Here below some basic MCQ’s of “Digestion and Absorption” with answer which is explained in details. Let’s check one by one which is given below.
MCQ 1:
Which enzyme is responsible for the breakdown of carbohydrates in the mouth?
A) Amylase
B) Pepsin
C) Lipase
D) Lactase
Answer: A) Amylase
Explanation: Salivary amylase, also known as ptyalin, is an enzyme secreted by the salivary glands that begins the digestion of carbohydrates into simpler sugars.
MCQ 2:
Where does the majority of nutrient absorption occur in the human digestive system?
A) Stomach
B) Small intestine
C) Large intestine
D) Esophagus
Answer: B) Small intestine
Explanation: The small intestine, specifically the jejunum and ileum, is the primary site for nutrient absorption, including carbohydrates, proteins, and fats.
MCQ 3:
What is the role of bile in digestion?
A) To digest proteins
B) To emulsify fats
C) To absorb carbohydrates
D) To neutralize stomach acid
Answer: B) To emulsify fats
Explanation: Bile, produced by the liver and stored in the gallbladder, contains bile salts that emulsify fats, increasing their surface area for more effective digestion by lipases.
MCQ 4:
Which of the following nutrients is absorbed primarily in the large intestine?
A) Amino acids
B) Fatty acids
C) Water
D) Monosaccharides
Answer: C) Water
Explanation: The large intestine mainly absorbs water and electrolytes, helping to concentrate waste and maintain fluid balance in the body.
MCQ 5:
What is the main function of villi in the small intestine?
A) To secrete digestive enzymes
B) To increase surface area for absorption
C) To transport bile
D) To produce mucus
Answer: B) To increase surface area for absorption
Explanation: Villi are small, finger-like projections lining the small intestine that significantly increase the surface area, enhancing the absorption of nutrients.
MCQ 6:
Which part of the digestive system is primarily responsible for protein digestion?
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
Answer: B) Stomach
Explanation: The stomach contains pepsin, an enzyme that begins the digestion of proteins into peptides.
MCQ 7:
Which of the following substances is absorbed directly into the bloodstream from the digestive tract?
A) Triglycerides
B) Amino acids
C) Fatty acids
D) Monosaccharides
Answer: B) Amino acids
Explanation: Amino acids are absorbed directly into the bloodstream through the walls of the small intestine.
MCQ 8:
What role does hydrochloric acid play in the stomach?
A) Neutralizes enzymes
B) Activates digestive enzymes
C) Absorbs nutrients
D) Emulsifies fats
Answer: B) Activates digestive enzymes
Explanation: Hydrochloric acid creates an acidic environment that activates pepsinogen to pepsin, enabling protein digestion.
MCQ 9:
Which of the following structures increases the surface area of the small intestine?
A) Microvilli
B) Goblet cells
C) Plicae circulares
D) Both A and C
Answer: D) Both A and C
Explanation: Microvilli and plicae circulares increase the surface area for absorption in the small intestine.
MCQ 10:
Which enzyme breaks down lipids in the small intestine?
A) Amylase
B) Lipase
C) Protease
D) Lactase
Answer: B) Lipase
Explanation: Lipase is the enzyme responsible for breaking down fats into fatty acids and glycerol.
MCQ 11:
What is the primary function of the pancreas in digestion?
A) Secretion of bile
B) Production of digestive enzymes
C) Absorption of nutrients
D) Storage of fat
Answer: B) Production of digestive enzymes
Explanation: The pancreas produces digestive enzymes that help break down carbohydrates, proteins, and fats in the small intestine.
MCQ 12:
Which vitamin is primarily absorbed in the large intestine?
A) Vitamin A
B) Vitamin B12
C) Vitamin K
D) Vitamin C
Answer: C) Vitamin K
Explanation: Vitamin K is primarily absorbed in the large intestine, where bacteria synthesize it.
MCQ 13:
What is the primary function of saliva in digestion?
A) To digest fats
B) To moisten food and initiate digestion
C) To absorb nutrients
D) To neutralize stomach acid
Answer: B) To moisten food and initiate digestion
Explanation: Saliva moistens food and contains enzymes like amylase that begin carbohydrate digestion.
MCQ 14:
In which part of the digestive tract is most water reabsorbed?
A) Stomach
B) Small intestine
C) Large intestine
D) Esophagus
Answer: C) Large intestine
Explanation: The large intestine reabsorbs most of the water, helping to concentrate waste.
MCQ 15:
Which type of absorption requires energy?
A) Passive diffusion
B) Facilitated diffusion
C) Active transport
D) Osmosis
Answer: C) Active transport
Explanation: Active transport requires energy to move substances against their concentration gradient, such as the absorption of glucose.
