Question

(a) Differentiate between humoral immune response and cell-mediated immune response.
(b) Draw a schematic diagram of an antibody molecule and label any four parts.

Hint:

(a) Humoral immunity is antibody-based and targets pathogens in bodily fluids, while cell-mediated immunity involves T cells attacking infected or cancerous cells directly.
(b) The antibody’s variable region binds to antigens, and its constant region helps in immune cell recognition and activation.

Answer 1

(a) - Humoral Immunity: B cells produce antibodies that neutralize pathogens and prevent infections. This process is primarily achieved through antibodies in bodily fluids.
- Cell-mediated Immunity: T cells, especially cytotoxic T cells, execute this response by targeting and eliminating infected or cancerous cells. Antibodies are not involved.
(b)

- An antibody possesses a "Y" shape, comprising two heavy chains and two light chains.
- Variable Region: Situated at the Y's extremities, it is responsible for antigen binding.
- Constant Region: Forming the Y's stem, it dictates the antibody class (e.g., IgG, IgM).
- Hinge Region: Positioned between the Y's arms, it provides flexibility.
- Disulfide Bonds: These bonds link the heavy and light chains.