Why is it a good idea to immunize little boys against rubella?
A. As this is a sexually-transmitted disease, vaccinating girls AND boys early in their lives prevents the spread of the disease in adulthood.
B. We want to achieve herd immunity, and there's no reason why only girls would be infected by this virus. By vaccinating the entire population, we achieve a higher degree of herd immunity than is possible by vaccinating only girls.
C. Only boys get this disease, and one of the common complications is sterility.
D. While this disease is quite strikingly symptomatic in girls, it is completely asymptomatic in boys. Boys can be carriers and transmit it easily to girls they are in close proximity to without realizing it through respiratory secretions. This can lead to large-scale and dangerous outbreaks in the female population.
Which of the following is/are obligate intracellular parasites?
A. Chlamydia and Rickettsia
B. E. coli and Pseudomonas
C. Mycoplasma
D. Treponema pallidum
Reticulate and elementary bodies are two forms of
A. Mycoplasma.
B. Caulobacter.
C. Chlamydia.
D. Myxobacteria.
Who would have larger numbers of bacteria living on the surface of their skin, a person living in the tropics or in the desert, and why?
A. The tropics would provide more shade, so the surface of the skin wouldn't be exposed to high levels of ultraviolet radiation. This would protect the bacteria on the skin, and they would have higher numbers due to this shading effect.
B. The very low humidity of the desert would lead to rapid evaporation of sweat and sebum from an individual's skin. Bacteria need these secretions for a nutrient source. Without them, bacteria would be found in much lower numbers on the skin of a person in the desert than the skin of the person in the tropics.
C. The constant secretion (and lack of evaporation) of high amounts of sweat would produce a highly salty environment on the skin of a person in the tropics. This would provide a local environment that would be too hostile for microbes to survive, so the number of microbes on the skin of the person in the tropics would be lower than that of the person in the desert.
D. The constant secretion of large amounts of sweat would wash bacteria off of the skin of the person in the tropics. As such, the person in the desert should have much more bacteria on their skin than the person in the tropics would.
Mycoplasma
A. lack peptidoglycan.
B. are the smallest free-living organisms.
C. have sterols in their membranes.
D. are killed by penicillin.
E. lack peptidoglycan, are the smallest free-living organisms AND have sterols in their membranes.
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