Electron Microscopy - an imaging method, which uses a focused beam of electrons to enlarge the image of an object on a screen or photographic plate.

Endocytosis - the process in which cells take in fluids or other large molecules.

Enzyme - a type of protein, which catalyzes the reactions between substrates (substances).

Filovirus - The thread-like virus family which includes such viruses as Ebola and Marburg; very deadly.

Genes - a sequence of DNA or RNA that is located on a chromosome and that is the functional unit of inheritance controlling the transmission of traits and function of other genetic material.

Glycoprotein - a compound produced by mixing a protein with any member of a carbohydrate group.

Helper T cells - coordinate the actual immune response of the body; they let other T cells and B cells do their jobs.

Hemorrhagic fever - a condition characterized by non-stop internal or external bleeding resulting from a viral infection which has caused blood vessel damage.

Hereditary material - material responsible for the transmission of qualities from ancestor to descendant through genes.

Host - a living organism, which provides subsistence or lodgment to a parasite.

Humoral immune response - the immune responses mediated by antibodies.

Inactivated vaccine - dead microorganisms used as antigens to produce immunity.

Inclusion bodies - strange and unusual structures found inside a host cell during virus replication.

Infection - the state produced by the presence of an infective agent in or on a suitable host.

Immune System - A body function designed to defend the body from disease causing microorganisms.

Immunity - the condition of being immune, the protection against infectious disease.

Latent infection - viral infection in which the virus responsible is able to avoid the hosts immune system and defenses.

Leukocytes - the majority of the specialized cells used in the immune system; white blood cells.

Lipid - a fatty and oily compound used by cells as energy reserves and material for structure.

Lymph nodes - small bean-shaped organ made up large numbers of lymphocytes, macrophages and accessory cells located along the lymphatic system.

Lymphoid tissue - tissue made up white blood cells and special fibers.

Lysis - the cell membrane of a host is completely destroyed and newly replicated viruses are unleashed instantaneously.