BIOS 252 FINAL EXAM 2025
BIOS 252 FINAL EXAM 2025 WITH GUARANTEED ACCURATE ANSWERS
Which of the following is a recognized function of skeletal muscle?
1) A) guard body entrances and exits
B) maintain posture
C) maintain body temperature
D) produce movement
E) all of the above - Accurate ✔✔✔ E
Nerves and blood vessels that service the muscle fibers are located in the
connective tissues of the
A) myofibrils.
B) sarcolemma.
,C) endomysium.
D) sarcomere.
E) perimysium. - Accurate ✔✔✔ E
Which of the following best describes the term sarcoplasmic reticulum?
A) largely made of myosin molecules
B) storage and release site for calcium ions
C) thin filaments are anchored here
D) protein that accounts for elasticity of resting muscle
E) repeating unit of striated myofibrils - Accurate ✔✔✔ B
Interactions between actin and myosin filaments of the sarcomere are
responsible for
A) the conduction of neural stimulation to the muscle fiber.
B) muscle fatigue.
C) the striped appearance of skeletal muscle.
D) muscle contraction.
E) muscle relaxation. - Accurate ✔✔✔ D
The region of the sarcomere that always contains thin filaments is the
A) Z line.
B) A band.
,C) H band.
D) M line.
E) I band. - Accurate ✔✔✔ E
At rest, active sites on the actin are blocked by
A) calcium ions.
B) troponin molecules.
C) tropomyosin molecules.
D) myosin molecules.
E) ATP molecules. - Accurate ✔✔✔ C
Cross-bridges are portions of
A) actin molecules.
B) myosin molecules.
C) tropomyosin molecules.
D) troponin molecules.
E) calcium ions. - Accurate ✔✔✔ B
When a skeletal muscle fiber contracts, A) the zones of overlap get
larger.
B) the H bands and I bands get smaller.
C) the Z lines get closer together. D) the width of the A band remains
constant.
, E) all of the above - Accurate ✔✔✔ E
The following is a list of the events that occur during a muscle
contraction. 1. Myosin cross-bridges bind to the actin.
2. The free myosin head splits ATP.
3. Calcium ion is released from the sarcoplasmic reticulum.
4. The myosin head pivots toward the center of the sarcomere.
5. Calcium ion binds to troponin. 6. The myosin head binds an ATP
molecule and detaches from the actin.
The correct sequence of these events is
A) 3, 5, 1, 2, 4, 6.
B) 1, 4, 6, 2, 3, 5.
C) 1, 3, 5, 4, 6, 2.
D) 5, 1, 4, 6, 2, 3.
E) 3, 5, 1, 4, 6, 2. - Accurate ✔✔✔ E
Active sites on the actin become available for binding after
A) troponin binds to tropomyosin. B) calcium binds to tropomyosin. C)
myosin binds to troponin.
D) calcium binds to troponin.
E) actin binds to troponin. - Accurate ✔✔✔ D
In an isotonic contraction,
BIOS 252 FINAL EXAM 2025 WITH GUARANTEED ACCURATE ANSWERS
Which of the following is a recognized function of skeletal muscle?
1) A) guard body entrances and exits
B) maintain posture
C) maintain body temperature
D) produce movement
E) all of the above - Accurate ✔✔✔ E
Nerves and blood vessels that service the muscle fibers are located in the
connective tissues of the
A) myofibrils.
B) sarcolemma.
,C) endomysium.
D) sarcomere.
E) perimysium. - Accurate ✔✔✔ E
Which of the following best describes the term sarcoplasmic reticulum?
A) largely made of myosin molecules
B) storage and release site for calcium ions
C) thin filaments are anchored here
D) protein that accounts for elasticity of resting muscle
E) repeating unit of striated myofibrils - Accurate ✔✔✔ B
Interactions between actin and myosin filaments of the sarcomere are
responsible for
A) the conduction of neural stimulation to the muscle fiber.
B) muscle fatigue.
C) the striped appearance of skeletal muscle.
D) muscle contraction.
E) muscle relaxation. - Accurate ✔✔✔ D
The region of the sarcomere that always contains thin filaments is the
A) Z line.
B) A band.
,C) H band.
D) M line.
E) I band. - Accurate ✔✔✔ E
At rest, active sites on the actin are blocked by
A) calcium ions.
B) troponin molecules.
C) tropomyosin molecules.
D) myosin molecules.
E) ATP molecules. - Accurate ✔✔✔ C
Cross-bridges are portions of
A) actin molecules.
B) myosin molecules.
C) tropomyosin molecules.
D) troponin molecules.
E) calcium ions. - Accurate ✔✔✔ B
When a skeletal muscle fiber contracts, A) the zones of overlap get
larger.
B) the H bands and I bands get smaller.
C) the Z lines get closer together. D) the width of the A band remains
constant.
, E) all of the above - Accurate ✔✔✔ E
The following is a list of the events that occur during a muscle
contraction. 1. Myosin cross-bridges bind to the actin.
2. The free myosin head splits ATP.
3. Calcium ion is released from the sarcoplasmic reticulum.
4. The myosin head pivots toward the center of the sarcomere.
5. Calcium ion binds to troponin. 6. The myosin head binds an ATP
molecule and detaches from the actin.
The correct sequence of these events is
A) 3, 5, 1, 2, 4, 6.
B) 1, 4, 6, 2, 3, 5.
C) 1, 3, 5, 4, 6, 2.
D) 5, 1, 4, 6, 2, 3.
E) 3, 5, 1, 4, 6, 2. - Accurate ✔✔✔ E
Active sites on the actin become available for binding after
A) troponin binds to tropomyosin. B) calcium binds to tropomyosin. C)
myosin binds to troponin.
D) calcium binds to troponin.
E) actin binds to troponin. - Accurate ✔✔✔ D
In an isotonic contraction,
