In plants,food is stored as ........ .

$I.$ 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?

For photosynthesis (i.e.,for synthesis of organic matter),the green plants need:

The statement "We are created by chloroplast" suggests the idea that:

Which would do maximum harm to a tree?

Which of the following is $NOT$ a utility of photosynthesis?