Answer the following statements true (T) or false (F)
1. The exoenzyme that causes toxic shock syndrome is called erythrogenic toxin.
2. The neurotoxins produced by Clostridium botulinum and Clostridium tetani cause a spastic, rigid type of paralysis.
3. Although most people use the terms “infection” and “infectious disease” synonymously, microbiologists define infection as colonization by a pathogen.
4. Avirulent strains do not cause disease.
5. It is thought that the waxes in the cell walls of Mycobacterium tuberculosis protect this pathogen from digestion within phagocytes.
1. FALSE
2. FALSE
3. TRUE
4. TRUE
5. TRUE
You might also like to view...
Describe the following concepts to microscopy.
a. magnification: b. resolving power: c. contrast:
Which of the following statements is true concerning dark-field microscopy?
a. This type of microscopy uses specific stains to enhance the contrast of certain bacteria. b. The condenser does not allow light to pass directly through the specimen but directs the light to hit the specimen at an oblique angle. c. Dark-field microscopy allows the visuali-zation of larger viruses. d. Dark-field microscopy can differentiate various difficult-to-grow organisms by using immunofluorescence.
Some, but not all, virus capsids are surrounded by
A. either DNA or RNA. B. a protein spore coat. C. both DNA and RNA. D. a protein capsid. E. a membranous envelope.
Some flowers have distinctive patterns that only reflect ultraviolet light and therefore are invisible to humans. Which statement about such markings is not correct?
A. Flowers with ultraviolet patterns usually appear yellow or orange to humans. B. Carotenoid pigments are responsible for the ultraviolet patterns. C. The ultraviolet patterns are highly visible and attractive to bees. D. The ultraviolet patterns repel birds and bats from the flowers. E. The ultraviolet patterns often form a conspicuous central bull's eye or identify the best landing sites.