$A$ man-made ecosystem is:

Match the List-$I$ with List-$II$:

List-$I$	List-$II$
$a$. Carbon dissolved in oceans	$i$. $55$ billion tons
$b$. Annual fixation of carbon through photosynthesis	$ii$. $71 \%$
$c$. $PAR$ captured by plants	$iii$. $4 \times 10^{13} \ kg$
$d$. Productivity of oceans	$iv$. $2$ to $10 \%$

Choose the correct answer from the options given below:

Which of the following is $NOT$ a functional unit of an ecosystem?

Identify the basic components of an ecosystem.

Identify the given food chain:
Grass $\rightarrow$ Grasshopper $\rightarrow$ Birds $\rightarrow$ Lion

Which of the following statements are correct?
$(a)$ Net primary productivity is available biomass for consumption to heterotrophs.
$(b)$ Secondary productivity is defined as the rate of formation of new organic matter by heterotrophs.
$(c)$ The annual net primary productivity of the ocean is greater than that of land.
$(d)$ Warm and moist environment favours decomposition.