Question

PMNL are____(i)____barriers that provide__(ii)____immunity.

• A. (i)-cytokine, (ii)-acquired
• B. (i)-cellular, (ii)-acquired
• C. (i)-cytokine, (ii)-innate
• D. (i)-cellular, (ii)-innate

Answer 1

The correct option is D (i)-cellular, (ii)-innate

Immunity is the ability of the host to fight against infections. It is the function of the immune system in the body.

Immunity in higher vertebrates is of two types, innate immunity and acquired immunity.

Innate immunity is present since birth and is non-specific. It provides protection against various pathogens. It includes physical, physiological, cellular and cytokine barriers.

PMNL are cellular barriers that provide innate immunity. PMNL refers to polymorpho-nuclear leukocytes (PMNL-neutrophils). These are a type of WBCs that can phagocytose and destroy microbes.

On the other hand, cytokine barriers include proteins like interferons. Interferons are proteins secreted by the virus-infected cells in order to protect the non-infected cells from further viral infection.

Acquired immunity is specific. It is acquired during the life time as the person gets exposed to various pathogens.