5) The Limulus amoebocyte assay is used to detect minute amounts of endotoxin in drugs and medical devices.

10) Many pathogens use the same portal for entry and exit from the body

3) The M protein enhances the virulence of Streptococcus by preventing phagocytosis.

4) In A-B exotoxins, the A component binds to the host cell receptor so that the B component can enter the cell.

2) Biofilms provide pathogens with an adhesion mechanism and aid in resistance to antimicrobial agents.

9) Infections with some viruses may induce chromosomal changes that alter the growth properties of host cells.

6) Cytopathic effects, such as inclusion bodies and syncytium formation, are the visible signs of viral infections.

1) In general, the LD50 for exotoxins is much greater than the LD50 for endotoxins.