MCQ 16:
What is the primary site of carbohydrate digestion?
A) Mouth
B) Stomach
C) Duodenum
D) Large intestine
Answer: C) Duodenum
Explanation: The duodenum is the first part of the small intestine where pancreatic amylase continues the digestion of carbohydrates.
MCQ 17:
Which of the following hormones stimulates the release of bile?
A) Insulin
B) Gastrin
C) Cholecystokinin (CCK)
D) Secretin
Answer: C) Cholecystokinin (CCK)
Explanation: CCK stimulates the gallbladder to release bile, which is essential for fat digestion.
MCQ 18:
What is the role of brush border enzymes?
A) To emulsify fats
B) To activate other enzymes
C) To digest carbohydrates and proteins
D) To absorb nutrients
Answer: C) To digest carbohydrates and proteins
Explanation: Brush border enzymes, located on the microvilli of the small intestine, help break down carbohydrates and proteins into absorbable units.
MCQ 19:
Which structure prevents the backflow of food from the stomach into the esophagus?
A) Pyloric sphincter
B) Cardiac sphincter
C) Ileocecal valve
D) Anal sphincter
Answer: B) Cardiac sphincter
Explanation: The cardiac sphincter (or lower esophageal sphincter) prevents the backflow of stomach contents into the esophagus.
MCQ 20:
What type of nutrient is primarily absorbed in the stomach?
A) Carbohydrates
B) Proteins
C) Fats
D) Vitamins
Answer: B) Proteins
Explanation: The stomach primarily digests proteins, which are broken down into peptides by pepsin.
MCQ 21:
Which of the following is a function of the large intestine?
A) Digestion of carbohydrates
B) Production of bile
C) Absorption of vitamins and minerals
D) Secretion of enzymes
Answer: C) Absorption of vitamins and minerals
Explanation: The large intestine absorbs water, electrolytes, and certain vitamins, including those produced by gut bacteria.
MCQ 22:
What component of bile aids in the digestion of fats?
A) Cholesterol
B) Bile salts
C) Bilirubin
D) Phospholipids
Answer: B) Bile salts
Explanation: Bile salts emulsify fats, making them easier for lipase to digest.
MCQ 23:
Which organ is responsible for the majority of nutrient absorption?
A) Stomach
B) Pancreas
C) Small intestine
D) Large intestine
Answer: C) Small intestine
Explanation: The small intestine is the primary site for nutrient absorption due to its extensive surface area.
MCQ 24:
What is the primary carbohydrate that the body uses for energy?
A) Sucrose
B) Lactose
C) Glucose
D) Fructose
Answer: C) Glucose
Explanation: Glucose is the primary energy source for cells and is absorbed directly into the bloodstream from the intestine.
MCQ 25:
What is the function of the ileocecal valve?
A) Prevents backflow from the stomach
B) Regulates the passage from the small intestine to the large intestine
C) Releases bile into the small intestine
D) Secretes digestive enzymes
Answer: B) Regulates the passage from the small intestine to the large intestine
Explanation: The ileocecal valve controls the flow of material from the ileum (small intestine) into the cecum (large intestine) and prevents backflow.
MCQ 26:
Which of the following enzymes is produced by the salivary glands?
A) Pepsin
B) Amylase
C) Lipase
D) Trypsin
Answer: B) Amylase
Explanation: Salivary amylase begins the process of carbohydrate digestion in the mouth.
MCQ 27:
Which type of cell in the stomach secretes hydrochloric acid?
A) Parietal cells
B) Chief cells
C) Goblet cells
D) Mucous cells
Answer: A) Parietal cells
Explanation: Parietal cells in the gastric glands of the stomach secrete hydrochloric acid, which aids in digestion and maintains an acidic environment.
MCQ 28:
Which part of the small intestine is primarily involved in the absorption of nutrients?
A) Duodenum
B) Jejunum
C) Ileum
D) All of the above
Answer: D) All of the above
Explanation: While all parts of the small intestine play a role, the jejunum and ileum are primarily responsible for nutrient absorption.
MCQ 29:
What is the primary form of lipid absorbed by intestinal cells?
A) Triglycerides
B) Fatty acids
C) Glycerol
D) Cholesterol
Answer: B) Fatty acids
Explanation: Fatty acids, along with monoglycerides, are absorbed by intestinal cells after lipid digestion.
MCQ 30:
Which vitamin is absorbed in the presence of intrinsic factor?
A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin B12
Answer: D) Vitamin B12
Explanation: Intrinsic factor, produced by the stomach, is necessary for the absorption of vitamin B12 in the small intestine.
MCQ 31:
What type of enzyme breaks down proteins into smaller peptides?
