$B$-cells are lymphocytes which produce the humoral immunity. These cells are produced by

Many microbial pathogens enter the gut of humans along with food. What are the preventive barriers to protect the body from such pathogens ? What type of  immunity do you observe in this case ?

Consider the following statements

$I.$ People should get vaccination to avoid infection

$II.$ Vaccination is available against polio, cholera, typhoid, tuberculosis and many othe disease

$III.$ Eradication of vectors are necessary in diseases like malaria and filariasis

$IV. $ Dengue and chikengunya, both are spread by Culex mosquitoes

Which of the statements given above are correct?

When an organ is transplanted and is rejected by the body, the lymphocytes are produced by

The yellowish fluid "colostrum" secreted by mammary glands of mother during the initial days of lactation has abundant antibodies ($lgA$) to protect the infant. This type of immunity is called as 

What is interferon