The sarcomere is the region of a myofibril between two successive:
Correct answer: C. Z-Line
- A. I-Line
- B. A-Line
- C. Z-Line
- D. M-Line
Explanation
Option C is correct. The sarcomere is the region of a myofibril between two successive Z-lines. A myofibril is a long, thin strand of muscle tissue that is made up of sarcomeres. Sarcomeres are the basic contractile units of muscle tissue. The Z-line is a thin, dark line that marks the boundary of a sarcomere. It is made up of a protein called α-actinin, which helps to anchor the actin filaments in place. I-band: The I-band is the light-colored band in the sarcomere. It contains only actin filaments. A-band: The A-band is the dark-colored band in the sarcomere. It contains both actin and myosin filaments. M-line: The M-line is a thin line in the center of the A-band. It is made up of a protein called myomesin, which helps to stabilize the myosin filaments.
This question appeared on the KMU MDCAT 2023 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Muscle Contraction questions
During muscle relaxation, the calcium ions are:
Contraction can be sustained for a long period of time by:
Sarcomere is part of myofibril between:
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:
Muscle fatigue results due to deficiency of _ and excess accumulation of _.
Thick filaments in skeletal muscles are composed of: