MCQ on Digestive System
1. The digestion of carbohydrates begins in the:
(A) Stomach
(B) Mouth
(C) Small intestine
(D) Large intestine
Answer: (B) Mouth
Explanation: Salivary amylase begins the digestion of starch in the mouth.
2. Which enzyme in saliva helps digest starch?
(A) Pepsin
(B) Trypsin
(C) Amylase
(D) Lipase
Answer: (C) Amylase
3. Most digestion and absorption of nutrients occur in the:
(A) Stomach
(B) Small intestine
(C) Large intestine
(D) Oesophagus
Answer: (B) Small intestine
4. Bile is produced by the:
(A) Pancreas
(B) Liver
(C) Gallbladder
(D) Stomach
Answer: (B) Liver
Explanation: The liver produces bile, which is stored and concentrated in the gallbladder.
5. The main function of bile in digestion is to:
(A) Digest proteins
(B) Emulsify fats
(C) Digest carbohydrates
(D) Absorb glucose
Answer: (B) Emulsify fats
Respiratory System
6. The primary organs of respiration in humans are:
(A) Kidneys
(B) Lungs
(C) Liver
(D) Heart
Answer: (B) Lungs
7. Gas exchange between air and blood occurs mainly in the:
(A) Trachea
(B) Bronchi
(C) Alveoli
(D) Larynx
Answer: (C) Alveoli
8. Which gas is transported from the lungs to body tissues mainly by haemoglobin?
(A) Carbon dioxide
(B) Oxygen
(C) Nitrogen
(D) Hydrogen
Answer: (B) Oxygen
9. The muscular structure primarily responsible for breathing is the:
(A) Diaphragm
(B) Biceps
(C) Triceps
(D) Deltoid
Answer: (A) Diaphragm
Circulatory System
10. The human heart has:
(A) Two chambers
(B) Three chambers
(C) Four chambers
(D) Five chambers
Answer: (C) Four chambers
11. Which blood vessel carries oxygenated blood from the lungs to the heart?
(A) Pulmonary artery
(B) Pulmonary vein
(C) Aorta
(D) Vena cava
Answer: (B) Pulmonary vein
12. Which artery carries deoxygenated blood?
(A) Aorta
(B) Pulmonary artery
(C) Coronary artery
(D) Renal artery
Answer: (B) Pulmonary artery
Explanation: The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
13. The largest artery in the human body is:
(A) Pulmonary artery
(B) Aorta
(C) Carotid artery
(D) Renal artery
Answer: (B) Aorta
14. Which blood cells are primarily responsible for transporting oxygen?
(A) White blood cells
(B) Red blood cells
(C) Platelets
(D) Plasma cells
Answer: (B) Red blood cells
15. Which component of blood is mainly responsible for clotting?
(A) RBCs
(B) WBCs
(C) Platelets
(D) Plasma
Answer: (C) Platelets
16. White blood cells primarily help the body to:
(A) Transport oxygen
(B) Fight infections
(C) Carry glucose
(D) Form bile
Answer: (B) Fight infections
Excretory System
17. The main organs responsible for removing nitrogenous wastes from the blood are the:
(A) Lungs
(B) Kidneys
(C) Liver
(D) Heart
Answer: (B) Kidneys
18. The structural and functional unit of the kidney is:
(A) Neuron
(B) Nephron
(C) Alveolus
(D) Villus
Answer: (B) Nephron
19. Which substance is normally excreted in urine?
(A) Urea
(B) Oxygen
(C) Haemoglobin
(D) Starch
Answer: (A) Urea
20. The kidneys help maintain the body’s:
(A) Water and electrolyte balance
(B) Oxygen production
(C) Bile production
(D) Bone length
Answer: (A) Water and electrolyte balance
Nervous System
21. The basic structural and functional unit of the nervous system is the:
(A) Nephron
(B) Neuron
(C) Alveolus
(D) Platelet
Answer: (B) Neuron
22. Which part of the brain is mainly responsible for thinking, memory and voluntary actions?
