Question

1. Type I hypersensitivity reactions to an allergen only occur in people who have been sensitised to that allergen. This sensitisation involves:

Select one:

a. IgE antibodies to the allergen attaching to mast cells and basophils.

b. the degranulation of mast cells and basophils resulting in the release of histamine and/or other chemical mediators.

c. the allergen attaching to mast cells and basophils.

d. the production of IgE antibodies by mast cells and basophils.

2. Match the class of immunoglobulin with the correct description of that immunoglobulin

a. A pentamer, causes agglutination and lysis of microbes.	1.IgE
b. Located on mast cells and basophils, involved in allergic responses.	2. IgG
c. The most common class of immunoglobulin found in serum, comprising around 80% of all antibodies in the blood.	3. IgA
d. found on the surface of B cells, acts as a cellular receptor.	4. IgD
e. Antibody found in body secretions; including breast milk, mucous and gastrointestinal secretions.	5. IgM

Answer 1

Answer:1 - a) IgE antibodies to the allergen attaching to mast cells and basophils.

Explanation:

Basically Hypersensitivity means that the body responds to a particular substance(also called as allergens) in an overemphasize process where is does not happen in normal conditions or circumstances.

There are four type of hypersenstivity reactions named- type I, type II , type III, type IV.

Type I hypersenstivity reaction: In this B- cells are stimulated by CD4 + TH2 cells for production of IgE antibodies which are specific to antigen.

The differnce between the normal infectious immune response and type I hypersensitivity response is that in type I hpersensitivity the antibody is IgE instead of IgG, IgM. During sensitization the IgE antibodies bind with FC episilon RI receptors on the surface of the mast cell tissues and blood basophils. Mast cells and basophils are coated by IgE antibodies are sensitized.

Answer 2: a- IgD

b -IgE

c- IgG

d - IgM

e - IgA