Answer:
Stars form large groupings
Explanation:
A large group of stars that have a common origin and are gravitationally bound for some length of time is called star clusters. Star clusters provide a way to study the ages of stars and stellar evolution. There are two categories of star clusters i.e. galactic clusters, and globular clusters.
Out of the given options, we can say that the correct option is (b) "Stars form large groupings".
Answer:
D.4
Explanation:
It contains a carbon atom that bonds to six other atoms instead of the four we have been told carbon is limited to. Atoms form molecules by sharing electrons. Carbon has four electrons that it can share with other atoms
That would be called <span>Defecation.</span>
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
