Explanation

• Edward Jenner was an English physician and scientist.
• He discovered the first vaccine for smallpox in 1796.
• He observed that milkmaids infected with cowpox were protected from smallpox.
• This led to the development of vaccination (cowpox-based immunity method).
• He is known as the Father of Immunology.

Last verified on 02-05-2026

Explanation

• Jabir ibn Hayyan, known as the "father of chemistry."
• He was an Arab Chemist.
• Composition of Alchemy was written by Jabir Bin Hayyan.

Notable ideas:

• Use of organic substances in chemistry
• Sulfur-mercury theory of metals
• Science of the balance
• Science of artificial generation

Last verified on 07-02-2026

Explanation

• Polio Vaccines: Developed to prevent poliomyelitis, a viral disease causing paralysis.
• Jonas Salk (US, 1950s): Created the first inactivated (killed) polio vaccine; tested on himself and family in 1953; officially used in 1955.
• Albert Sabin (1961): Developed the live attenuated (weakened) oral polio vaccine.
• Recent Campaigns: Israel launched a polio vaccine drive in April 2022 after 1988 efforts.

Last verified on 03-04-2026

Explanation

• A lactometer is used to measure the purity and density (thickness) of milk.
• It checks if milk has been adulterated with water by measuring specific gravity.
• Works on the principle of buoyancy.
• Pure milk specific gravity: 1.028–1.032 at 15°C

Last verified on 16-03-2026

Explanation

• Isaac Newton (1642–1727) was an English physicist and mathematician.
• He formulated the laws of motion and law of universal gravitation.
• His work laid the foundation for classical mechanics.

Last verified on 02-04-2026