Answer:
The Z lines and H- zone shortens during the muscle contraction.
Explanation:
Sarcomere is the area between the two Z lines. The Z- lines are present in the centre of I - band and H - zone is present in the A - band. The actin filaments which are thin filaments present in I- band and contracts, slide over the myosin filament during contraction.
The I - band, H- zones are became shortens as they are thin than the A- band. It is anisotropic band having thick myosin filaments. They are not flexible and remain in its constant shape during the muscle contraction.
After the muscle contraction, the A- band and the H- zone comes to their original shape. In other words, the sarcomere shortens and comes back during muscle contraction, and relaxation.
I believe the answer is protein
D. the 4 types of tissues in the body are: muscle, nerve, connective and epithelial
The answer is D) unlimited flow of water into or out of the cell for #9.
For #10, the answer is C) endocytosis and exocytosis.
Answer:
A. the speed of the light ray is the same in air and Medium A.
Explanation:
