Answer:
The shortcomings or drawbacks of cell theory are: Viruses are considered as acellular entities or organisms that do not have cell machinery, yet they are taken into account as organisms in this cell theory. Matthias Schleiden and Theodor Schwann did not know the mechanism of the cell.
Explanation:
Arteries are part of the circulatory system in the human
body that transports nutrients and oxygen to every cell of the body. It is also
a vessel that carries blood away from the heart and toward other organs and
tissues. If the smooth muscles in the arteries will be relaxed it decreases the
blood pressure.
<span>the botancal name would be Piper nigrum</span>
Answer:
The correct answer will be options
1. The position of the tropomyosin threads shift
2. Exposing myosin binding sites
3. Allowing the myosin head to attach to the actin filament
Explanation:
Calcium plays an important role in the contraction of muscles especially in the formation of the cross-bridge between myosin and actin filaments.
In the presence of calcium, myosin head binds the actin filament as calcium binds to the troponin which changes the configuration of the troponin which releases the tropomyosin from the myosin-binding site on actin.
Once the myosin binding site is freed, myosin binds the site and causes muscle contraction due to ATP hydrolysis.
Thus, the selected options are the correct answer.
