Question 1

The trachea is a tube that carries air from the larynx to which of the following structures?

Accepted Answer

The trachea (windpipe) is a cartilaginous tube that carries air from the larynx (voice box) down to the bronchi, which then branch into the lungs. It is lined with ciliated epithelium that helps trap and remove dust and pathogens.

Question 2

Vitamin D is primarily synthesized in the human body through exposure to which of the following?

Accepted Answer

Vitamin D is synthesized in the skin when exposed to ultraviolet B (UVB) radiation from sunlight. This is why it is often called the 'sunshine vitamin.' The liver and kidneys then convert it to its active form.

Question 3

Which gland in the human body produces insulin?

Accepted Answer

The pancreas is an endocrine gland that produces insulin, a hormone essential for regulating blood glucose levels. Insulin allows cells to absorb glucose from the bloodstream for energy or storage.

Question 4

Which of the following is the largest bone in the human body?

Accepted Answer

The femur (thighbone) is the longest and strongest bone in the human body, extending from the hip to the knee. It bears most of the body's weight during standing and walking.

Question 5

How many chambers does the human heart have?

Accepted Answer

The human heart is a four-chambered organ consisting of two upper chambers (atria) and two lower chambers (ventricles). The right side receives deoxygenated blood; the left side pumps oxygenated blood.

Question 6

Vitamin C deficiency in the human body leads to which disease?

Accepted Answer

Vitamin C (ascorbic acid) is essential for collagen synthesis, immune function, and antioxidant protection. Its deficiency causes scurvy, characterized by bleeding gums, poor wound healing, and weakened connective tissues.

Question 7

Which of the following is the primary function of haemoglobin in the human body?

Accepted Answer

Haemoglobin is an iron-containing protein in red blood cells that binds to oxygen in the lungs and transports it to tissues throughout the body. It also carries carbon dioxide back to the lungs for exhalation.

Question 8

Which vitamin is synthesized by the human body when skin is exposed to sunlight?

Accepted Answer

Vitamin D is synthesized in the skin when exposed to ultraviolet B (UVB) radiation from sunlight. This vitamin is essential for calcium absorption and bone health.

Question 9

Which of the following is the primary function of haemoglobin in the human body?

Accepted Answer

Haemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to tissues and carrying carbon dioxide back to the lungs for exhalation.

Question 10

Which of the following is the correct sequence of blood flow through the human heart?

Accepted Answer

The correct sequence of blood flow is: Deoxygenated blood enters the right atrium → flows to the right ventricle → pumped to the lungs via the pulmonary artery → oxygenated blood returns to the left atrium via the pulmonary veins → flows to the left ventricle → pumped to the body via the aorta.

Question 11

Which of the following is the primary function of hemoglobin in the human body?

Accepted Answer

Hemoglobin is an iron-containing protein found in red blood cells (RBCs) that binds to oxygen in the lungs and transports it to tissues throughout the body. It also carries carbon dioxide back to the lungs for exhalation. This oxygen-transport function is hemoglobin's primary role in maintaining aerobic respiration in all body cells.

Question 12

Which of the following vitamins is essential for blood clotting in the human body?

Accepted Answer

Vitamin K is essential for blood clotting. It is a fat-soluble vitamin that acts as a coenzyme for the synthesis of prothrombin and other clotting factors (II, VII, IX, X) in the liver. Without adequate vitamin K, blood cannot clot properly.

Question 13

Which of the following hormones is produced by the pancreas and regulates blood glucose levels?

Accepted Answer

Insulin is a hormone produced by the beta cells of the islets of Langerhans in the pancreas. It lowers blood glucose levels by facilitating glucose uptake into cells and promoting its storage as glycogen in the liver and muscles.

Question 14

How many chambers does the human heart have?

Accepted Answer

The human heart has four chambers: two upper chambers called atria (right and left) and two lower chambers called ventricles (right and left). The right side pumps deoxygenated blood to the lungs, and the left side pumps oxygenated blood to the body.

Question 15

The process by which the small intestine absorbs digested nutrients into the bloodstream is called:

Accepted Answer

Absorption is the process where digested nutrients (glucose, amino acids, fatty acids, vitamins, minerals) pass through the intestinal epithelium into the blood and lymphatic system. The small intestine, with its villi and microvilli, is the primary site of absorption.

Question 16

The hormone responsible for regulating calcium levels in the blood is secreted by which gland?

Accepted Answer

Parathyroid hormone (PTH) is the primary regulator of blood calcium levels. It is secreted by the parathyroid glands, four small endocrine glands located behind the thyroid gland.

Question 17

Vitamin B12 deficiency primarily leads to which type of anemia?

Accepted Answer

Vitamin B12 is essential for DNA synthesis and red blood cell maturation. Its deficiency results in the production of abnormally large red blood cells, causing megaloblastic anemia.

Question 18

Which of the following is the primary function of the pancreas in the human body?

Accepted Answer

The pancreas has two main functions: it produces digestive enzymes (exocrine function) and regulates blood glucose through insulin and glucagon secretion (endocrine function). Both functions are equally important, but the question tests knowledge of its dual role.

Question 19

Which of the following blood cells is responsible for carrying oxygen throughout the body?

Accepted Answer

Red blood cells (erythrocytes) contain hemoglobin, an iron-containing protein that binds oxygen in the lungs and releases it in tissues. They are the primary oxygen carriers in blood.

Question 20

The filtration of blood to form urine primarily occurs in which part of the kidney?

Accepted Answer

The nephron is the functional unit of the kidney. Ultrafiltration (first stage of urine formation) occurs in the Bowman's capsule and glomerulus, where small molecules like glucose, urea, and water are filtered from blood into the capsule.

NDA Biology — Human Body

Biology — Human Body — Practice Questions