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
Answer:
a. All of the answers are correct.
Explanation:
During conjugation a bacteria transfers it's genetic material to another bacteria. The genetic material has genes in a particular order so we can easily know the order of the genes through experimentation. The transfer of genes occurs as per the time allowed. If two genes are nearby then they will be transferred one after the other.
For example in the given question, gene A was transferred to recipient bacteria in 26 minutes, gene M was transferred in 37 minutes while gene T was transferred in 45 minutes, it simply means that the order of genes is A M T. Gene M was transferred to another bacteria after A was transferred because time required to transfer it is 37 minutes which is less than time required to transfer A which is 26 minutes. Gene T took maximum time to get transferred so it will be last to be transferred.
After calculation, we can easily infer that the genetic distance between A and M is 11 minutes (37 minutes - 26 minutes = 11 minutes). Similarly we can get genetic distance between A and T as 19 minutes and between M and T as 8 minutes. So all the given options are correct.
Well... a revolution for one.
