A
Most scientists rejected Wegener's theory because he could not explain the force that pushes or pulls the continents.
The saliva has enzymes that start to break down food using the lock and key system.The teeth chews the food and begins mechanical break down of food
Symbiosis...fungi exchange his nutrients and minerals from soil with solar energy from the plant
Speciation can be difficult to observe in nature, but the it is hypothesized that the following occurs in a allopatric speciation's intermediate stage:
(1) closely related species are differentiated through geographic variation (2) then there's reduced fertility in one a geographic race of the species (3) and in the geographic race of subspecies that are to become species.