Answer:
Veins
1l carry blood from tissue of the body to the heart
2) are usually found closer beneath the skin
3) are less muscular then arteries
4) collapse if blood flow stops
arteries
1) carry blood back away from the heart to the tissue of the body.
2) found deeper within the body
3) are more muscular then veins
4) would generally remain open even if blood stops because of it's muscular structure.
The water may be polluted and the wetness of the dirt may not be suitible for numerous plants
<em>Answer: Mitochondria are found in all body cells, with the exception of a few. There are usually multiple mitochondria found in one cell, depending upon the function of that type of cell. Mitochondria are located in the cytoplasm of cells along with other organelles of the cell.</em>
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.
Learn more:
Types of muscle contraction brainly.com/question/7117064
