In active transport:
a. molecules move across the plasma membrane by crossing the lipid bilayer directly, rather than by using a transport protein.
b. the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell.
c. no energy input is required from the cell.
d. a vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell.
e. molecules move across the plasma membrane against their concentration gradient.

The correct option is: e. molecules move across the plasma membrane against their concentration gradient

Explanation:

Active transport refers to the movement of the particles or molecules from higher concentration to lower concentration, across the plasma membrane of a cell. This transport requires cellular energy as the movement of the molecules is against the concentration gradient.

Active transport can be divided into primary and secondary active transport.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.