Differentiate a physical barrier from a mechanical removal mechanism and give an example of each.

Of seawater increases with decrease in the temperature. therefore, the cold water sinks to the deeper layers at the bottom

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

Which direction does the energy flow in this energy pyramid ?