The skin and mucous membrane act as which type of barrier in innate immunity?

In case of snakebites,the injection given to patients contains preformed antibodies against the snake venom. This type of immunisation is called . . . . . . .

Which type of immunity is characterized by memory?

Arrange the steps of the $phagocytosis$ process in the correct sequence.
$(a)$ Ingestion of microbes by phagocytes
$(b)$ Dilation of blood vessels by histamine
$(c)$ Formation of $phagosome$ and $phagolysosome$
$(d)$ Migration of phagocytes into $E.C.F.$
$(e)$ Attraction of phagocytes by $chemotoxins$ secreted by microbes
$(f)$ Intracellular destruction of bacteria

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

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: