1. The human digestive system starts with _______________.
A) Esophagus
B) Mouth
C) Stomach
D) Small intestine
Answer: B
Explanation: Digestion begins in the mouth with chewing and salivary enzymes.
2. The longest part of the human digestive system is_______________.
A) Esophagus
B) Stomach
C) Small intestine
D) Large intestine
Answer: C
Explanation: Small intestine (~6 m) is longest, main site for digestion & absorption.
3. The total length of human alimentary canal is about_______________.
A) 3 m
B) 6 m
C) 9 m
D) 12 m
Answer: C
Explanation: Entire alimentary canal (mouth to anus) is ~9 meters.
4. Food pipe is also known as_______________.
A) Trachea
B) Esophagus
C) Larynx
D) Duodenum
Answer: B
Explanation: Esophagus carries swallowed food to stomach by peristalsis.
5. The stomach is located in_______________.
A) Thoracic cavity
B) Cranial cavity
C) Abdominal cavity
D) Pelvic cavity
Answer: C
Explanation: Stomach lies in upper left abdomen.
6. The part of small intestine connected to stomach is_______________.
A) Ileum
B) Duodenum
C) Jejunum
D) Cecum
Answer: B
Explanation: Duodenum receives chyme from stomach and secretions from liver & pancreas.
7. The last part of the small intestine is_______________.
A) Duodenum
B) Jejunum
C) Ileum
D) Colon
Answer: C
Explanation: Ileum connects small intestine to large intestine.
8. The large intestine mainly absorbs_______________.
A) Proteins
B) Water and minerals
C) Vitamins
D) Fats
Answer: B
Explanation: Large intestine reabsorbs water, salts; forms feces.
9. Vermiform appendix is a part of_______________.
A) Stomach
B) Large intestine
C) Small intestine
D) Pancreas
Answer: B
Explanation: Appendix is a small projection from cecum of large intestine.
10. The main function of the stomach is_______________.
A) Absorption of nutrients
B) Storage and partial digestion of food
C) Water absorption
D) Vitamin absorption
Answer: B
Explanation: Stomach stores food, mixes with gastric juice, begins protein digestion.
11. The finger-like projections in small intestine that increase surface area are_______________.
A) Microvilli
B) Papillae
C) Villi
D) Cilia
Answer: C
Explanation: Villi + microvilli increase absorptive surface area.
12. Which organ produces bile?
A) Pancreas
B) Liver
C) Gall bladder
D) Stomach
Answer: B
Explanation: Liver secretes bile, stored in gall bladder.
13. Bile is stored in_______________.
A) Pancreas
B) Gall bladder
C) Duodenum
D) Stomach
Answer: B
Explanation: Gall bladder stores and releases bile into duodenum.
14. Which organ produces digestive enzymes and hormones?
A) Stomach
B) Pancreas
C) Liver
D) Duodenum
Answer: B
Explanation: Pancreas secretes pancreatic juice (enzymes) + insulin & glucagon (hormones).
15. Which part of alimentary canal has acidic pH?
A) Mouth
B) Stomach
C) Duodenum
D) Ileum
Answer: B
Explanation: Gastric juice (HCl) makes stomach acidic (pH ~1.5–2.5).
16. Which part of small intestine receives bile and pancreatic juice?
A) Ileum
B) Duodenum
C) Jejunum
D) Colon
Answer: B
Explanation: Duodenum receives secretions for chemical digestion.
17. Which part of alimentary canal absorbs maximum nutrients?
A) Stomach
B) Small intestine
C) Large intestine
D) Rectum
Answer: B
Explanation: Small intestine is major site of nutrient absorption.
18. Which part of alimentary canal absorbs maximum water?
A) Stomach
B) Small intestine
C) Large intestine
D) Rectum
Answer: C
Explanation: Large intestine reabsorbs water → solid feces.
19. Tongue is attached to floor of mouth by_______________.
A) Epiglottis
B) Frenulum
C) Uvula
D) Tonsil
Answer: B
Explanation: Frenulum is fold of mucous membrane fixing tongue.
20. The valve between stomach and duodenum is_______________.
A) Ileocecal valve
B) Pyloric sphincter
C) Cardiac sphincter
D) Anal sphincter
Answer: B
Explanation: Pyloric sphincter regulates passage of food into duodenum.
21. Which organ secretes hydrochloric acid?
A) Pancreas
B) Liver
C) Stomach
D) Duodenum
Answer: C
Explanation: Parietal cells of stomach secrete HCl.
