The primary function of molecular membranes is the transport of ions and molecules in and out of cells. The movement of molecules from areas of low concentration to those of high concentration against chemical gradients is best described as:

a. active transport.
b. transcytosis.
c. inactivated transport.
d. passive transport.
e. channel mediated diffusion.

the sphincter muscles at the end of the digestive tract is the anus.

they have identical fossils of organisms that have evolved over time.

both have animal fossils preserved in them due to weathering and erosion.

they contain different fossils because life on earth has changed through time.

the fossils in them were formed on the surface of earth due to exposure to sunlight.

not sure what it is