BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
What is physiology? - Correct Answers ✅the science of the
function of living systems
What is homeostasis? - Correct Answers ✅the
maintenance of a relatively stable internal environment
(especially ECF)
-oscillation around a set point
Who is Walter Cannon? - Correct Answers ✅the father of
physiology
coined the term "homeostasis"
What is the difference between local and reflex control? -
Correct Answers ✅Local control = cells near site of change
initiate response
Reflex control = cells at a distant site control response
What is negative feedback? - Correct Answers ✅stabilizes
variable (correction in opposite direction of change)
What is feedforward mechanism? - Correct Answers
✅control anticipates change
,BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
What is positive feedback? - Correct Answers ✅reinforces
stimulus (NOT homeostatic)
What are the 3 ways cells can communicate long range? -
Correct Answers ✅endocrine - chemical released in blood
and distributed throughout the body
neural - electrical signal travels down neuron then becomes
chemical which travels to target cell
neuroendocrine - electrical signal travels travel down neuron
then becomes chemical signal that is secreted into the blood
What determines what type of receptors ligands will interact
with? - Correct Answers ✅chemical properties of the
ligands
surface receptor = hydrophillic/lipophobic/water soluble
intracellular receptor = hydrophobic/lipophillic/water
insoluble
How can cells change their response to different signals? -
Correct Answers ✅change receptor number or sensitivity
increase = increase expression of gene that codes for
receptor or increase expression of receptor proteins on cell
surface
decrease = internalize surface receptors
change receptor sensitivity = phosphorylation
,BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
How is a GPCR activated? - Correct Answers ✅-signal
molecule binds to receptor and causes conformational
change
-activates G protein by exchanging GDP for GTP
-when GTp binds alpha subunit+GTP dissociates from the B
and gamma subunits
-G alpha subunit turns itself off by hydrolizing GTP
What affect does Cholera Toxin have on the inactivation of G
alpha subunit? - Correct Answers ✅-blocks GTP hydrolysis
(GTPase activity)
-results in persistent activation of adenylate cyclase
What are Cannon's Postulates? - Correct Answers ✅-the
nervous system has a role in maintaining the 'fitness' of the
internal environment
-some systems under tonic control
-some systems are under antagonistic control
-one chemical signal can have different effects in different
tissues
Specificity of neural vs. endocrine control - Correct Answers
✅neural = single target cell or limited number of adjacent
target cells
, BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
endocrine = exposed to all cells but only those which
receptors responsd
Nature of signal for neural vs. endocrine control - Correct
Answers ✅neural = electrical signal that turns chemical
(neurotransmitter)
endocrine = chemical signals
Speed of neural vs. endocrine control - Correct Answers
✅neural = very rapid
endocrine = much slower than neural responses
Duration of action in neural vs. endocrine control - Correct
Answers ✅neural = usually very short
endocrine = longer than neural responses
Coding for stimulus intensity in neural vs endocrine control -
Correct Answers ✅neural = each signal is identical in
strength. Increase intensity by increasing frequency
endocrine = intensity proportional to amount of hormone
secreted
What are the evolutionary trends in the nervous system? -
Correct Answers ✅bilateral symmetry -> cephalization ->
consolidation of PNS -> nerves -> ventral nerve cord ->
Latest Update 2026 (Questions and
Answers-Verified solutions)
What is physiology? - Correct Answers ✅the science of the
function of living systems
What is homeostasis? - Correct Answers ✅the
maintenance of a relatively stable internal environment
(especially ECF)
-oscillation around a set point
Who is Walter Cannon? - Correct Answers ✅the father of
physiology
coined the term "homeostasis"
What is the difference between local and reflex control? -
Correct Answers ✅Local control = cells near site of change
initiate response
Reflex control = cells at a distant site control response
What is negative feedback? - Correct Answers ✅stabilizes
variable (correction in opposite direction of change)
What is feedforward mechanism? - Correct Answers
✅control anticipates change
,BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
What is positive feedback? - Correct Answers ✅reinforces
stimulus (NOT homeostatic)
What are the 3 ways cells can communicate long range? -
Correct Answers ✅endocrine - chemical released in blood
and distributed throughout the body
neural - electrical signal travels down neuron then becomes
chemical which travels to target cell
neuroendocrine - electrical signal travels travel down neuron
then becomes chemical signal that is secreted into the blood
What determines what type of receptors ligands will interact
with? - Correct Answers ✅chemical properties of the
ligands
surface receptor = hydrophillic/lipophobic/water soluble
intracellular receptor = hydrophobic/lipophillic/water
insoluble
How can cells change their response to different signals? -
Correct Answers ✅change receptor number or sensitivity
increase = increase expression of gene that codes for
receptor or increase expression of receptor proteins on cell
surface
decrease = internalize surface receptors
change receptor sensitivity = phosphorylation
,BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
How is a GPCR activated? - Correct Answers ✅-signal
molecule binds to receptor and causes conformational
change
-activates G protein by exchanging GDP for GTP
-when GTp binds alpha subunit+GTP dissociates from the B
and gamma subunits
-G alpha subunit turns itself off by hydrolizing GTP
What affect does Cholera Toxin have on the inactivation of G
alpha subunit? - Correct Answers ✅-blocks GTP hydrolysis
(GTPase activity)
-results in persistent activation of adenylate cyclase
What are Cannon's Postulates? - Correct Answers ✅-the
nervous system has a role in maintaining the 'fitness' of the
internal environment
-some systems under tonic control
-some systems are under antagonistic control
-one chemical signal can have different effects in different
tissues
Specificity of neural vs. endocrine control - Correct Answers
✅neural = single target cell or limited number of adjacent
target cells
, BIOL 373 Midterm 1 (Unit 1, 2 and 3)
Latest Update 2026 (Questions and
Answers-Verified solutions)
endocrine = exposed to all cells but only those which
receptors responsd
Nature of signal for neural vs. endocrine control - Correct
Answers ✅neural = electrical signal that turns chemical
(neurotransmitter)
endocrine = chemical signals
Speed of neural vs. endocrine control - Correct Answers
✅neural = very rapid
endocrine = much slower than neural responses
Duration of action in neural vs. endocrine control - Correct
Answers ✅neural = usually very short
endocrine = longer than neural responses
Coding for stimulus intensity in neural vs endocrine control -
Correct Answers ✅neural = each signal is identical in
strength. Increase intensity by increasing frequency
endocrine = intensity proportional to amount of hormone
secreted
What are the evolutionary trends in the nervous system? -
Correct Answers ✅bilateral symmetry -> cephalization ->
consolidation of PNS -> nerves -> ventral nerve cord ->
