‘Maintenance of personal and public hygiene is necessary for prevention and control of many infectious diseases’. Justify the statement giving suitable examples.

OR

(a) What does the term ‘memory of the immune system’ mean?

(b) Name the types of acquired immune responses and the special types of lymphocytes involved in providing them.

Preventive measures should be taken for prevention and control of such diseases, maintenance of personal and public hygiene are as follows:
(i) Education.
(ii) Isolation
(iii) Vaccination
(iv) Sanitation
(v) Eradication of Vectors
(vi) Sterilisation

OR

(a) Memory of the immune system produces an intensive secondary response when the pathogen attacks the second time.

(b) Types of acquired immune responses are

(i) Humoral immune response provided by B-lymphocytes.

(ii) Cell-mediated immune response provided by T-lymphocytes.