WITH CORRECT ANSWERS 2025
For a neuron with an initial membrane potential at -70 mV, an increase in the
movement of potassium ions out of that neuron's cytoplasm would result in the .-
CORRECT ANSWER -hyperpolarization of the neuron
The operation of the sodium-potassium "pump" moves . - CORRECT ANSWER -
sodium ions out of the cell and potassium ions into the cell
ATP hydrolysis directly powers the movement of . - CORRECT ANSWER -Na+ out of cells
The "threshold" potential of a membrane is the . - CORRECT ANSWER -
minimum depolarization needed to operate the voltage-gated sodium and
voltage-gated potassium channels
The membrane's permeability to sodium ions is at its maximum at . - CORRECT ANSWER --50mV
The cell is not hyperpolarized; however, repolarization is in progress, as the sodium
channels are closing or closed, and many potassium channels have opened at .-
CORRECT ANSWER -the maximum mV of graph
If you experimentally increase the concentration of K+ inside a cell while maintaining
other ion concentrations as they were, what would happen to the cell's membrane
potential? - CORRECT ANSWER -The membrane potential would become less negative.
If the activity of the sodium-potassium pump was completely stopped, what would
happen to the neuron's membrane potential? - CORRECT ANSWER -slow decrease of resting potential
Tetrodotoxin blocks voltage-gated sodium channels and ouabain blocks sodiumpotassium
pumps. If you added both tetrodotoxin and ouabain to a solution containing
,neural tissue, what responses would you expect? - CORRECT ANSWER -
immediate loss of action potential with gradual loss of resting potential
Chum salmon (Oncorhynchus keta) are born in freshwater environments and then
migrate to the sea. Near the end of their lives, they return to the freshwater stream where
they were born to spawn. In freshwater, water constantly diffuses into the body and ions
are lost from the body. In salt water, body water diffuses out of the body and excess ions
are gained from the water. A salmon's gills have special cells to pump salt in or out of the
body to maintain homeostasis. In response to the salmon's moves between freshwater and
salt water, some cells in the gills are produced and others are destroyed. These changes
made in the cells of the gills during the lifetime of an individual salmon are an example
of which of the following?
A) evolution
B) trade-off
C) acclimatization
D) adaptation - CORRECT ANSWER -C) acclimatization
You observe two female fish of the same species breeding. One female lays 100 eggs
and the other female lays 1000 eggs. Which one of the following is LEAST likely given
the limits of fitness trade-offs?
A) The female laying 100 eggs breeds more often than the female laying 1000 eggs.
B) The female laying 100 eggs lives longer than the female laying 1000 eggs.
C) The eggs from the female laying 1000 eggs have larger yolks than the yolks of the
eggs from the female laying 100 eggs.
D) The female laying 1000 eggs is larger than the female laying 100 eggs. - CORRECT ANSWER -
C) The eggs from the female laying 1000 eggs have larger yolks than the yolks of the
eggs from the female laying 100 eggs
If you were to view a sample of animal tissue under a light microscope and notice an
, extensive extracellular matrix surrounding a tissue, which tissue type would you most
suspect?
A) connective
B) cardiac muscle
C) epithelial
D) nervous
E) striated muscle - CORRECT ANSWER -A) connective
Blood is best classified as connective tissue because . - CORRECT ANSWER -
its cells are separated from each other by an extracellular matrix
The type of muscle tissue surrounding the intestines and blood vessels is . - CORRECT ANSWER -
smooth muscle
A behavioral physiologist is studying the homeostatic control of blood pH. In a trial,
a lizard runs on a treadmill for a set amount of time and the blood pH is measured. The
blood pH drops as carbon dioxide is released into the bloodstream. Which component of
the homeostatic feedback system is responsible for deciding if the blood pH is far enough
from normal that a response is necessary? - CORRECT ANSWER -integrator
Which of the following is an example of negative feedback?
A) During birthing contractions, oxytocin (a hormone) is released and acts to stimulate
further contractions.
B) When a baby is nursing, sucklingHleads to the production of more milk and a
subsequent increase in the secretion of prolactin (a hormone that stimulates lactation).
C) After a blood vessel is damaged, signals are released by the damaged tissues that
activate platelets in the blood. These activated platelets release chemicals that activate
more platelets.
D) When the level of glucose in the blood increases, the pancreas produces and
E)