Perforin is secreted by which of the following cells to prevent the effect of microbes?

Lymph nodes form:

Give scientific reasons: Virus-infected cells provide innate immunity to other cells.

$A$ - Colostrum contains several antibodies.
$R$ - Due to colostrum,immunity is decreased in the child.

Which of the following can be used to provide immunity to a person who is at risk of developing tetanus?

After maturation,in primary lymphoid organs,the lymphocytes migrate for interaction with antigens to secondary lymphoid organs like:
$A.$ thymus $B.$ bone marrow $C.$ spleen $D.$ lymph nodes $E.$ Peyer's patches
Choose the correct answer from the options given below: