Active transport. it's the only method of transfer of material that is again concentration gradient
Growth is always the primary result of cell division
They survived by moving to new areas.
The primary succession takes a long time to be done. the secondary succesion takes 200-500 years for completion. the secondary succession occurs in an area which has been denuded recently and lately inhabited. soil is present at the beginning of the secondary succession with some organisms. thank you for this question.