The most vital process for the existence of life on Earth is

Which of the following proteins is the most abundant on Earth?

Why are green plants necessary for living organisms?

$I.$ In $C_{3}$-plants,the Calvin pathway takes place in mesophyll cells.
$II.$ In $C_{4}$-plants,the Calvin pathway takes place in the mesophyll cells.
Which of the following statements is true?

$A-$ In stroma,enzymatic reactions synthesize sugar which in turn forms starch.
$R-$ The membrane system of chloroplast is responsible for trapping the light energy and also for the synthesis of $ATP$ and $NADPH$.

Which of the following methods is responsible for $ATP$ production by green plant cells in the presence of sunlight?