Free Human Body and Health MCQs with Answers

51. Which of the following have maximum calorific value?

• A. Carbohydrates
• B. Fats
• C. Proteins
• D. Vitamins

Explanation: Fats provide about 9 kilocalories per gram, whereas carbohydrates and proteins provide about 4 kilocalories per gram. Vitamins are regulatory nutrients and do not supply significant calories.

52. Which gland in the human body is called the master gland?

• A. Pancreas
• B. Thyroid
• C. Pituitary
• D. Spleen

Explanation: The pituitary is called the master gland because its hormones regulate several other endocrine glands, including the thyroid, adrenal glands, and reproductive glands. The hypothalamus controls the pituitary.

53. How many bones are there in a newly born infant?

• A. 206
• B. 230
• C. 280
• D. 300Purchasing Educational Biology Kits

Explanation: A newborn is commonly said to have about 300 bones, many of which later fuse as the skeleton develops. This number is approximate, while the standard adult count is 206.

54. Which is the largest gland in the human body?

• A. Thyroid
• B. Liver
• C. Pancreas
• D. None of these

Explanation: The liver is the largest gland in the human body and performs metabolic, detoxification, storage, and bile-producing functions. The thyroid is a major endocrine gland but is much smaller.

55. A person of which of the following blood groups is called a universal donor?

• A. O
• B. AB
• C. A
• D. B

Explanation: O-negative red blood cells are traditionally called universal donor blood because they lack A, B, and RhD antigens. In the simplified ABO classification used here, the answer is O.

56. Which of the following glands secrete tears?

• A. Lachrymal
• B. Pituitary
• C. Thyroid
• D. Pancreas

Explanation: Lacrimal, or lachrymal, glands produce tears that lubricate and protect the eye. The pituitary, thyroid, and pancreas are endocrine or digestive glands with different functions.

57. The function of hemoglobin is____________?

• A. Transportation of oxygen
• B. Destruction of bacteria
• C. Prevention of anemia
• D. Utilization of energy

Explanation: Hemoglobin is the iron-containing protein in red blood cells that binds oxygen in the lungs and carries it to body tissues. It also carries a portion of carbon dioxide back toward the lungs.

58. The main function of the kidney is ____________?

• A. To control blood pressure
• B. To control body temperature
• C. To remove waste product from the body
• D. To help in digestion of food

Explanation: Kidneys filter the blood and remove nitrogenous wastes, excess water, and salts to form urine. They also help regulate blood pressure and fluid balance, but waste removal is their main listed function.

59. The main constituent of hemoglobin is___________?

• A. Chlorine
• B. Iron
• C. Calcium
• D. None of these

Explanation: Iron is the key mineral in hemoglobin's heme group, where it binds oxygen reversibly. Chlorine and calcium have important body roles but are not the main constituent of hemoglobin.

60. What is the main component of bones and teeth?

• A. Calcium carbonate
• B. Calcium phosphate
• C. Calcium sulphate
• D. Calcium nitrate

Explanation: The hard mineral portion of bones and teeth is mainly hydroxyapatite, a calcium phosphate compound. Calcium carbonate and the other listed salts are not the principal structural mineral.