Protein
Proteins are the most versatile
macromolecules in living systems and they play important roles in essentially
all biological processes. Protein makes up the capsid of a virus. The infective
extracellular form of a virus known as a virion contains at
least one unique protein synthesized by specific genes in the nucleic acid of
that virus. In almost all viruses, at least one of these proteins forms a shell
(called a capsid) around the nucleic acid. Certain viruses also have other
proteins internal to the capsid. Some of these proteins act as enzymes during
the synthesis of viral nucleic acids.
This isn't always the case and there is no reason it should be .Whether or not a trait is common has to do with how many copies of that gene version (or allele) are in the population. It has little or nothing to do with whether the trait is dominant or recessive. Let's take eye color as an example.
Mitosis produces all animal and plant cells
Answer:
Lower esophageal sphincter
Explanation:
The biological valves are the muscular structures composed of the smooth muscles which form thick tubular structure to allow the controlled movement of any material through it. The valves in the digestive system are known as the sphincters.
The sphincters control the unidirectional movement of the eaten food, chyme and the bolus in the digestive tract.
A sphincter is present at the lower portion of the oesophagus (food pipe) which contracts to prevent the backflow of the food from the stomach and since the sphincter is present at the lower side of the oesophagus, therefore, is known as the lower esophagal sphincter.
Thus, Lower esophageal sphincter is correct.