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WSU Biology 251 Exam 1updated 2024
Which of the following statements about homeostasis is FALSE?
a.) Homeostasis is the maintenance of the internal environment
b.) The organ systems work together to maintain homeostasis
c.) Illness can result if homeostasis is disrupted
d.) The primary mechanism to maintain homeostasis is positive feedback
e.) The extracellular fluid is maintained in a state compatible for life - ANS>> d.) The
primary mechanism to maintain homeostasis is positive feedback
What type of cell produces myelin sheaths around axons of neurons in the central
nervous system? - ANS>> oligodendrocyte
In a neuron, where are voltage-gated calcium channels located? - ANS>> axon
termnial
The body fluid compartment with a high potassium and protein concentration is
_________. - ANS>> intracellular fluid
In most homeostasis mechanisms, a ________ detects a change in a regulated
variable and sends that information to a(n) _________ which relays signals to a(n)
_________. - ANS>> sensor; integrating; center; effector
The function of a second messenger system is to - ANS>> amplify the response of the
first messenger
Parasympathetic preganglionic neurons release the neurotransmitter _______;
sympathetic preganglionic neurons release the neurotransmitter ______. - ANS>>
acetylcholine; acetylcholine
The electrochemical gradient for sodium across the membrane is such that the net flux
for sodium movement is directed ________, thereby causing the cell's membrane
potential to become more _______. - ANS>> inward; positive
Which of the following cells would have a greater electrical attraction for sodium ions to
enter the cell?
a.) cell with membrane potential =-70mV
b.) cell with membrane potential = 0mV
c.) cell with membrane potential =-90mV
d.) cell with membrane potential =+20mV
e.) cell with membrane potential =-50mV - ANS>> c.) cell with membrane potential =-
90mV
As the number of receptors on the cell membrane decreases, the response of the
target cell will ________. - ANS>> decrease
