Question

11.
Out of the following the correct diagram of the stripped muscle fibre, is the diagram labelled
If
as:
A
с
a) D
b) B
C C
d) A​

Answer 1

Answer:

Each muscle fibre is long and cylindrical cells, that contain many nuclei, i.e., are multinucleated. Here, labelling E is the nucleus.

The cell membrane is called as sarcolemma. Here, labelling D is sarcolemma. When skeletal muscle is viewed in longitudinal section, it exhibits a distinctive pattern of alternating light and dark bands. The dark-staining bands are called as A-band, sometimes contain a pale region in the middle called as H-zone.

The light staining bands, I bands are bisected by a thin Z-line. This striated pattern in due to the presence of myofibrils in the sarcoplasm. Here, labelling A and labelling F are light and dark bands respectively, while labelling C is myofibril.

The segment of a myofibril from Z-line to Z-line is referred to as sarcomere.

So, the correct answer is 'A- Light band, B- Sarcoplasm, C- Myofibril, D- Sarcolemma, E- Nucleus, F- Dark band'

Explanation: