Answer:
Oxygen
Explanation:
-How fast the heart beats depends on the body's need for oxygen-rich blood. At rest, the SA node causes your heart to beat about 50 to 100 times each minute. During activity or excitement, your body needs more oxygen-rich blood; the heart rate rises to well over 100 beats per minute.
-The heart, like any organ, requires blood for oxygen and other nutrients so it can do its work. The heart does not gather oxygen or nutrients from the blood flowing inside it. Instead, it receives blood from coronary arteries that eventually carry blood into the heart muscle.
Is optic nerve ..........
A biological mechanism called RNAi acts on messenger RNA to silence genes post-transcriptionally (mRNA).
<h3>Explain about the RNA interference?</h3>
The expression of protein-coding genes is regulated by RNA interference (RNAi), also known as post-transcriptional gene silencing (PTGS), a conserved biological response to double-stranded RNA that enhances resistance to both endogenous parasites and external damaging nucleic acids.
When little RNA fragments bind to the messenger RNAs that carry the instructions for translating proteins, they can prevent that translation from occurring. This phenomenon is known as "RNA interference" or "RNAi." The production of proteins and the operation of the immune system are both governed by RNA interference, a naturally occurring phenomenon.
RNA interference (RNAi), which is regarded as a highly selective method for gene silencing, has a great deal of potential for the treatment of numerous pathologic illnesses, including cancer, viral infections, and cardiovascular diseases.
To learn more about RNA interference refer to:
brainly.com/question/7508257
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