Aids to Health

ICSE Class 10 Biology • Chapter 12

1. Immunity

Immunity: The ability of the body to resist diseases caused by pathogens (germs) and their toxic products.

Types of Immunity:

Innate (Natural) Immunity: Present from birth (e.g., Skin, tears, WBCs).
Acquired (Adaptive) Immunity: Developed during lifetime.
- Active Acquired: Body produces its own antibodies (e.g., after recovering from Chickenpox or Vaccination).
- Passive Acquired: Ready-made antibodies received (e.g., Maternal antibodies via placenta/milk, Anti-venom serum).

Practice Q1: Immunity Types

CONCEPT CHECK Which type of immunity is acquired after an infection like Chickenpox?

Ans: Active Acquired Immunity (as the body produces its own antibodies).

2. Vaccination (Immunisation)

The practice of artificially introducing germs (killed or weakened) into the body to stimulate immunity.

Jenner's Cowpox Experiment: Edward Jenner used cowpox virus to immunise against smallpox.

3. Antiseptics and Disinfectants

Antiseptic	Disinfectant
Mild chemical. Applied on Living Tissues (Skin).	Strong chemical. Applied on Non-living objects (Floors, instruments).
Example: Boric Acid, Dettol.	Example: Cresol, Bleaching Powder.

4. Antibiotics

Antibiotics: Chemical substances produced by microorganisms (bacteria/fungi) that kill or inhibit the growth of other harmful microorganisms.

Example: Penicillin (from fungus Penicillium notatum) discovered by Alexander Fleming.

Practice Q2: Antibiotics

BOARD QUESTION Who discovered Penicillin?

Ans: Alexander Fleming (from the mould Penicillium notatum).

5. First Aid

Meaning: The immediate care given to a victim of an accident or sudden illness before medical help arrives.

Burns: Wash with cold water. apply antiseptic.
Bleeding: Press firmly with clean cloth. Elevate limb.
Fracture: Do not move the part. Use splint.
Snake Bite: Tie a tourniquet above bite. Keep patient calm.

6. Health Organisations

Red Cross

International body for humanitarian aid during war and peace.

First Aid training.
Blood banks.
Disaster relief.

WHO (World Health Organization)

Agency of UN. HQ: Geneva.

Eradication of diseases (Smallpox, Polio).
Promoting maternal and child health.
Setting drug standards.

Exam Practice Questions

Practice Q3: First Aid

APPLICATION What is the immediate first aid for a chemical burn?

Ans: Wash with plenty of running water to dilute and remove the chemical.

Q1: Differentiate between Antigen and Antibody.

Ans: Antigen is a foreign substance (germ/protein) that stimulates the body to produce specific chemical substances. Antibody is the protein produced by WBCs (Lymphocytes) to fight against a specific antigen.