22. Which organ neutralizes acidic chyme with alkaline juice?
A) Liver
B) Pancreas
C) Duodenum
D) Colon
Answer: B
Explanation: Pancreatic juice (bicarbonate) neutralizes stomach acid.
23. Rectum ends in_______________.
A) Cecum
B) Colon
C) Anus
D) Appendix
Answer: C
Explanation: Rectum stores feces before excretion through anus.
24. The epiglottis prevents food from entering_______________.
A) Esophagus
B) Larynx (windpipe)
C) Stomach
D) Pharynx
Answer: B
Explanation: Epiglottis closes windpipe during swallowing.
25. Which part of the large intestine is blind-ended?
A) Cecum
B) Colon
C) Rectum
D) Appendix
Answer: A
Explanation: Cecum is a blind pouch at the junction of small and large intestine.
26. The digestive enzyme present in saliva is_______________.
A) Pepsin
B) Ptyalin (salivary amylase)
C) Trypsin
D) Lipase
Answer: B
Explanation: Salivary amylase breaks down starch into maltose in mouth.
27. The pH of saliva is about_______________.
A) Acidic (2–3)
B) Neutral to slightly alkaline (6.7–7.4)
C) Strongly alkaline (10–11)
D) Highly acidic (1–2)
Answer: B
Explanation: Saliva provides an optimal pH for amylase activity.
28. The main enzyme of gastric juice is_______________.
A) Trypsin
B) Pepsin
C) Ptyalin
D) Amylase
Answer: B
Explanation: Pepsin digests proteins into peptides in the stomach.
29. Gastric juice contains_______________.
A) HCl, pepsinogen, mucus
B) Bile salts only
C) Salivary enzymes only
D) Trypsin and amylase
Answer: A
Explanation: Gastric juice contains acid (HCl), enzyme precursor (pepsinogen), and protective mucus.
30. Pepsin is secreted in an inactive form called_______________.
A) Trypsinogen
B) Zymase
C) Pepsinogen
D) Renin
Answer: C
Explanation: HCl activates pepsinogen into pepsin.
31. The enzyme that coagulates milk in infants is_______________.
A) Pepsin
B) Renin (chymosin)
C) Trypsin
D) Amylase|
Answer: B
Explanation: Gastric enzyme renin helps in milk digestion in infants.
32. Which cells in the stomach secrete HCl?
A) Chief cells
B) Parietal (oxyntic) cells
C) Goblet cells
D) Kupffer cells
Answer: B
Explanation: Parietal cells secrete hydrochloric acid.
33. Which cells of the stomach secrete pepsinogen?
A) Chief cells
B) Parietal cells
C) Goblet cells
D) Endocrine cells
Answer: A
Explanation: Chief cells release pepsinogen (inactive enzyme).
34. The hormone that stimulates secretion of gastric juice is_______________.
A) Secretin
B) Gastrin
C) Cholecystokinin
D) Enterokinase
Answer: B
Explanation: Gastrin (from stomach wall) stimulates gastric juice secretion.
35. Bile contains_______________.
A) Enzymes
B) Bile salts and pigments
C) Enzymes and mucus
D) Hormones
Answer: B
Explanation: Bile has no enzymes, but bile salts emulsify fats.
36. The yellow-green pigment in bile is_______________.
A) Bilirubin and biliverdin
B) Hemoglobin
C) Carotene
D) Urochrome
Answer: A
Explanation: Bile pigments are breakdown products of hemoglobin.
37. Which enzyme activates trypsinogen to trypsin?
A) Pepsin
B) Enterokinase
C) Amylase
D) Lipase
Answer: B
Explanation: Enterokinase (from intestinal mucosa) converts trypsinogen → trypsin.
38. Pancreatic juice contains_______________.
A) Amylase, lipase, trypsinogen
B) Pepsin, renin, amylase
C) Ptyalin, pepsin, lipase
D) None
Answer: A
Explanation: Pancreatic juice digests starch, fats, and proteins.
39. Trypsin acts on_______________.
A) Starch
B) Proteins
C) Lipids
D) Nucleic acids
Answer: B
Explanation: Trypsin breaks proteins into peptides.
40. Lipase acts on_______________.
A) Carbohydrates
B) Proteins
C) Fats
D) Minerals
Answer: C
Explanation: Lipase hydrolyzes fats into fatty acids and glycerol.
