The amount of carbon dioxide in the atmosphere is regulated mainly by:
1. the atmosphere itself
2. human activities
3. decomposition by microbes
4. the oceanic reservoir

Carbon dioxide is returned to the atmosphere by all the following except:
1. photosynthesis by the primary producers
2. respiratory activities of producers and consumers
3. decomposers
4. volcanic activity

Regarding phosphorus cycle:

1. Only I is true.
2. Only II is true.
3. Both I and II are true.
4. Both I and II are false.

The price tag put by researchers on the annual ecosystem services is about:
1. USD 11 trillion
2. USD 22 trillion
3. USD 33 trillion
4. USD 44 trillion

Identify the incorrectly matched pair:

Identify the incorrectly matched pair:
1. Carnivores -- secondary or tertiary consumer
2. Decomposers -- microbial heterotrophs
3. Herbivores -- primary consumer
4. Omnivores -- molds, yeasts and mushrooms

The process of mineralization by micro-organisms helps in the release of:

Productivity is the rate of production of biomass expressed in terms of :
i. $(\mathrm{kcal}<mspace\; width="1em"></mspace>{\mathrm{m}}^{-3})<mspace\; width="1em"></mspace>{\mathrm{yr}}^{-1}$
ii. $\mathrm{g}<mspace\; width="1em"></mspace>{\mathrm{m}}^{-2}<mspace\; width="1em"></mspace>{\mathrm{yr}}^{-1}$
iii. $\mathrm{g}<mspace\; width="1em"></mspace>{\mathrm{m}}^{-1}<mspace\; width="1em"></mspace>{\mathrm{yr}}^{-1}$
iv. $(\mathrm{kcal}<mspace\; width="1em"></mspace>{\mathrm{m}}^{-2})<mspace\; width="1em"></mspace>{\mathrm{yr}}^{-1}$

Pyramid of numbers is :
1. Always upright
2. Always inverted
3. Either upright or inverted
4. Neither upright nor inverted

Among the following, where do you think the process of decomposition would be the fastest?