Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
The muscles are composed inside mainly of fibers, filaments and proteins, where it is important to consider the <u>length-tension</u> relationship of the thick and thin filaments to know the tension.
<h3>What is muscle contraction?</h3>
It is an organized and natural event that takes place at the level of the muscles when the fibers and proteins inside them come together, and tension is produced in the area.
<h3>Characteristics of muscle contraction</h3>
- In a muscle contraction, a tension is generated that depends on the length-tension relationship, which causes a displacement of the muscle filaments.
- The proteins actin and myosin join together, and a force is generated so that the final movement is achieved.
- To know the tension, the muscle changes length and measurable external work is produced from the force and distance traveled.
Therefore, we can conclude that the contraction allows us to make movements to reach and carry our extremities to different places.
Learn more about muscle contraction here: brainly.com/question/14625676
Answer: the answer is C
Explanation:
Pancreatic proteases (such as trypsin and chymotrypsin) - which help to digest proteins.
It has to be B. hands, said