BIOL251 Human Anatomy & Physiology I w/Lab | Module 5
Review-200 Practice Questions with Verified Answers and
Explanations-Latest Update 2026/2027 | LockDown Browser
Ready | A+ Graded
1. Which of the following is a characteristic of all muscle tissue?
A. Voluntary control
B. Striated appearance
C. Excitability
D. Multinucleated cells
Answer: C
Explanation: All muscle tissues share four key properties: excitability (responsiveness to stimuli),
contractility, extensibility, and elasticity. Voluntary control applies only to skeletal muscle, striations are
seen in skeletal and cardiac but not smooth muscle, and multinucleation is specific to skeletal muscle
fibers.
2. What types of muscle tissue are under involuntary control?
A. Skeletal and cardiac
B. Smooth and cardiac
C. Skeletal and smooth
D. All muscle types
Answer: B
Explanation: Smooth muscle (found in walls of hollow organs) and cardiac muscle (found in the heart)
are under involuntary control. Skeletal muscle is under voluntary control.
,3. Under the microscope, which types of muscle appear striated or striped?
A. Skeletal and smooth
B. Smooth and cardiac
C. Skeletal and cardiac
D. Only skeletal
Answer: C
Explanation: Both skeletal and cardiac muscle exhibit striations due to the organized arrangement of
actin and myosin filaments into sarcomeres. Smooth muscle lacks striations.
4. The connective tissue layer that surrounds an individual muscle fiber is called the:
A. Epimysium
B. Perimysium
C. Endomysium
D. Fascia
Answer: C
Explanation: The endomysium is the delicate layer of areolar connective tissue that surrounds each
individual muscle fiber. The perimysium surrounds fascicles (bundles of fibers), and the epimysium
surrounds the entire muscle.
5. A fascicle is best described as:
A. A single muscle cell
B. A bundle of muscle fibers
C. A connective tissue covering
,D. A contractile protein
Answer: B
Explanation: A fascicle is a bundle of muscle fibers (muscle cells) bound together by the perimysium.
Multiple fascicles make up a whole muscle.
6. The sarcolemma refers to the:
A. Cytoplasm of a muscle cell
B. Plasma membrane of a muscle fiber
C. Smooth endoplasmic reticulum in muscle
D. Contractile unit of a muscle
Answer: B
Explanation: The sarcolemma is the specialized plasma membrane of a muscle fiber (muscle cell). The
cytoplasm is called sarcoplasm, the smooth ER is called sarcoplasmic reticulum, and the contractile unit
is the sarcomere.
7. The sarcoplasmic reticulum stores which ion that is critical for muscle contraction?
A. Sodium
B. Potassium
C. Calcium
D. Magnesium
Answer: C
, Explanation: The sarcoplasmic reticulum (SR) is a specialized smooth endoplasmic reticulum that stores
and releases calcium ions (Ca²⁺). The release of Ca²⁺ from the SR triggers the sliding filament mechanism
of muscle contraction.
8. The functional contractile unit of a skeletal muscle fiber is the:
A. Myofibril
B. Sarcomere
C. Myofilament
D. Ttubule
Answer: B
Explanation: The sarcomere is the basic functional unit of skeletal muscle contraction. It is the region
between two Zdiscs and contains the organized arrangement of actin and myosin filaments.
9. Which of the following proteins makes up the thick filaments in skeletal muscle?
A. Actin
B. Myosin
C. Troponin
D. Tropomyosin
Answer: B
Explanation: Thick filaments are composed primarily of the protein myosin. Each myosin molecule has a
tail and two globular heads that form crossbridges with actin during contraction. Actin is the primary
component of thin filaments.
Review-200 Practice Questions with Verified Answers and
Explanations-Latest Update 2026/2027 | LockDown Browser
Ready | A+ Graded
1. Which of the following is a characteristic of all muscle tissue?
A. Voluntary control
B. Striated appearance
C. Excitability
D. Multinucleated cells
Answer: C
Explanation: All muscle tissues share four key properties: excitability (responsiveness to stimuli),
contractility, extensibility, and elasticity. Voluntary control applies only to skeletal muscle, striations are
seen in skeletal and cardiac but not smooth muscle, and multinucleation is specific to skeletal muscle
fibers.
2. What types of muscle tissue are under involuntary control?
A. Skeletal and cardiac
B. Smooth and cardiac
C. Skeletal and smooth
D. All muscle types
Answer: B
Explanation: Smooth muscle (found in walls of hollow organs) and cardiac muscle (found in the heart)
are under involuntary control. Skeletal muscle is under voluntary control.
,3. Under the microscope, which types of muscle appear striated or striped?
A. Skeletal and smooth
B. Smooth and cardiac
C. Skeletal and cardiac
D. Only skeletal
Answer: C
Explanation: Both skeletal and cardiac muscle exhibit striations due to the organized arrangement of
actin and myosin filaments into sarcomeres. Smooth muscle lacks striations.
4. The connective tissue layer that surrounds an individual muscle fiber is called the:
A. Epimysium
B. Perimysium
C. Endomysium
D. Fascia
Answer: C
Explanation: The endomysium is the delicate layer of areolar connective tissue that surrounds each
individual muscle fiber. The perimysium surrounds fascicles (bundles of fibers), and the epimysium
surrounds the entire muscle.
5. A fascicle is best described as:
A. A single muscle cell
B. A bundle of muscle fibers
C. A connective tissue covering
,D. A contractile protein
Answer: B
Explanation: A fascicle is a bundle of muscle fibers (muscle cells) bound together by the perimysium.
Multiple fascicles make up a whole muscle.
6. The sarcolemma refers to the:
A. Cytoplasm of a muscle cell
B. Plasma membrane of a muscle fiber
C. Smooth endoplasmic reticulum in muscle
D. Contractile unit of a muscle
Answer: B
Explanation: The sarcolemma is the specialized plasma membrane of a muscle fiber (muscle cell). The
cytoplasm is called sarcoplasm, the smooth ER is called sarcoplasmic reticulum, and the contractile unit
is the sarcomere.
7. The sarcoplasmic reticulum stores which ion that is critical for muscle contraction?
A. Sodium
B. Potassium
C. Calcium
D. Magnesium
Answer: C
, Explanation: The sarcoplasmic reticulum (SR) is a specialized smooth endoplasmic reticulum that stores
and releases calcium ions (Ca²⁺). The release of Ca²⁺ from the SR triggers the sliding filament mechanism
of muscle contraction.
8. The functional contractile unit of a skeletal muscle fiber is the:
A. Myofibril
B. Sarcomere
C. Myofilament
D. Ttubule
Answer: B
Explanation: The sarcomere is the basic functional unit of skeletal muscle contraction. It is the region
between two Zdiscs and contains the organized arrangement of actin and myosin filaments.
9. Which of the following proteins makes up the thick filaments in skeletal muscle?
A. Actin
B. Myosin
C. Troponin
D. Tropomyosin
Answer: B
Explanation: Thick filaments are composed primarily of the protein myosin. Each myosin molecule has a
tail and two globular heads that form crossbridges with actin during contraction. Actin is the primary
component of thin filaments.
