Final answer:
All living cells are surrounded by a cell membrane and contain a cell nucleus. The space between the cell membrane and the nuclear membrane is called the cytoplasm.
Step-by-step explanation:
All living cells are surrounded by a cell membrane. Plant cells and animal cells contain a cell nucleus that is also surrounded by a membrane and holds the genetic information for the cell. Everything between the cell membrane and the nuclear membrane—including intracellular fluids and various subcellular components such as the mitochondria and ribosomes—is called the cytoplasm. The membranes of all cells have a fundamentally similar structure, but membrane function varies tremendously from one organism to another and even from one cell to another within a single organism.