A condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue is called

Antigen binding site in an antibody is found between

What is the basic principle of vaccination ? How do vaccines prevent microbial infections ? Name the organism from which hepatitis $B$ Vaccine is produced.

$T$- Lymphocytes originate from

Draw and describe the structure of antibody?

Choose the true statements

$I.$ Innate immunity is accomplished by providing different types of barriers

$II.$ Acquired immunity is present from the birth and is inherited from parents

$III.$ Sweat, tears, acid in the stomach and saliva prevent microbial growth