Make an outline sketch of nitrogen cycle.

Describe nitrogen cycle.

Refer to the given outline of nitrogen cycle. Identify X and Y and select the correct statement regarding them.

(i) Make a neat and labelled sketch of nitrogen cycle in nature. (ii) Describe in brief the role of nitrogen fixing bacteria and of lightenng in fixing atmospheric nitrogen. OR (i) Draw a neat labelled sketch of carbon cycle in nature. (ii) What is green house effect? How does carbon dioxide cause global warming in the atmosphere.

Draw an outline to show the carbon cycle in nature .

Draw a diagrammatic sketch of oxygen cycle in nature?

Draw diagrammatic sketch of oxygen cycle in nature.