Q.

Look at the passage given below carefully and answer the following questions from (i) to (v).

Photosynthesis is the process used by plants, algae and certain bacteria to turn sunlight, carbon dioxide left parenthesis C O  right parenthesis and water into food (sugars) and oxygen. There are two types of photosynthetic processes: oxygenic photosynthesis and anoxygenic photosynthesis. They both follow very similar principles, but oxygenic photosynthesis is the most common and is seen in plants, algae and cyanobacteria.

 

(iii) An appropriate entry for the box 3 shown in the figure is:

1 oxygen  
2 air  
3 carbon dioxide  
4 nitrogen  

Ans.

(3)