Answer:
The correct order is: 6) Sarcoplasmic reticulum releases calcium ions, 2) Calcium ions bind to troponin, 5) Tropomyosin moves to expose active sites of actin, 4) ATP is split into ADP and P, 1) Myosin head binds to actin, 7) ADP and P released from myosin, 3) Myosin cross-bridges bend, pulling actin toward center of sarcomere.
Explanation:
The ability to contract is an important property of the muscle cells and is fundamental to animals because muscles not only make locomotion possible but are also responsible for the correct functioning of organs (including the heart).
The mechanism behind muscle contraction is the sliding of filaments in a structure called sarcomere, which mostly involves the presence of actin and myosin filaments.
For muscle contraction to happen, there needs to be a <u>stimulus coming from the nerve that innervates said muscle</u>. This stimulus generates the release of <u>calcium ions</u> that will bind to a protein called troponin and will lead to the exposure of the active site of actin so it can bind to the myosin head. <u>This process requires ATP</u>.
Lymphocytes are white blood cells that are part of the body's immune system
In his experiment mendel first crossed tall and short peas plant and noticed that the F1 plants were all tall. in the second experiment he crossed the the F1 plants and noticed that short plants reappeared in the rate of 25% in F2 generation. in his third experiment he crossed he crossed F2 plants and noticed that when he crossed some tall plants with the shot plants the F3 generation contained short plant in frequency of 50%. after this observations mendel concluded that there were genes that could be only expressed in homozygous state but not in heterozygous state. these genes were later referred to as recessive alleles wheres the genes that prevented the expression of recessive genes were later referred to as dominant genes.
