Answer:
<u>Antigenic drift</u> refers to the slow accumulation of genetic changes to an influenza virus over time.
Explanation:
Antigenic drift is defined as the mechanism by which viruses undergo variation. This mechanism involves the slow accumulation of mutations in the viral genes, that are responsible for coding the antibody binding sites. This leads to the formation of a new strain of virus, which can't be inhibited by the old antibodies. Due to this, the virus can easily spread the disease.
The antigenic drift occurs in the influenza A virus and also the influenza B viruses.
Therefore, <u>Antigenic drift refers to the slow accumulation of genetic changes to an influenza virus over time.</u>
Answer:
Myelin sheath increases the speed of electrical impulse along the nerve cells.
Explanation:
Myelin sheath is an insulting layer of proteins and fatty acids that are present around the nerves of brain and spinal cord.
Myelin sheath increases the speed of conduction of nerve impulse from one nerve cell to another cell. Myelin sheath is formed by the concentric wrapping of schwann cells around the axon. This sheath decreases axonal membrane capacitance and increases the conduction of nerve impulse.
Answer:
either the first one lactic acid fermentation or the third one alcoholic fermentation