Energy and nutrients enter an ecosystem and hence in a community through:
1. Producers
2. Consumers
3. Detritivores
4. Apex predators

The prime driving force for the water cycle is:

The producers in aquatic ecosystems include all except:

Early seral communities in secondary succession are less productive than in later stages because:

Which of the following is most likely to exhibit the maximum difference between GPP and NPP?
1. phytoplankton in the ocean.
2. corn plants in a farmerʹs field.
3. prairie grasses.
4. an oak tree in a forest.

Primary producers near deep-sea vents are:
1. Chemohetrotrophic prokaryotes
2. Chemoauotrophic prokaryotes
3. Photosynthetic prokaryotes
4. Photosynthetic autotrophs

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

Decomposers like fungi and bacteria are :

Choose the correct answer :

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. $(\mathrm{kcal} {\mathrm{m}}^{-3}) {\mathrm{yr}}^{-1}$
ii. $\mathrm{g} {\mathrm{m}}^{-2} {\mathrm{yr}}^{-1}$
iii. $\mathrm{g} {\mathrm{m}}^{-1} {\mathrm{yr}}^{-1}$
iv. $(\mathrm{kcal} {\mathrm{m}}^{-2}) {\mathrm{yr}}^{-1}$