Since all cells of the shoot system originate through cell divisions occurring in the shoot apical meristem, how do the different cell types of the shoot system come about?

Acell in the human nervous system whose primary function is to form myelin and the blood-brain barrier, respond to injury, remove debris, and enhance learning and memory is called a(n) cell.

How does secondary succession differ from primary succession?

In general, are there any major differences that you can see? explain