In photosynthesis, which substances are used up, which are produced and which are necessary, but remain unchanged after the reaction?

The general requirement for energy and materials is common to all living organisms. Living beings need plants and trees in order to survive, as most of their needs are met by them.

Read the passage and answer the questions.

(i) Do plants also depend on some source for food production? Explain.

(ii) How do we derive nutrition for survival? How does this nutrition vary among different organisms?

(iii) What do we learn concerning the increased cutting of trees and removal of the green cover?

Reading about the digestive glands and their action, a student got confused about some facts. Given below are some questions, concerning the facts.

(i) Why cannot we digest raw green plants in our alimentary canal?

(ii) Why are digestive enzymes present in an inactive form in the body when we can require their action any time?

(iii) HCL is an acid which kills bacteria ingested with food, but does not harm the walls of stomach. Why?

(iv) What values do you think the student conveys from his questions?

The diagram shows the arrangement of cells inside the leaf of a green plant. (No cell contents are shown).

Which cells normally contain chloroplasts?

Choose the forms in which most plants absorb nitrogen:

I. Proteins

II. Nitrates and nitrites

III. Urea

IV. Atmospheric nitrogen

Choose the correct option.