10) both insulin and glucagon are peptide hormones that target liver cells. the response
of the target cells to each of these two hormones is opposite. this information implies
that
a) the two hormones bind to different cell surface receptors.
b) one hormone binds to a receptor on the cell membrane and the other to an
intracellular receptor.
c) each of the two hormones uses a different second messenger.
d) both hormones interact with receptors at the cell nucleus.
e) the two hormones bind to different receptors and use a different second messenger.
11) which of the following statements is not correct regarding the motor units and their
activation?
a) a motor unit in muscles of gross movement can have thousands of muscle cells.
b) all muscle fibers in a single motor unit are of the same fiber type.
c) a weak contractile stimulus activates fast-twitch motor units.
d) the metabolic capacity of muscle fibers within a motor unit can be altered.
e) at its peak intensity, a contractile stimulus will activate muscle fibers that are easily
fatigued.
12) our perception of the pull of gravity and linear acceleration is the result of
a) changes in the pressure exerted by the cupula on hair cells.
b) vibrations of the tectorial membrane striking hair cells.
c) the pressure exerted by the otolithic organ on hair cells of the maculae.
d) the movement of the otolithic organ within the ampullae of the semicircular canals.
13) during the cardiac cycle,
a) the p wave of the ecg occurs between the first and second heart sounds.
b) the qrs complex of the ecg precedes the increase in ventricular pressure.
c) the third heart sound occurs during atrial systole.
d) the second heart sound coincides with the qrs complex of the ecg.
e) the greatest increase in ventricular pressure occurs during the ejection phase.
14) match the specific enzyme to its class.