Explain the roles of (1) primary, and (ii) secondary lymphoid organs that are responsible for developing defence to combat the action of pathogens/foreign antigens which enter our body.

Lymph nodes are secondary lymphoid organs. Explain the role of lymph nodes in our immune response.

(i) Name the organism in which the vector shown in inserted to get the copies of the desired gene. (ii) Mention the area labelled in the vector responsible for controlling the copy number of the inserted gene. (iii) Name and explain the role of a selectable marker in the vector shown.

(a) Name the three major classes of carbohydrates and give an example of each of these classes. (b) Ans the following : (i) What type of linkage is responsible for the primary structure of proteins ? (ii) Name the location where position synthesis occurs in our body. OR (a) How are lipids classified ? Given an example of each class. (b) Explain the following terms : (i) Mutarotation (ii) Avitaminosis.

The modern idea about ageing is that our body slowly loses the power of defence against the invasion of germs and pathogens. This proces starts by the disappearance of which organ?

A type of granulocyte and agranulocyte (i) are phagocytic cells that destroy foreign organisms entering the body. (ii) secrete histamine, serotonin, heparin, etc., and are involved in inflammatory reactions. (iii) resist infections and are also associated with allergic reactions. (iv) are responsible for the immune responses of the body.