(A) Cerebrum
(B) Cerebellum
(C) Medulla oblongata
(D) Spinal cord
Answer: (A) Cerebrum
23. Which part of the brain helps maintain balance and coordination?
(A) Cerebrum
(B) Cerebellum
(C) Hypothalamus
(D) Medulla
Answer: (B) Cerebellum
24. The medulla oblongata controls many:
(A) Voluntary movements only
(B) Involuntary functions such as breathing and heart rate
(C) Digestive enzymes only
(D) Bone movements
Answer: (B) Involuntary functions such as breathing and heart rate
Endocrine System
25. Which gland is commonly called the “master gland”?
(A) Thyroid
(B) Pituitary
(C) Adrenal
(D) Pancreas
Answer: (B) Pituitary
26. Which hormone regulates blood glucose levels by lowering blood glucose?
(A) Adrenaline
(B) Insulin
(C) Thyroxine
(D) Growth hormone
Answer: (B) Insulin
27. The thyroid gland primarily produces:
(A) Insulin
(B) Thyroxine
(C) Adrenaline
(D) Estrogen
Answer: (B) Thyroxine
28. Iodine is essential for the production of:
(A) Insulin
(B) Thyroid hormones
(C) Adrenaline
(D) Haemoglobin
Answer: (B) Thyroid hormones
Reproductive System
29. In humans, fertilization normally occurs in the:
(A) Uterus
(B) Ovary
(C) Fallopian tube
(D) Vagina
Answer: (C) Fallopian tube
30. Which hormone is primarily responsible for the development of male secondary sexual characteristics?
(A) Estrogen
(B) Testosterone
(C) Insulin
(D) Thyroxine
Answer: (B) Testosterone
Bonus: Skeletal & Muscular System
31. The adult human skeleton normally contains approximately:
(A) 106 bones
(B) 206 bones
(C) 306 bones
(D) 406 bones
Answer: (B) 206 bones
32. Which is the longest bone in the human body?
(A) Tibia
(B) Femur
(C) Humerus
(D) Radius
Answer: (B) Femur
33. Which type of muscle is found in the walls of the intestine?
(A) Skeletal muscle
(B) Smooth muscle
(C) Cardiac muscle
(D) Voluntary muscle
Answer: (B) Smooth muscle
34. Cardiac muscle is found in the:
(A) Brain
(B) Heart
(C) Stomach
(D) Kidney
Answer: (B) Heart
35. Which type of muscle is generally under voluntary control?
(A) Smooth muscle
(B) Cardiac muscle
(C) Skeletal muscle
(D) Visceral muscle
Answer: (C) Skeletal muscle
Must-Memorize: Human Body
| Organ / Structure | Main Function |
|---|---|
| Mouth | Starts carbohydrate digestion |
| Stomach | Protein digestion begins |
| Liver | Produces bile; metabolism/detoxification |
| Gallbladder | Stores bile |
| Pancreas | Digestive enzymes + insulin |
| Small intestine | Most digestion and nutrient absorption |
| Large intestine | Mainly water/electrolyte absorption and feces formation |
| Lungs | Gas exchange |
| Alveoli | Exchange of O₂ and CO₂ |
| Heart | Pumps blood |
| RBC | Oxygen transport |
| WBC | Immune defence |
| Platelets | Blood clotting |
| Kidney | Filtration and urine formation |
| Nephron | Functional unit of kidney |
| Brain | Control and coordination |
| Cerebrum | Thinking, memory, voluntary actions |
| Cerebellum | Balance and coordination |
| Medulla | Many involuntary functions |
| Neuron | Nerve impulse transmission |
| Pituitary | Major regulatory endocrine gland |
| Thyroid | Thyroid hormones |
| Pancreas | Insulin |
| Adrenal glands | Adrenal hormones including adrenaline |
| Fallopian tube | Usual site of fertilization |
| Femur | Longest bone |
| Skeletal muscle | Voluntary movement |
| Cardiac muscle | Heart contraction |
| Smooth muscle | Involuntary movement of internal organs |