The annual net primary productivity of the whole biosphere is approximately

Which one of the following is the most productive ecosystem?

Arrange the following ecosystems in increasing order of their mean NPP (tons/ha/year).
$\left(\mathrm{a}\right)$ Tropical deciduous forest
$\left(\mathrm{b}\right)$ Temperate coniferous forest
$\left(\mathrm{c}\right)$ Tropical rainforest
$\left(\mathrm{d}\right)$ Temperate deciduous forest

Fragmentation, leaching, and catabolism are some important steps of decomposition. Study the following statements [(i), (ii), and (iii)] regarding these and select the correct option.
(i) Detritivores (e.g., earthworm) breakdown detritus into smaller particles.
(ii) Water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.
(iii) Decomposers (e.g., bacteria and fungi) secrete digestive enzymes and degrade detritus into simpler inorganic substances.

	Leaching	Fragmentation	Catabolism
$\left(\mathrm{a}\right)$	(i)	(ii)	(iii)
$\left(\mathrm{b}\right)$	(iii)	(ii)	(i)
$\left(\mathrm{c}\right)$	(ii)	(i)	(iii)
$\left(\mathrm{d}\right)$	(ii)	(iii)	(i)

Read the given statements and select the correct option.
Statement 1: Decomposition is the physical and chemical breakdown of complex organic matter into simple inorganic substances.
Statement 2: Humification is the process of formation of humus from detritus or organic remains.

Which of the following is not a characteristic of humus?

Match Column I with Column II and select the correct option from the given codes.

	Column I		Column II
$\left(\mathrm{a}\right)$	Gross primary productivity	$\left(\mathrm{i}\right)$	Self-sustainable ecosystem
$\left(\mathrm{b}\right)$	Net primary productivity	$\left(\mathrm{i}\mathrm{i}\right)$	Aquatic ecosystem
$\left(\mathrm{c}\right)$	Pond	$\left(\mathrm{i}\mathrm{i}\mathrm{i}\right)$	O2 requiring process
$\left(\mathrm{d}\right)$	Aquarium	$\left(\mathrm{i}\mathrm{v}\right)$	Photosynthetic production
$\left(\mathrm{e}\right)$	Decomposition	$\left(\mathrm{v}\right)$	Available to secondary consumers

During the process of decomposition