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
Answer:
C
Explanation:
Hope this helped! -Sierra<3
The correct answer is: sea stars
All animals listed above are invertebrates. One of the characteristic of invertebrates are that they are protostomes with the exception of Echinodermata (sea stars). The difference between protostomes and deuterostomes is in their embryonic development (orgin of mouth and anus).
In protostomes the mouth forms first: the oral end of the animal develops from the first developmental opening. On the other hand in deuterostomes the first opening (the blastopore) becomes the anus, and the oral end of the develops from the second opening.
Humans are also deuterostomes.
Greenhouse gases such as carbon dioxide trap heat, helping warm the globe. The surge in carbon dioxide levels due to human activity since the Industrial Revolution is now causing an overall warming of the planet that is having impacts around the globe. And the burning of fuel generates not only carbon dioxide, but also air pollutants that are harmful to human health.
Answer:
It is found only in animal cells.
