Asked by allen myers on Sep 23, 2024
Verified
Which of the following does NOT occur as a sarcomere shortens during muscle contraction?
A) The thin and thick myofilaments shorten in length.
B) The I bands shorten.
C) The Z lines (discs) move closer together.
D) The H zone shortens.
E) All of these occur as a sarcomere shortens.
Sarcomere
The basic unit of a muscle's cross-striated myofibril and the site of muscle contraction.
Myofilaments
The filaments of myofibrils, constructed from proteins, primarily actin, and myosin, which are essential for muscle contraction.
I Bands
I Bands are the light-appearing regions of a sarcomere in muscle fibers, reflecting areas where thin filaments do not overlap with thick filaments.
- Describe the process and components involved in muscle contraction.
Verified Answer
SG
Samantha Gonsalves3 days ago
Final Answer :
A
Explanation :
During muscle contraction, the thin and thick myofilaments do not actually shorten in length. Instead, they slide past one another, causing the sarcomere to shorten. The other options are all correct, as the I bands shorten, the Z lines move closer together, and the H zone shortens as the sarcomere contracts.
Learning Objectives
- Describe the process and components involved in muscle contraction.