Answer:
The correct answer will be option-D.
Explanation:
Calcium plays an important role in muscle contraction as they are released from the sarcoplasmic reticulum after they receive electric impulse.
Calcium triggers the muscle contraction cycle as these calcium ions bind to the troponin-tropomyosin complex. This binding exposes the myosin-binding site on the actin on which high energy myosin binds and cross-bridge is formed.
This cross-bridge formation causes the contraction of the sarcomere and therefore muscle contracts.
Thus, option-D is the correct answer.
the internal structures provide shapes and support to a variety of living organisms both unicellular and multicellular
<span>They do not have a phloem or xylem.</span>
bacteria can live in hotter and colder temperatures than humans but they do best in a warm moist protein-rich environment that is pH neutral or slightly acidic
L*W*H should be your answer