41. Amylase acts on_______________.
A) Proteins
B) Fats
C) Starch
D) Minerals
Answer: C
Explanation: Amylase converts starch into maltose.
42. Which enzyme digests nucleic acids?
A) Lipase
B) Nuclease (DNAse & RNAse)
C) Trypsin
D) Amylase
Answer: B
Explanation: Nucleases break nucleic acids into nucleotides.
43. The enzyme maltase converts maltose into_______________.
A) Glucose
B) Galactose
C) Fructose
D) Lactose
Answer: A
Explanation: Maltase splits maltose (disaccharide) into two glucose molecules.
44. The enzyme lactase converts lactose into_______________.
A) Glucose + Galactose
B) Glucose + Fructose
C) Glucose + Glucose
D) Sucrose
Answer: A
Explanation: Lactase breaks down milk sugar (lactose).
45. The enzyme sucrase converts sucrose into_______________.
A) Glucose + Galactose
B) Glucose + Fructose
C) Glucose + Glucose
D) Lactose
Answer: B
Explanation: Sucrase hydrolyzes cane sugar (sucrose).
46. Which hormone stimulates pancreas to release digestive enzymes?
A) Gastrin
B) Secretin
C) Cholecystokinin (CCK)
D) Insulin
Answer: C
Explanation: CCK stimulates pancreatic enzyme secretion & gall bladder contraction.
47. Which hormone stimulates pancreas to release bicarbonate-rich juice?
A) Gastrin
B) Secretin
C) Insulin
D) Renin
Answer: B
Explanation: Secretin stimulates pancreatic bicarbonate to neutralize acidic chyme.
48. Which enzyme is absent in gastric juice?
A) Pepsin
B) Lipase
C) Amylase
D) Renin
Answer: C
Explanation: Gastric juice has no carbohydrate-digesting enzyme.
49. Which enzyme breaks proteins into peptides in the stomach?
A) Trypsin
B) Pepsin
C) Lipase
D) Amylase
Answer: B
Explanation: Pepsin acts on proteins in acidic medium.
50. Which digestive secretion emulsifies fats but contains no enzymes?
A) Saliva
B) Gastric juice
C) Bile
D) Pancreatic juice
Answer: C
Explanation: Bile salts emulsify fats into tiny droplets → easier digestion.
51. End product of carbohydrate digestion is_______________.
A) Starch
B) Maltose
C) Glucose
D) Glycogen
Answer: C
Explanation: Carbohydrates are broken down into glucose, which is absorbed in the small intestine.
52. End product of protein digestion is_______________.
A) Peptides
B) Amino acids
C) Polypeptides
D) Nucleotides
Answer: B
Explanation: Proteins → peptides → amino acids, absorbed into blood.
53. End product of fat digestion is_______________.
A) Glycerol + fatty acids
B) Polypeptides
C) Glucose
D) Cholesterol
Answer: A
Explanation: Lipase breaks fats into glycerol + fatty acids.
54. Carbohydrate digestion starts in_______________.
A) Stomach
B) Mouth
C) Small intestine
D) Large intestine
Answer: B
Explanation: Salivary amylase begins starch digestion in mouth.
55. Protein digestion starts in_______________.
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
Answer: B
Explanation: Pepsin begins protein digestion in acidic stomach environment.
56. Fat digestion starts in_______________.
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
Answer: C
Explanation: Fat digestion starts in duodenum with bile salts + lipase.
57. Main site of absorption of nutrients is_______________.
A) Stomach
B) Small intestine
C) Large intestine
D) Rectum
Answer: B
Explanation: Villi in small intestine absorb nutrients efficiently.
58. Glucose and amino acids are absorbed into_______________.
A) Lymph
B) Blood capillaries
C) Gall bladder
D) Pancreatic duct
Answer: B
Explanation: Glucose & amino acids enter blood vessels of villi.
59. Fatty acids and glycerol are absorbed into_______________.
A) Blood
B) Lymph (lacteals)
C) Liver directly
D) Kidneys
Answer: B
Explanation: Fats enter lymphatic system as chylomicrons.
60. Vitamins A, D, E, K are absorbed along with_______________.
A) Proteins
B) Carbohydrates
C) Fats
D) Minerals
Answer: C
Explanation: Fat-soluble vitamins require dietary fat for absorption.
61. Water-soluble vitamins are absorbed in_______________.
A) Stomach
B) Large intestine
C) Small intestine
D) Rectum
Answer: C
Explanation: B-complex & Vitamin C absorbed in small intestine.
