All AP Biology Resources
Example Questions
Example Question #32 : Understanding Muscle Cells
Which of the following best describes how type IIb skeletal muscle tissue differs from type IIa skeletal muscle tissue?
Type IIb tissue is anaerobic while type IIa tissue is aerobic
Type IIb tissue has no mitochondria while type IIa tissue has many mitochondria
Type IIb tissue has many mitochondria while type IIa tissue has fewer mitochondria
Type IIb tissue is aerobic while type IIa tissue is anaerobic
Type IIb tissue is anaerobic while type IIa tissue is aerobic
Type IIb skeletal muscle tissue is a subtype of skeletal muscle tissue that is anaerobic and has fewer mitochondria than type IIa.
Example Question #33 : Understanding Muscle Cells
Which of the following best describes type IIx skeletal muscle contraction?
Sustains short bursts of anaerobic contraction
It is the fastest muscle type in humans
All of these
It contracts more quickly than aerobic muscles
All of these
Type IIx skeletal muscle tissue is the fastest muscle type in humans. This subtype of skeletal muscle tissue is characterized by short bursts of anaerobic contraction. It is also able to contract more quickly than aerobic muscles.
Example Question #34 : Understanding Muscle Cells
In regard to muscles, which of the following statements best defines a sarcomere?
Sarcomeres are the areas between two I bands
Sarcomeres are the areas between Z lines
Sarcomeres include A bands and I bands
Sarcomeres are Z lines
Sarcomeres are the areas between Z lines
Sarcomeres are considered to be the functional units of muscles and are defined as the areas between two Z lines. Sarcomeres are the units that are responsible for the striated appearance of certain muscle types (skeletal and cardiac).
Example Question #35 : Understanding Muscle Cells
Which of the following best represents the generic term for a muscle cell?
Myoblast
Sarcomere
Myofibril
Myocyte
Myocyte
Muscle cells are often referred to as “myocytes.” Myocytes are tubular cells that develop during a process called myogenesis and specialize based on their association with specific muscle types.
Example Question #504 : Cellular Biology
Which of the following pairs of two motor proteins are critical in human muscle contraction?
Actin and kinesin
Myosin and kinesin
Kinesin and dynein
Actin and myosin
Actin and myosin
Human muscle contraction relies on the action of the motor proteins actin and myosin. Muscles contract through the sliding of myosin and actin filaments along one another.
Example Question #35 : Understanding Muscle Cells
Which of the following best describes the difference between the sarcoplasmic reticulum (SR) in myocytes and the smooth endoplasmic reticulum (smooth ER) in other cells?
The SR synthesizes molecules and the smooth ER is involved in calcium storage
The SR is significantly larger than the smooth ER
The SR is involved in calcium storage and the smooth ER synthesizes molecules
There are no differences between the SR and the smooth ER
The SR is involved in calcium storage and the smooth ER synthesizes molecules
The sarcoplasmic reticulum (SR) is a specialized type of smooth endoplasmic reticulum in striated muscle tissue. The SR has a different function than the smooth ER. The SR is involved in calcium ion storage that is critical in contraction while the smooth ER synthesizes new molecules.
Example Question #37 : Understanding Muscle Cells
Myocytes and muscle tissue are formed during which of the following stages of embryogenesis?
Myogenesis
Neurulation
Gastrulation
Organogenesis
Myogenesis
During embryogenesis, the process of myogenesis forms myocytes and muscle tissue.
Example Question #39 : Understanding Muscle Cells
Which of the following cellular structures in muscle tissue is comparable to cytoplasm?
Sarcoplasm
Sarcomere
Sarcoplasmic reticulum
Myofibrils
Sarcoplasm
The sarcoplasm in muscle cells is comparable to the cytoplasm in other types of cells. The sarcoplasm is specialized in the high amount of myoglobin present. Its specialized regulation of calcium ion concentrations controls muscle contractions.
Example Question #36 : Understanding Muscle Cells
Which of the following best describes “intercalated disks”?
They form the boundaries of actin filaments
Portions of the cell that contain high quantities of myoglobin
They are observable characteristics of striated muscle tissue
Structures that connect cardiac muscle cells
Structures that connect cardiac muscle cells
Intercalated disks are structures that connect cardiac muscle cells, allowing them to work together and communicate within the heart. Intercalated disks are made up of different types of cell junctions and are observable under the microscope. This makes cardiac muscle tissue distinguishable.
Example Question #41 : Understanding Muscle Cells
Which of the following is responsible for the red appearance of some muscles?
They are anaerobic
They have few mitochondria
They contain large quantities of myoglobin
They are fast twitch—fast contraction—muscles
They contain large quantities of myoglobin
Muscle tissue can be divided into red—fast twitch—and white—slow twitch—muscle types. Red muscles have many capillaries, mitochondria, and myoglobin. Red muscles also perform aerobic activity.