Answer;
C. A wall of stones and mortar
This would act as a model describing the cell membrane.
Explanation;
A cell membrane is made up of a phospholipid bilayer with embedded proteins.
A cell membrane hold the different components of the cell together and to protect it from the environment outside the cell. It acts as a boundary between the inside environment and the outside environment of a cell.
It regulates the materials that enters and exits the cell; through selective movement of substances in and out of the cell.
1) is right option. The fossils are an extinct specie of elephants, and they're related to present day elephants.
Answer:yes
Explanation:
Ion pumps are assemblies of integral membrane proteins, like ion channels, that modulate ion transport into and out of a cell or organelle, leading to generation of electrical signals. Ion pumps, however, work against their concentration gradient, so require energy input, but the energy can also be derived from the concentration gradient of another ion.
