Vaccination & Immunisation - NEET Biology Class 12 Free MCQ Test with solutions

Innate immunity is non-specific and relies on barriers. If a pathogen bypasses these, innate immunity fails.

NK cells are part of innate immunity and destroy infected cells quickly before specific immunity is activated.

Memory cells lead to a rapid, stronger secondary response.

IgM is produced first in primary immune responses and indicates recent infection.

Injected antibodies act immediately and do not produce memory; vaccines induce active immunity.

Interferons are antiviral, mast cells release histamine, Peyer’s patches are intestinal lymphoid tissues, and thymus matures T-cells.

Thymus governs T-cell maturation; degeneration reduces T-cell mediated immunity.

Humoral immunity involves antibody production by plasma cells.

Allergy reactions involve IgE binding to mast cells, which release histamine.

Autoimmunity results from self-reactive lymphocytes attacking body tissues.

Rapid and intense response is characteristic of secondary exposure.

The spleen filters blood and traps pathogens.

MALT is present in mucosal linings of respiratory, digestive and urogenital tracts.

Answer: C

Innate immunity does not produce a stronger or faster response on subsequent exposures because it lacks immunological memory, so lack of memory is the distinguishing feature.

Innate responses are non-specific and act immediately, whereas acquired (adaptive) immunity is specific to particular pathogens and develops memory after exposure.

The option Presence of antibodies is a feature of adaptive immunity (antibodies are produced by B cells), so it does not describe innate immunity.

The option Involvement of T-cells refers to adaptive cellular responses; T-cells are components of adaptive immunity, not a defining feature of innate immunity.

Therefore, only option C correctly identifies a feature that distinguishes innate immunity from acquired immunity.

Cell-mediated immunity (T-cells) recognises non-self tissues and initiates graft rejection.