Which cells are responsible for the production of antibodies?

Draw and describe the structure of an antibody.

Innate immunity is defined as.........

Which of the following provides the microenvironment for the maturation of $T$-lymphocytes?

Match List-$I$ with List-$II$ :

List-$I$	List-$II$
$a$. Cellular barrier	$i$. Interferons
$b$. Cytokine barrier	$ii$. Mucus
$c$. Physical barrier	$iii$. Neutrophils
$d$. Physiological barrier	$iv$. $HCl$ in gastric juice

Choose the correct answer from the options given below:

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.