Answer:
According to the sliding-filament model of contraction, the muscle contraction occur due to the myosin heads propel the actin myofilaments toward the center of the sarcomere. This pulls the Z disks closer together, shortening sarcomere and the entire muscle
Explanation:
In the muscle fiber there are two proteins that facilitate the process of contraction, myosin and actin. Myosin is thicker and more abundant than actin, and its interaction is responsible for the process of muscle contraction.
Both molecules, myosin and actin, form bonds -called cross bridges- where the myosin heads produce the mobilization of actin towards the center of the sarcomere. Z discs are associated with actin myofibrils, so they come close, and promote the shortening of the sarcomere.
This process requires the action of calcium ions, which depolarize the muscle cell and consume energy in the form of ATP.
It should be noted that the myosin and actin molecules do not change their length, but their action causes the muscle fibers to shorten during contraction.
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Types of muscle contraction brainly.com/question/7117064
Dry and arid parts of the world with little to no rain.
The correct answer is D. The theory of natural selection provided a better explanation of the processes that were being observed by the scientists.They observed that the related species birds found on one island were slightly different from that of the other, and certain portions earth, have the species, which were not found anywhere else.
T<span>his reaction, known as nuclear fusion, converts hydrogen atoms into helium. The by-product of nuclear fusion in the </span>Sun's<span> core is a massive volume of </span>energy<span> that gets released and radiates outward toward the surface of the </span>Sun<span> and then into the solar system beyond it.</span>
