As the experts says, solar eclipse do not happen always like lunar
eclipses do that is visible for a long periods of time and are observable. Unlike
solar eclipse, it happens hundreds and thousands of years to see it. Few people
can only see solar eclipse, and those only those people
who are in the small region where the Moon's umbra strike's Earth can witness
one.
Each myofibril is attached at either end of the muscle fiber, when sarcomeres shorten, the muscle fiber Shortens
Mechanism :
Myofibrils are components of the animal skeletal muscles that are made up of sacromeres. They perform the muscular contraction and relaxation via the sliding filament model.
To produce motion, A cross-bridge forms between actin and the myosin heads triggering shortening of the sacromere. This shortening of the sacromere results in the contraction of the muscle fibers, which the net effect can be seen to be a shortening of the fibers.
To learn more about myofibril refer to : brainly.com/question/15461128
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The correct answer is: D. all of the above
A macromolecule is a large molecule present in the cell, composed of a huge number of monomer units with the various functions. There are four main groups: proteins (monomers are amino acids), nucleic acids (monomers are nucleotids) , lipids (monomers are free fatty acids) and carbohydrates (monomers are simple sugars such as glucose).
Some of their functions:
• Provide structure on the cellular levels-lipids (phospholipids) are the main components of the cell membrane;
• store genetic material-nucleic acid (DNA, RNA) are the carriers of genetic information
• store energy-starch is energy source in plants;
• enzymes -proteins often are with the functionin metabolism
• etc.
Answer:
cardiac
Explanation:
An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node). This is a small mass of specialized tissue located in the right upper chamber (atria) of the heart. The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions.
