivity — this matches (II) The rate of formation of new organic matter by consumers. Consumers cannot make food. They build their own bodies from the food they eat, and the rate at which they do so is secondary productivity.
(B) Net primary productivity — this matches (III) The available biomass for the consumption to heterotrophs (herbivores and decomposers). Plants use a part of what they make in their own respiration. What is left (NPP = GPP − R) is the food available to herbivores and decomposers.
(C) Gross primary productivity — this matches (IV) The rate of production of organic matter during photosynthesis. “Gross” means total. GPP is all the organic matter made in photosynthesis, before anything is used up in respiration.
(D) Primary production — this matches (I) The amount of biomass or organic matter produced per unit area over a time period by plants. It is the amount of organic matter that plants make in a given area and time, expressed as weight (g m−2) or energy (kcal m−2).
NCERT Extract:
Productivity – “… Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis. … Gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis. A considerable amount of GPP is utilised by plants in respiration. Gross primary productivity minus respiration losses (R), is the net primary productivity (NPP).
GPP – R = NPP
Net primary productivity is the available biomass for the consumption to heterotrophs (herbiviores and decomposers). Secondary productivity is defined as the rate of formation of new organic matter by consumers.”