WCU PHYS 261 FINAL EXAM NEWEST 2026 ACTUAL
EXAM TEST BANK| PHYS 261 FINAL EXAM REVIEW
WITH COMPLETE 350 REAL EXAM QUESTIONS AND
CORRECT VERIFIED ANSWERS/ ALREADY GRADED A+
(MOST RECENT!!)
1. A negative feedback loop is a mechanism that:
A) Amplifies the initial stimulus to push a variable further
from setpoint
B) Reverses a change in a regulated variable to maintain
homeostasis
C) Has no effect on homeostasis
D) Only occurs in disease states
Correct Answer: B
Rationale: Negative feedback loops reverse a change in a
regulated variable, bringing it back toward the setpoint (e.g.,
body temperature regulation, blood glucose control). Positive
feedback amplifies the stimulus (e.g., childbirth, action potentials).
Homeostasis is primarily maintained by negative feedback.
1
,2. Which of the following is an example of positive feedback?
A) Regulation of blood pressure
B) Regulation of blood glucose by insulin
C) Oxytocin-induced uterine contractions during labor
D) Body temperature regulation through sweating
Correct Answer: C
Rationale: Oxytocin release during labor causes stronger uterine
contractions, which further stimulate oxytocin release, creating a
self-amplifying cycle until delivery. This is positive feedback.
Options A, B, and D are negative feedback mechanisms.
3. The fluid mosaic model describes the plasma membrane as:
A) A rigid, static layer of phospholipids
B) A bilayer of phospholipids with embedded proteins that
can move laterally
C) A single layer of proteins with embedded lipids
D) A solid barrier with no permeability
Correct Answer: B
2
,Rationale: The fluid mosaic model describes the plasma
membrane as a phospholipid bilayer with embedded proteins
that have lateral mobility ("fluid"). The mosaic refers to the
diverse proteins embedded in the membrane. The membrane is
not rigid or static.
4. Which of the following is a function of membrane proteins?
A) Transport of substances
B) Enzymatic activity
C) Signal transduction (receptors)
D) All of the above
Correct Answer: D
Rationale: Membrane proteins have diverse functions: transport
(channels, carriers, pumps), enzymatic activity (catalyzing
reactions at membrane), signal transduction (receptors for
hormones/neurotransmitters), cell-cell recognition, and
intercellular joining.
5. Simple diffusion across a cell membrane requires:
3
, A) A concentration gradient and no membrane protein
(lipid-soluble molecules)
B) A transport protein and energy
C) A transport protein but no energy (facilitated diffusion)
D) Active transport
Correct Answer: A
Rationale: Simple diffusion occurs directly through the lipid
bilayer without a transport protein, driven by a concentration
gradient (high to low). Only small, nonpolar, or lipid-soluble
molecules (O₂, CO₂, steroids) can use simple diffusion. Facilitated
diffusion requires a protein but no energy.
6. Which transport process requires both a membrane protein
and direct ATP hydrolysis?
A) Simple diffusion
B) Facilitated diffusion
C) Primary active transport
D) Osmosis
Correct Answer: C
4
EXAM TEST BANK| PHYS 261 FINAL EXAM REVIEW
WITH COMPLETE 350 REAL EXAM QUESTIONS AND
CORRECT VERIFIED ANSWERS/ ALREADY GRADED A+
(MOST RECENT!!)
1. A negative feedback loop is a mechanism that:
A) Amplifies the initial stimulus to push a variable further
from setpoint
B) Reverses a change in a regulated variable to maintain
homeostasis
C) Has no effect on homeostasis
D) Only occurs in disease states
Correct Answer: B
Rationale: Negative feedback loops reverse a change in a
regulated variable, bringing it back toward the setpoint (e.g.,
body temperature regulation, blood glucose control). Positive
feedback amplifies the stimulus (e.g., childbirth, action potentials).
Homeostasis is primarily maintained by negative feedback.
1
,2. Which of the following is an example of positive feedback?
A) Regulation of blood pressure
B) Regulation of blood glucose by insulin
C) Oxytocin-induced uterine contractions during labor
D) Body temperature regulation through sweating
Correct Answer: C
Rationale: Oxytocin release during labor causes stronger uterine
contractions, which further stimulate oxytocin release, creating a
self-amplifying cycle until delivery. This is positive feedback.
Options A, B, and D are negative feedback mechanisms.
3. The fluid mosaic model describes the plasma membrane as:
A) A rigid, static layer of phospholipids
B) A bilayer of phospholipids with embedded proteins that
can move laterally
C) A single layer of proteins with embedded lipids
D) A solid barrier with no permeability
Correct Answer: B
2
,Rationale: The fluid mosaic model describes the plasma
membrane as a phospholipid bilayer with embedded proteins
that have lateral mobility ("fluid"). The mosaic refers to the
diverse proteins embedded in the membrane. The membrane is
not rigid or static.
4. Which of the following is a function of membrane proteins?
A) Transport of substances
B) Enzymatic activity
C) Signal transduction (receptors)
D) All of the above
Correct Answer: D
Rationale: Membrane proteins have diverse functions: transport
(channels, carriers, pumps), enzymatic activity (catalyzing
reactions at membrane), signal transduction (receptors for
hormones/neurotransmitters), cell-cell recognition, and
intercellular joining.
5. Simple diffusion across a cell membrane requires:
3
, A) A concentration gradient and no membrane protein
(lipid-soluble molecules)
B) A transport protein and energy
C) A transport protein but no energy (facilitated diffusion)
D) Active transport
Correct Answer: A
Rationale: Simple diffusion occurs directly through the lipid
bilayer without a transport protein, driven by a concentration
gradient (high to low). Only small, nonpolar, or lipid-soluble
molecules (O₂, CO₂, steroids) can use simple diffusion. Facilitated
diffusion requires a protein but no energy.
6. Which transport process requires both a membrane protein
and direct ATP hydrolysis?
A) Simple diffusion
B) Facilitated diffusion
C) Primary active transport
D) Osmosis
Correct Answer: C
4
