How many peptide chains are present in the structure of an antibody?

What are the characteristics of acquired immunity?

Choose the true statements.
$I.$ Innate immunity is accomplished by providing different types of barriers.
$II.$ Acquired immunity is present from birth and is inherited from parents.
$III.$ Sweat,tears,acid in the stomach,and saliva prevent microbial growth.

Innate immunity is defined as.........

$T$-cells mature in the . . . . . . .

Memory cells are responsible for: