Explanation

• DNA stands for Deoxyribonucleic Acid.
• DNA is a biological molecule found in all living cells.
• It carries genetic information from parents to offspring.
• It controls growth, development, and body functions.
• DNA is present in the nucleus of cells (mainly in chromosomes).
• It is made of nucleotides arranged in a double helix structure.
• It was discovered by James Watson and Francis Crick (1953 structure model).

Last verified on 01-06-2026

Explanation

• Main Cause: Freon / CFCs
• Effect: Breaks down O₃ molecules → more UV-B radiation
• Other Contributors: Halons, carbon tetrachloride
• Result: Skin cancer, cataracts, climate impact

• The Montreal Protocol (1987) aimed to reduce CFC emissions
• Ozone layer protects Earth from harmful ultraviolet rays

Explanation

• Liver produces bile, which helps in digestion of fats in the human body.
• Bile is a digestive fluid essential for fat breakdown.
• It is produced continuously by the liver.
• It is stored and concentrated in the gallbladder.
• It is released into the small intestine during digestion.

Last verified on 08-06-2026

Explanation

• The cornea is the transparent, curved outer layer at the front of the eye.
• It helps focus light entering the eye.
• It protects the iris, pupil, and other internal parts of the eye.
• The cornea does not contain blood vessels but has many nerve endings.

Last verified on 02-09-2026

Explanation

• The kidney was the first human organ to be successfully transplanted.
• The first successful living-donor kidney transplant was performed on December 23, 1954.
• It was performed by Dr. Joseph Murray and his team in Boston, USA.
• The transplant was between identical twins, Ronald and Richard Herrick.

Last verified on 02-09-2026

Explanation

• A normal human body has one gallbladder.
• The gallbladder is a small, pear-shaped organ located beneath the liver.
• It stores and concentrates bile, which helps digest fats.
• Bile is released into the small intestine during digestion.

Last verified on 02-09-2026

Explanation

• The term “antigen” was coined in 1899 by Ladislas Deutsch (László Detre).
• The word is derived from “antibody-generating” (anti + gen).

Additional information:

• Louis Pasteur is famous for his work on vaccination and germ theory.
• Edward Jenner pioneered the smallpox vaccine.

Last verified on 01-09-2026

Explanation

• The skin is considered the largest organ of the human body.
• It covering an area of about 1.5-2 square meters (16-22 square feet).
• It weighing around 3-4 kilograms (7-9 pounds).

Last verified on 01-09-2026

Explanation

• Phosphorus is not among the top 10 most abundant elements in the Earth's crust.
• Most abundant element in Earth crust is Oxygen.
• Oxygen in the crust is (46. 1%).
• The chemical formula of oxygen (dioxygen) is O2.

List of 10 Most Abundant Elements in the Earth's Crust:

Last verified on 01-09-2026

Explanation

• Deuteranopia is a type of red-green colour blindness caused by the absence of functioning green-sensitive cones.
• It mainly affects the ability to distinguish green from red.
• It is an X-linked recessive condition.
• It is more common in males.

Last verified on 01-09-2026