In the case of a snakebite, the patient is injected with preformed antibodies against the snake venom. This type of immunity is called.........

The cells which directly attack and destroy the antigens are known as

Which of the following secretes interferons?

What percentage of lymphoid tissue in the human body is constituted by Mucosa-Associated Lymphoid Tissue $(MALT)$ (in $\%$)?

The antibodies are produced by the

Given below are two statements:
Statement $I$: Bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced.
Statement $II$: Both bone marrow and thymus provide micro-environments for the development and maturation of $T$-lymphocytes.
In the light of the above statements,choose the most appropriate answer from the options given below: