Q.Differentiate between (A) Innate immunity and acquired immunity (B) Primary and secondary immune responses (C) Active and passive immunity (D) Humoral and CMI immunity (E) Autoimmune disease and Immunodeficiency disease

Step 1 — (A) Innate vs acquired immunity. Innate immunity is present from birth, non-specific, and acts against a broad range of pathogens through anatomical, physiological, phagocytic and inflammatory barriers. Acquired immunity develops after birth against a specific pathogen, shows antigenic specificity, diversity and immunological memory, and is carried out by lymphocytes (B and T cells).

Step 2 — (B) Primary vs secondary immune response. The primary response occurs on first contact with an antigen, is slow (antibody peaks in 7–10 days), declines rapidly, and occurs mainly in lymph nodes/spleen. The secondary response occurs on repeat contact with the same antigen, is fast (peaks in 3–5 days) due to memory cells, produces a much higher and longer-lasting antibody level, and occurs mainly in the bone marrow followed by spleen/lymph nodes.

Step 3 — (C) Active vs passive immunity. Active immunity is produced by the host's own immune system in response to infection/immunization, is durable, forms memory, and shows a booster effect, but takes time to develop. Passive immunity involves antibodies received from an external source with no active host participation, is immediate but transient, and forms no memory.

Step 4 — (D) Humoral vs cell-mediated immunity (CMI). Humoral (antibody-mediated) immunity is carried out by B cells (with T-helper cell assistance) producing antibodies that act in body fluids. CMI is carried out directly by T cells, macrophages and natural killer cells destroying pathogens/infected cells without producing antibodies. …

Work through each named pair using its defining criterion (origin, timing, mechanism, or nature of …

• Answering only some of the five sub-parts
• Blurring active/passive with primary/secondary, …