Which of the following components of Streptococcus pyogenes are non-antigenic, i.e., do not elicit the host to produce antibodies against it, this it is an important virulence factor?
A. Group specific carbohydrate antigen (Lancefield's Classification)
B. Capsule
C. F protein
D. M protein
E. Streptolysin-O
Answer: B. Capsule
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During a field trip, an instructor touched a moth resting on a tree trunk. The moth raised its forewings to reveal large eyespots on its hind wings. The instructor asked why the moth lifted its wings
One student answered that sensory receptors had fired and triggered a neuronal reflex culminating in the contraction of certain muscles. A second student responded that the behavior might frighten predators. Which statement best describes these explanations? A) The first explanation is correct, but the second is incorrect. B) The first explanation refers to proximate causation, whereas the second refers to ultimate causation. C) The first explanation is biological, whereas the second is philosophical. D) The first explanation is testable as a scientific hypothesis, whereas the second is not. E) Both explanations are reasonable and simply represent a difference of opinion.
Transmission of infectious agents from host to host with the involvement of an intermediate inanimate material is considered to be _____transmission
Fill in the blank(s) with the appropriate word(s).
What will be the approximate shape of the age-structure diagram of a rapidly increasing population?
A) a rectangle B) a pyramid C) an inverted pyramid D) an hourglass
Which of the following is an example of a negative feedback mechanism in regards to hormone regulation?
A. A baby suckles in order to stimulate milk production. B. ADH is released from the pituitary causing water to be reabsorbed in the kidneys. C. The uterine contractions during labor stimulate oxytocin production. D. All of these are examples of a negative feedback mechanism. E. None of these are examples of a negative feedback mechanism.