Answer:
Primary succession is one type of the ecological succession which takes place on the land devoid of vegetation or barren land.
The species which first flourishes on this barren land are known as pioneer species which includes the species of bryophytes and pteridophytes like lichens and mosses.
These lichens and mosses help breakdown the barren rocks through chemical leaching and help increase the nutrient content. This allows the ferns and small pteridophytes to grow.
Then the area is colonized by the intermediate species which includes herbs, shrubs later trees. These intermediate species help attract the animals and thus help establish the biological community.
Thus, Lichens mosses → herbs→ shrubs →trees.
Streams that flow beneath melting glaciers leave long ridges of layered sediments, known as Esker. Eskers are formed within ice-walled tunnels by streams which flowed within and under glaciers. They tended to form around the time of the glacial maximum when the glacier was slow and sluggish and after the retaining ice walls melted away, stream deposits remained as long winding ridges.
In exothermic reactions, the products have higher energy than the reactants, and in endothermic reactions, the reactants have higher energy than the products.
The answer to the question above is a cell.