62. Minerals like calcium are absorbed in presence of_______________.
A) Vitamin A
B) Vitamin D
C) Vitamin K
D) Vitamin B12
Answer: B
Explanation: Vitamin D promotes calcium absorption in intestine.
63. Iron absorption is enhanced by_______________.
A) Vitamin C
B) Vitamin A
C) Vitamin B1
D) Vitamin K
Answer: A
Explanation: Ascorbic acid reduces Fe³⁺ to Fe²⁺, aiding absorption.
64. Which process moves food along alimentary canal?
A) Osmosis
B) Peristalsis
C) Active transport
D) Diffusion
Answer: B
Explanation: Peristalsis = rhythmic contractions of smooth muscles pushing food.
65. Most water absorption occurs in_______________.
A) Stomach
B) Small intestine
C) Large intestine
D) Rectum
Answer: B
Explanation: Though large intestine also absorbs, most water is absorbed in small intestine.
66. Bile salts help in digestion of_______________.
A) Proteins
B) Fats
C) Carbohydrates
D) Nucleic acids
Answer: B
Explanation: Bile salts emulsify fats into small droplets for enzyme action.
67. The brush border of villi contains enzymes for_______________.
A) Fat digestion
B) Carbohydrate and protein digestion
C) Water absorption only
D) Vitamin storage
Answer: B
Explanation: Brush border enzymes like maltase, lactase, peptidase complete digestion.
68. Which sugar is absorbed by facilitated diffusion?
A) Glucose
B) Galactose
C) Fructose
D) Maltose
Answer: C
Explanation: Fructose absorption occurs via facilitated diffusion.
69. Glucose absorption in intestine occurs by_______________.
A) Passive diffusion
B) Active transport
C) Facilitated diffusion
D) Osmosis
Answer: B
Explanation: Glucose is absorbed by sodium-linked active transport.
70. Amino acids absorption occurs mainly by_______________.
A) Passive diffusion
B) Active transport
C) Simple osmosis
D) Facilitated diffusion
Answer: B
Explanation: Amino acids use carrier proteins + energy for absorption.
71. Which nutrient is absorbed into lacteals of villi?
A) Glucose
B) Amino acids
C) Fatty acids & glycerol
D) Minerals
Answer: C
Explanation: Fats → chylomicrons → lymphatic lacteals.
72. Which part of intestine is most active in absorption?
A) Duodenum
B) Jejunum
C) Ileum
D) Cecum
Answer: B
Explanation: Jejunum is primary site for absorption of nutrients.
73. Which part of small intestine absorbs bile salts & Vitamin B12?
A) Duodenum
B) Jejunum
C) Ileum
D) Colon
Answer: C
Explanation: Ileum specifically absorbs bile salts and B12.
74. In humans, most digestion of food takes place in_______________.
A) Stomach
B) Mouth
C) Small intestine
D) Large intestine
Answer: C
Explanation: Enzymes from pancreas + bile + intestinal juice → major digestion in small intestine.
75. In humans, most absorption of food occurs in_______________.
A) Stomach
B) Small intestine
C) Large intestine
D) Rectum
Answer: B
Explanation: Villi & microvilli → large surface area → maximum absorption.
76. Inflammation of the appendix is called_______________.
A) Hepatitis
B) Appendicitis
C) Gastritis
D) Colitis
Answer: B
Explanation: Appendicitis = inflammation of vermiform appendix, may require surgery.
77. Inflammation of the liver is called_______________.
A) Hepatitis
B) Gastritis
C) Pancreatitis
D) Colitis
Answer: A
Explanation: Hepatitis is caused by viral infection, alcohol, or toxins.
78. Yellowing of skin and eyes due to liver dysfunction is_______________.
A) Anemia
B) Jaundice
C) Rickets
D) Scurvy
Answer: B
Explanation: Jaundice occurs due to excess bilirubin in blood.
79. Gallstones are formed due to precipitation of_______________.
A) Calcium
B) Cholesterol and bile pigments
C) Uric acid
D) Proteins
Answer: B
Explanation: Gallstones block bile duct, causing pain and indigestion.
80. The condition in which gastric acid enters esophagus is_______________.
A) Gastritis
B) Acid reflux / GERD
C) Ulcer
D) Hernia
Answer: B
Explanation: Gastro-esophageal reflux disease causes heartburn.
