The smallest contractile unit of muscle contraction, called a sarcomere, is the area between two?
Correct answer: C. Z line
- A. H zone
- B. M line
- C. Z line
- D. Z zone
Explanation
The correct answer is the Z line. The sarcomere is the basic contractile unit of muscle fibers and is defined by the area between two Z lines. These lines serve as anchor points for actin filaments and help maintain the structure during contraction. The H zone and M line are internal components of the sarcomere that do not define its boundaries. The term 'Z zone' is not used in muscle anatomy; thus, it is not a correct option.
Last updated
About Muscle Contraction
Muscle contraction is explained by the sliding filament model, in which myosin heads pull actin filaments within sarcomeres using ATP. The topic covers calcium, troponin, tropomyosin, the neuromuscular junction and relaxation, with attention to how filament length stays almost constant while the sarcomere shortens.
Practise Support and Movement
738 free Support and Movement MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A smallest contractile unit of muscle contraction called sarcomere is the area between two:
According to the sliding filament hypothesis, the release of_ from the sarcoplasmic reticulum causes the reorientation of certain components in the thin filament, permitting them to bind with extension from the thick myosin filaments:
According to the sliding filament theory, a muscle shortens because
According to the sliding filament theory, when muscle fibers are stimulated by the nervous system, which of the following changes occurs?
ATP is required for muscle contraction for