Question

Read the following passage and answer the questions that follow :

Immunity in our body is of two types (i) Innate immunity, and (ii) Acquired immunity. Innate immunity is a non-specific defence mechanism, whereas Acquired immunity is pathogen specific. Acquired immunity is characterised by memory. Antibodies are specific to antigens and there are four types of antibodies produced in our body - IgA, IgE, IgG and IgM. It shows primary response where it encounters the pathogen for the first time and secondary response during the subsequent encounters with the same antigen/pathogen. These immune responses are carried out with the help of two special types of lymphocytes present in the blood.

How is active immunity different from passive immunity ? Write any two differences.

Hint:

Compare who makes the antibodies and how long the protection lasts.

Answer 1

Step 1: Define both types:
Active immunity is built when the host's own immune system makes antibodies after meeting an antigen (infection or vaccine).
Passive immunity is given when ready-made antibodies are passed to the body from outside, for example from the mother or by an injection.

Step 2: Compare them point by point:
1. Source of antibodies: in active immunity the host's own B-cells make them. In passive immunity they are received ready-made.
2. Speed and time: active immunity is slow to start, as the body needs time to respond, but it lasts long and has memory. Passive immunity acts quickly but lasts a short time and has no memory.
3. Example: a vaccine or natural infection gives active immunity. Colostrum (the first milk, rich in IgA) or an antivenom injection gives passive immunity.

Final Answer:
Any two differences as above, for example antibodies made by self versus received ready-made, and slow but long-lasting versus quick but short-lived.