Explanation

• The kidneys purify the blood in the human body.
• They remove waste materials and extra water.
• Kidneys help maintain the body’s chemical balance.
• Each person has two kidneys.
• They produce urine as a waste product.

Last verified on 07-06-2026

Explanation

• The Doppler Effect is the change in the observed frequency of sound due to the relative motion between the source and the observer.
• If the source and observer move toward each other, the observed frequency increases.
• If they move away from each other, the observed frequency decreases.
• A common example is the changing pitch of an ambulance siren as it passes by.

Last verified on 02-09-2026

Explanation

• Alexander Graham Bell is credited as the inventor of the telephone.
• He was awarded the first successful patent for it.
• The telephone was invented in 1876.
• Bell made the first-ever telephone call to his assistant Thomas Watson.

Last verified on 31-03-2026

Explanation

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