Which of these is the best description of a virus?
A. an invasive cell
B. a noncellular living organism
C. the smallest bacteria known
D. chemical complexes of RNA or DNA protected by a protein shell
E. a member of the kingdom Virusae
Answer: D
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In the glomerulus, blood is filtered under pressure through a filtration barrier made up of (select all correct choices):
A. capillary endothelial cells. B. a basal lamina. C. a layer of podocytes. D. renal corpuscles. E. loops of Henle.
Where does the copper used for wiring and plumbing come from?
a. Most copper is found in ocean sediments. b. Most copper is mined from the ground. c. Most copper is found along riverbanks. d. All copper is mined from the surface. e. All copper is manufactured synthetically in factories.
Autoimmune diseases are disorders where the immune system fails to distinguish _______ from foreign ones.
What will be an ideal response?
Imagine that a mutant mouse has a defect in the distribution of norepinephrine receptors, so that all the arteries and arterioles carry the type of norepinephrine receptor normally found around the brain and heart. What would you predict for this mouse in response to hemorrhage?
A. Blood vessels near the brain and heart will constrict, while blood vessels elsewhere will be dilated. B. Vasoconstriction near the brain and heart will prevent enough blood from reaching those organs. C. Blood vessels near the brain and heart will be dilated, while blood vessels elsewhere will constrict. D. Vessels throughout the body will stay dilated, resulting in inadequate blood flow to the brain and heart.