Match each description to its correct term.
-contractile units of muscle
A)Z line
B)ATP
C)mitochondria
D)actin
E)sarcomeres
F)phosphate group
G)myofibrils
H)smooth muscle
I)thick filaments
J)myosin
K)Sphincter

Question

Quizplus · Accepted Answer

Sarcomeres are the contractile units of muscle.

Answer: G
 Myofibrils are the thread-like structures within muscle cells that contain the sarcomeres.

Answer: I
 Thick filaments are made of myosin and are an important component of muscle contraction.

Answer: J
 Myosin is the protein molecule that interacts with actin to cause muscle contraction.

Answer: H
 Smooth muscle is a type of muscle tissue that lacks sarcomeres, so it does not contain actin and myosin filaments.

Answer: K
 A sphincter is a circular muscle that constricts an opening or tube in the body, such as the muscles that control the flow of urine or feces. None of the other terms are related to this function.

Match Each Description to Its Correct Term