During a study tour teacher showed the primary colonisers on the banks of the river 'Nila'.
a. Identify the succession and justify your answer.
b. List the different stages of the identified succession.

The graph shows the variation of photoelectric current with accelerating potential of different intensities. a. What conclusion do you arrive from the graph? b. Photoelectric current is not zero even if the accelerating voltage is zero. Justify your answer. c. Why two curves meet at one point on the retarding potential axis ?

The given flowchart shows the fate of carbohydrates during digestion in the human alimentary canal. Identify the enzymes acting at stages indicated as A, B, C and D and select the correct option.