Productivity contributed by oceans is . . . . . . but area covered is comparatively . . . . . . .

Which of the following ecosystems has the highest productivity?

$A$: In secondary productivity,no new organic matter is formed.
$R$: It is only the utilisation of part of food manufactured by primary producers in the building of consumer biomass.

Gross Primary Productivity $(GPP)$ is defined as:

State whether the following statements are True or False:
$I.$ The total organic matter synthesized by the producers in the process of photosynthesis per unit time and area is known as gross primary productivity.
$II.$ Net primary productivity is the weight of the organic matter stored by the producers in a unit area/volume per unit time.

Which ecosystem has the highest gross primary productivity?