Water flowing over fish gills exchanges gases with
blood flowing in the opposite direction inside gill
capillaries. This is called__________.
Answer: countercurrent exchange
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Botulinum toxin, or "botox", has become popular for cosmetic surgery. The toxin prevents neurosecretory vesicles from docking at the plasma membrane and releasing neurotransmitter. How would this toxin affect the neuromuscular junction?
A. Since ACh is not released, the muscles stay in a state of repeated contraction. B. Since ACh is not released, the muscles are not activated to contract and remain relaxed. C. Buildup of ACh causes promiscuous activation of all nearby sensory neurons. D. Buildup of ACh leaks back into the brain, creating a calming effect. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? Gather Content/Choose Answer · What do you already know about the botulism? What other information is related to the question? Reflect on Process · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
Which structure is responsible for keeping the fetus from slipping out of the uterus prematurely?
a. cervix b. vagina c. endometrium d. placenta e. umbilical cord
A transgene is a
A) hybrid gene. B) gene that contains no introns. C) bacterial gene that is found in mammalian cells. D) human gene of viral origin. E) gene introduced into an organism by artificial means.
Which of the following cells function in both innate and adaptive immunity?
A) Red blood cells B) White blood cells C) Skin cells D) All of the above