<span>The means is unknown. Filoviruses are known for causing hemorrhagic fever in humans. However, once a human is infected, passing the virus from person-to-person is the means by which others become infected. Most especially is the transmission through infected bodily fluids or objects that have been unsterilized and come into contact with those fluids.</span>
Scientific methods must be supported by observations and results from many investigations and are not absolute.
Cell transport is movement of materials across cell membranes. Cell transport includes passive and active transport. Passive transport does not require energy whereas active transport requires energy to proceed. Passive transport proceeds through diffusion, facilitated diffusion and osmosis. The purpose of the transport proteins is to protect the cell's internal environment and to keep its balance of salts, nutrients, and proteins within a range that keeps the cell and the organism alive.