Two species of antelope ground squirrels are separated by the grand canyon. they are hypothesized to descend from a common ancestor, populations of which were separated as the canyon formed. if this hypothesis is correct, it would be an example of: sympatric speciation by vicariance. sympatric speciation by dispersal. peripatric speciation by vicariance. allopatric speciation by vicariance. allopatric speciation by dispersal.

When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? view available hint(s)when in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? active transportexocytosis