Interferons are synthesized in response to which of the following?

Snake venom antibody, which is prepared against snake venom, is an example of which type of immunization?

What is an anamnestic response?

Select the correct pair:

Column-$I$	Column-$II$
$A$. Physiological barrier	$1$. Skin
$B$. Cellular barrier	$2$. Macrophages
$C$. Physical barriers	$3$. Interferons
$D$. Cytokine barriers	$4$. Tears
	$5$. Mucus

Match the type of immunity listed in Column-$I$ with the examples listed in Column-$II$. Choose the answer that gives the correct combination of alphabets of the two columns:

Column-$I$ (Types of immunity)	Column-$II$ (Example)
$A$. Natural active	$p$. Immunity developed by heredity
$B$. Artificial passive	$q$. From mother to foetus through placenta
$C$. Artificial active	$r$. Injection of antiserum to travellers
$D$. Natural passive	$s$. Fighting infections naturally
	$t$. Induced by vaccination

Match the following columns:

Column-$I$	Column-$II$
$P$. Physical barriers	$I$. Acid in stomach,saliva in mouth,tears from eyes
$Q$. Physiological barriers	$II$. Skin,mucus coating of epithelium lining the respiratory,gastrointestinal and urogenital tracts
$R$. Cellular barriers	$III$. Interferons
$S$. Cytokine barriers	$IV$. Polymorphonuclear leukocytes ($PMNL$-neutrophils),monocytes,$NK$ cells,macrophages