Historically, scientists described the human "normal microbiota" as those organisms that could be cultured from the human body. This represents a significant underestimate because_____
a. it is unethical to use human tissue for culturing microbes
b. bacteria can be counted easily, but fungi are more problematic
c. many microbes are resident only on a small portion of the population
d. many microbes cannot be cultured in the laboratory
d. many microbes cannot be cultured in the laboratory
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A Giemsa stain is performed on an eye exudate on a patient with calabar swelling, eosinophilia, and a recent travel history to Africa. L. loa is suspected; however, the sheath in the adult worm recovered does not stain. Which one of the following statements explains this discrepancy?
a. The worm recovered is not L. loa. b. The specimen should have been stained with trichrome stain. c. The Giemsa stain is most likely expired. d. No discrepancy is present. The sheath does not stain with Giemsa stain.
In a songbird species, defending a territory saved the bird 584 calories a day in reduced foraging activity, but cost the bird 656 calories in defense of the territory. Is defending the territory consistent with the prediction from optimal foraging theory, and what can explain this?
A. Yes, because the bird will save 72 calories per day due to defending the territory. B. No, so that demonstrates that optimal foraging theory is not useful. C. No, but there may be non-nutritional benefits to defending territory. D. Yes, because a bird of this species will minimize predation risk by defending the territory. E. No, so it is likely that the researcher made a mistake in data collection.
The lower end of the the uterus narrows and leads to the ________ which opens into the vagina.
A) cervix. B) labia. C) rectum. D) ovary.
Which is not considered a disadvantage of having an exoskeleton? a. Exoskeletons can get relatively heavy
b. Molting is needed to grow. c. Unique construction of the joints for appendages. d. It diminishes the ability to maintain buoyancy.