$A$ molecule that elicits an immune response is called

Introduction of attenuated pathogens in human body results in . . . . . . .

Along with lymphoid organs,$WBCs$ are also present within the mucosa of digestive,respiratory,and excretory tracts as $MALT$,which constitutes about $.......$ of the total lymphoid tissue of the body: (in $\%$)

Lysozyme present in perspiration,saliva,and tears,destroys:

Identify the correct statements from the following:
$(i)$ The skin is the main physical barrier.
$(ii)$ Mucus coating of the epithelium lining the respiratory,gastrointestinal,and urogenital tracts is a physiological barrier.
$(iii)$ $IgA, IgM, IgE, IgG$ are types of $T$-cells.
$(iv)$ The primary immune response is very intense.

Interferons are: