What does $T$ stand for in $T$-lymphocytes?

An antiviral chemical produced by the animal cell is

Where do immature lymphocytes differentiate into antigen-sensitive lymphocytes?

What is the immunity that an individual inherits from birth called?

The yellowish fluid "colostrum" secreted by mammary glands of the mother during the initial days of lactation has abundant antibodies $(IgA)$ to protect the infant. This type of immunity is called:

Match the following columns correctly:

Column-$I$	Column-$II$
$(a)$ Physical barrier	$(w)$ Saliva
$(b)$ Physiological barrier	$(x)$ Interferons
$(c)$ Cellular barrier	$(y)$ Skin
$(d)$ Cytokine barrier	$(z)$ Monocytes