Productivity is the rate of production of biomass expressed in

$\left(\mathrm{i}\right) \left(\mathrm{kcal} {\mathrm{m}}^{-3}\right) {\mathrm{yr}}^{-1} \left(\mathrm{ii}\right) {\mathrm{gm}}^{-2} {\mathrm{yr}}^{-\mathrm{1 \; \; \; \; \; \; }}$
$\left(\mathrm{iii}\right) {\mathrm{g}}^{-1} {\mathrm{yr}}^{-1} \left(\mathrm{iv}\right) \left(\mathrm{kcal} {\mathrm{m}}^{-2}\right) {\mathrm{yr}}^{-1}$

1. (ii)

2. (iii)

3. (ii) and (iv)

4. (i) and (iii)

Which of the following ecosystems is most productive in terms of net primary production?

1. Deserts

2. Tropical rain forests

3. Oceans

4. Estuaries

How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?

1. 1%

2. 10%

3. 40%

4. 90%