Practice MCQs

Explanation: Insulin is produced by the beta cells in the islets of Langerhans within the pancreas. Insulin regulates blood glucose levels.

Explanation: A normal human somatic (body) cell contains 46 chromosomes arranged in 23 pairs. Reproductive cells (eggs and sperm) contain 23 chromosomes each.

Explanation: Photosynthesis primarily produces glucose (C6H12O6) using CO2, water and sunlight. Oxygen is released as a by-product.

Explanation: O negative (O-) is the universal donor for red blood cells because it lacks A, B and Rh antigens, making it compatible with all blood types.

Explanation: A gene is the basic unit of heredity. Genes are segments of DNA that encode proteins and are passed from parents to offspring, determining traits.

Explanation: The chemical symbol for gold is Au, derived from the Latin word aurum. Gold's atomic number is 79.

Explanation: Aluminium is the most abundant metal in Earth's crust, making up about 8% of its total mass. It is found mainly as bauxite ore.

Explanation: Common salt (sodium chloride) has the chemical formula NaCl, consisting of one sodium (Na) and one chlorine (Cl) atom held together by an ionic bond.

Explanation: Pure water has a pH of 7, which is neutral. pH below 7 is acidic and above 7 is basic/alkaline.

Explanation: Hydrogen has atomic number 1, meaning it has one proton. It is the lightest and most abundant element in the universe.