Human Health & Disease Test - 1

Broad-spectrum antibiotics are those that act against a wide range of disease-causing bacteria both Gram-positive and Gram-negative, in contrast to a narrow-spectrum antibiotic, which is effective against specific families of bacteria.

Hay fever is an allergy caused by pollen or dust in which the mucous membranes of the eyes and nose are inflamed, causing running at the nose and watery eyes.

Three main events occur in the process of formation of antigen-antibody complex. These are – agglutination, opsonization and neutralization. 

(i) Agglutination : When an antibody comes in contact with the antigen, foreign bodies like virus, bacteria etc. It becomes associated with them and are converted into a mass of harmless, insoluble matter. 

(ii) Opsonization : Specific immunoglobulin molecules, surround the antigen over its surface. The phagocytes identify such complexes, engulf them and destroy them. 

(iii) Neutralization : Antibodies make the toxins produced by viruses and bacteria ineffective and destroy them.

Acquired immunity is obtained during the life of an individual to a particular micro-organism due to previous infection, vaccination or inoculation of antiserum. It has four unique

characteristics : 

(i) Specificity : It is specific for each & every type of pathogen. 

(ii) Diversity : It operates against the whole diversity of pathogenic organisms, their toxins & pollutants. 

(iii) Difference between self & non-self : It can differentiate molecules & cells of foreign origin from those of self. 

(iv) Memory : The immunity against a pathogen developed during an initial infection is retained by the individual so that second encounter with the pathogen invites a heightened immune response.

Lysozyme is an antibacterial enzyme widely distributed in body fluids & secretions including tears & saliva. It disrupts the polysaccharide components of bacterial cell walls, leaving them susceptible to destruction.

Immunoglobulin M (IgM) is a basic antibody that is produced by B-cells. It has a molecular mass of approximately 970 kDa (in its pentamer form).

Artificially acquired passive immunity is a short-term immunization by the injection of antibodies, such as gamma globulin, that are not produced by the recipient’s cells.

SCID is a group of inherited disorders that cause severe abnormalities of the immune system. These disorders lead to reduced or malfunctioning T- and B-lymphocytes, the specialized white blood cells made in the bone marrow and the thymus gland to fight infection.