IMMUNOLOGY

Detailed explanation-1: -Antibodies are proteins made by the body’s natural defence system (immune system) to fight foreign substances, such as bacteria. Antibodies attach themselves to the foreign substance, allowing other immune system cells to attack and destroy the substance.

Detailed explanation-2: -Antibodies act against viruses primarily by binding to and neutralizing virions and by directing the lysis of infected cells by complement or killer leukocytes.

Detailed explanation-3: -1) Antibodies are secreted into the blood and mucosa, where they bind to and inactivate foreign substances such as pathogens and toxins (neutralization). 2) Antibodies activate the complement system to destroy bacterial cells by lysis (punching holes in the cell wall).

Detailed explanation-4: -Antibodies are Y-shaped proteins produced as part of the body’s immune response to infection. They help eliminate disease-causing microbes from the body, for instance by directly destroying them or by blocking them from infecting … cells.