The functions as a gateway through which chemicals and small particles, such as enter or leave the cell. Substances may move through the membrane by (physical) processes, such as . Substances can also move through the membrane by (physiologicial) processes, such as .

cell membrane

such as water, micro-organism

physical process

simple diffusion, osmosis and filtration

such as potasssium permaganate in water,urea a liver waste diffuses from the body and the kidney help in filtering it out

physiological processs

active transport, phagocytosis and pinocytosis

such as soduim-potassium pump, exocytosis

Explanation:  transportation in and out of cell is done in different ways listed above but a barrier to this movement is the cell membrane which is an outer covering of the cell. it protect the cell and only some materials can penetrate the cell membrane e.g micro-organism, water e.t.c. the various physical and physiological processes are the various ways substance  cna be liquid, solid or gas are transported within or outside the  cell e.g food

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .