$MALT$ constitutes about ................. of the lymphoid tissue in the human body. (in $\%$)

The treatment of snake-bite by antivenom is an example of

Read the given statements carefully and identify the incorrect statements.
$(1)$ In active acquired immunity,antibodies are directly injected into the body.
$(2)$ Vaccination is considered under passive acquired immunity.
$(3)$ The human body distinguishes between self and non-self with the help of $Tc$ cells.
$(4)$ Innate immunity consists of four types of barriers.

Who is known as the father of immunology?

What is produced in innate immunity to prevent the entry of foreign agents into the body?

$A$ person who met with a road accident is likely to develop tetanus. He is immunized by administering: