Reference no: EM132644410

1) An organism that benefits by living in or on, another organism to which it causes no harm or benefit is known as:

A. parasite

B. saprophyte

C. commensal

D. pest

2) Antibodies are released by:

A. B cells

B. macrophages

C. neutrophils

D. T cells

3) The body has two ways of protecting itself from invading pathogens once they have entered- antibody mediated immunity and cell-mediated immunity.

i) Name one group of microorganisms against which - 1) antibody mediated immunity is most effective. 2) cell mediated immunity is most effective

ii) In each case name the cell that is activated first in response to a pathogen to which the body is constantly exposed and state the response of each cell type to the pathogen.

4). Describe the ways in which healthy human skin and the organ systems that open into the external environment protects the body against invading pathogens.