A farmer harvests his crop and expresses his harvest in three different ways.

$(a)$ I have harvested $10$ quintals of wheat.

$(b)$ I have harvested $10$ quintals of wheat today in one acre of land.

$(c)$ I have harvested $10$ quintals of wheat in one acre of land, 6 months after sowing.

Do the above statements mean one and the same thing. If your answer is yes, give reasons. And if your answer is ‘no’ explain the meaning of each expression.

Which of the following ecosystems will be more productive in terms of primary productivity ? Justify your answer. A young forest, a natural old forest, a shallow polluted lake, alpine meadow.

…………. of an ecosystem is the rate of production of organic matter during photosynthesis.

Plants which are attached to the rocks are called

$A-80\%$ of total global carbon is dissolved in ocean.

$R$- dry weight of organisms have $49\%$ carbon.