Which of the following statements are correct?

I. The exaggerated response of the immunesystem to certain antigens present in the environment is called allergy.

II. The allergic tendency is genetically passed from the parents to the offspring and is characterised by the presence of large quantities of IgG antibodies in the blood.

III. Bone marrow and thymus are the organs where origin and/or maturation and proliferation of ymphocytes occur.

IV. Immunisation is the process by which the body produces antibodies against the vaccine preventable diseases through administration of specific vaccines.