Class 12th Biology 2016 Set1 Outside Delhi Board Paper Solution

Question 22

Differentiate between primary and secondary succession. Provide one example of each.

Answer

Primary succession :

1) The invading species are either lichens (on rocks) or phyto planktons (in water).

2) Rate of succession is slow

3) Climax is slow to reach

Example: Newly cooled lava / bare rocks / newly created ponds or reservoir

Secondary succession:

1) The invading species depend on the condition of soil,availablility of water and type of seed.

2) Rate of succession is faster

3) Climax is reached faster.

Example: Abandoned farm lands / burnt or cut forests / lands that have been flooded