81. Peptic ulcer is caused mainly due to infection by_______________.
A) E. coli
B) Helicobacter pylori
C) Salmonella
D) Streptococcus
Answer: B
Explanation: H. pylori damages stomach lining → ulcer formation.
82. Lack of which vitamin causes night blindness?
A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin K
Answer: A
Explanation: Vitamin A is important for vision in dim light.
83. Deficiency of Vitamin D causes_______________.
A) Rickets
B) Scurvy
C) Beriberi
D) Pellagra
Answer: A
Explanation: Vitamin D deficiency → weak bones, bowed legs in children.
84. Deficiency of Vitamin C causes_______________.
A) Pellagra
B) Scurvy
C) Beriberi
D) Rickets
Answer: B
Explanation: Vitamin C deficiency → bleeding gums, poor wound healing.
85. Lack of Vitamin K causes_______________.
A) Excess bleeding
B) Weak bones
C) Night blindness
D) Skin disorders
Answer: A
Explanation: Vitamin K is essential for clotting factor synthesis.
86. Which mineral is important for thyroid hormone synthesis?
A) Iron
B) Iodine
C) Calcium
D) Sodium
Answer: B
Explanation: Iodine deficiency → goiter (thyroid enlargement).
87. Which mineral is essential for hemoglobin formation?
A) Iodine
B) Calcium
C) Iron
D) Phosphorus
Answer: C
Explanation: Iron is a component of hemoglobin that binds oxygen.
88. Which mineral strengthens bones and teeth?
A) Sodium
B) Potassium
C) Calcium
D) Zinc
Answer: C
Explanation: Calcium + phosphorus form hydroxyapatite crystals in bones/teeth.
89. Kwashiorkor is caused due to deficiency of_______________.
A) Carbohydrates
B) Proteins
C) Fats
D) Vitamins
Answer: B
Explanation: Protein deficiency → swollen belly, edema, stunted growth.
90. Marasmus is caused due to deficiency of_______________.
A) Proteins only
B) Energy (proteins + calories)
C) Fats only
D) Vitamins only
Answer: B
Explanation: Severe malnutrition → muscle wasting, weakness.
91. Which disease is associated with deficiency of Vitamin B1 (Thiamine)?
A) Pellagra
B) Beriberi
C) Rickets
D) Scurvy
Answer: B
Explanation: B1 deficiency → nervous system and heart problems.
92. Pellagra is caused by deficiency of_______________.
A) Vitamin B2
B) Vitamin B3 (Niacin)
C) Vitamin B6
D) Vitamin B12
Answer: B
Explanation: Niacin deficiency → 3 Ds: dermatitis, diarrhea, dementia.
93. Deficiency of Vitamin B12 causes_______________.
A) Pernicious anemia
B) Rickets
C) Scurvy
D) Night blindness
Answer: A
Explanation: Lack of B12 → improper RBC maturation → anemia.
94. Which part of digestive system is most commonly affected in typhoid?
A) Large intestine
B) Small intestine (ileum)
C) Stomach
D) Rectum
Answer: B
Explanation: Typhoid (Salmonella typhi) affects ileum.
95. Goiter is caused by deficiency of_______________.
A) Iron
B) Calcium
C) Iodine
D) Phosphorus
Answer: C
Explanation: Iodine deficiency → thyroid enlargement.
96. Which organ secretes intrinsic factor required for Vitamin B12 absorption?
A) Liver
B) Stomach
C) Pancreas
D) Intestine
Answer: B
Explanation: Parietal cells secrete intrinsic factor for B12 absorption in ileum.
97. Xerophthalmia (dryness of eyes) is caused by deficiency of_______________.
A) Vitamin C
B) Vitamin A
C) Vitamin D
D) Vitamin K
Answer: B
Explanation: Vitamin A deficiency affects epithelial tissues and eyes.
98. Rickets in children and osteomalacia in adults are due to deficiency of_______________.
A) Vitamin A
B) Vitamin B1
C) Vitamin D
D) Vitamin K
Answer: C
Explanation: Vitamin D deficiency causes soft bones in both children and adults.
99. The enzyme deficiency causing lactose intolerance is_______________.
A) Maltase
B) Sucrase
C) Lactase
D) Amylase
Answer: C
Explanation: Lactase deficiency → inability to digest lactose in milk.
100. Which one is not a digestive disorder?
A) Appendicitis
B) Gastritis
C) Hypertension
D) Peptic ulcer
Answer: C
Explanation: Hypertension is circulatory, not digestive disorder.