IMMUNOLOGY

Detailed explanation-1: -They do this by recognising substances called antigens on the surface of the microbe, or in the chemicals they produce, which mark the microbe or toxin as being foreign. The antibodies then mark these antigens for destruction. There are many cells, proteins and chemicals involved in this attack.

Detailed explanation-2: -If an antigen enters the body and B-cells recognize it (either from having had the disease before or from being vaccinated against it), B-cells will produce antibodies. When antibodies attach to an antigen (think a lock–key configuration), it signals other parts of the immune system to attack and destroy the invaders.

Detailed explanation-3: -Antigens are proteins that are found on the surface of the pathogen. Antigens are unique to that pathogen. The whooping cough bacterium, for example, will have different antigens on its surface from the TB bacterium. When an antigen enters the body, the immune system produces antibodies against it.

Detailed explanation-4: -Pathogens have molecules called antigens on their surface. Antigens provide a unique signature for the pathogen that enables immune system cells to recognize different pathogens and distinguish pathogens from the body’s own cells and tissues.

Detailed explanation-5: -Antibodies attach themselves to the foreign substance, allowing other immune system cells to attack and destroy the substance. The surfaces of viruses, fungi, and bacteria contain markers called antigens.

Detailed explanation-6: -An inflammatory response begins when a pathogen stimulates an increase in blood flow to the infected area. Blood vessels in that area expand, and white blood cells leak from the vessels to invade the infected tissue. These white blood cells, called phagocytes engulf and destroy bacteria.