A) Amylase
B) Lipase
C) Protease
D) Lactase
Answer: C) Protease
Explanation: Proteases are enzymes that cleave peptide bonds, breaking down proteins into smaller peptides.
MCQ 32:
Which structure is responsible for the emulsification of fats?
A) Pancreas
B) Liver
C) Gallbladder
D) All of the above
Answer: D) All of the above
Explanation: The liver produces bile, which is stored in the gallbladder, and bile salts help emulsify fats in the small intestine.
MCQ 33:
Which of the following is NOT a component of gastric juice?
A) Hydrochloric acid
B) Pepsinogen
C) Amylase
D) Intrinsic factor
Answer: C) Amylase
Explanation: Amylase is not found in gastric juice; it is present in saliva and helps digest carbohydrates in the mouth.
MCQ 34:
What is the main function of the liver in digestion?
A) Secretes enzymes
B) Produces bile
C) Absorbs nutrients
D) Breaks down carbohydrates
Answer: B) Produces bile
Explanation: The liver produces bile, which is essential for the digestion and absorption of fats.
MCQ 35:
Which process allows for the movement of nutrients from the intestinal lumen into the blood?
A) Filtration
B) Diffusion
C) Absorption
D) Excretion
Answer: C) Absorption
Explanation: Absorption is the process by which nutrients move from the intestinal lumen into the bloodstream.
MCQ 36:
Which of the following is an active transport process?
A) Simple diffusion of oxygen
B) Glucose transport in the intestine
C) Osmosis of water
D) Passive transport of ions
Answer: B) Glucose transport in the intestine
Explanation: Glucose is absorbed through active transport in the intestinal lining, requiring energy.
MCQ 37:
Which component of the digestive system helps protect the stomach lining from acid?
A) Mucus
B) Bile
C) Saliva
D) Pancreatic juice
Answer: A) Mucus
Explanation: Mucus produced by the gastric mucosa protects the stomach lining from the corrosive effects of hydrochloric acid.
MCQ 38:
What is the primary carbohydrate stored in the liver?
A) Glycogen
B) Glucose
C) Fructose
D) Lactose
Answer: A) Glycogen
Explanation: Glycogen is the primary storage form of glucose in the liver and muscles, which can be converted back to glucose when needed.
MCQ 39:
Which type of fat is primarily digested in the stomach?
A) Saturated fat
B) Trans fat
C) Unsaturated fat
D) None of the above
Answer: D) None of the above
Explanation: While some lipid digestion occurs in the stomach, the primary digestion of fats occurs in the small intestine with the help of bile and lipase.
MCQ 40:
Which digestive enzyme is specific for lactose?
A) Amylase
B) Lactase
C) Maltase
D) Sucrase
Answer: B) Lactase
Explanation: Lactase is the enzyme that breaks down lactose into glucose and galactose.
MCQ 41:
What is the function of secretin in digestion?
A) Stimulates bile release
B) Inhibits gastric motility
C) Stimulates pancreatic juice secretion
D) Increases gastric acid production
Answer: C) Stimulates pancreatic juice secretion
Explanation: Secretin stimulates the pancreas to secrete bicarbonate-rich pancreatic juice to neutralize stomach acid in the small intestine.
MCQ 42:
Which organ plays a key role in detoxifying substances absorbed from the digestive tract?
A) Pancreas
B) Liver
C) Spleen
D) Kidney
Answer: B) Liver
Explanation: The liver detoxifies harmful substances absorbed from the digestive tract before they enter systemic circulation.
MCQ 43:
Which of the following nutrients is absorbed through the lymphatic system?
A) Glucose
B) Amino acids
C) Fatty acids
D) Vitamins
Answer: C) Fatty acids
Explanation: Fatty acids and monoglycerides are absorbed into the lymphatic system before entering the bloodstream, primarily through lacteals.
MCQ 44:
What role do pancreatic enzymes play in digestion?
A) Digestion of carbohydrates only
B) Digestion of proteins and fats only
C) Digestion of carbohydrates, proteins, and fats
D) None of the above
Answer: C) Digestion of carbohydrates, proteins, and fats
Explanation: Pancreatic enzymes, including amylase, proteases, and lipase, are responsible for the digestion of carbohydrates, proteins, and fats.
MCQ 45:
Which of the following is a primary function of the gallbladder?
A) Producing bile
B) Storing bile
C) Absorbing nutrients
D) Secreting digestive enzymes
Answer: B) Storing bile
Explanation: The gallbladder stores bile produced by the liver until it is needed for digestion in the small intestine.
MCQ 46:
What is the primary site of protein digestion?
A) Mouth
B) Stomach
C) Duodenum
D) Small intestine
Answer: B) Stomach
Explanation: Protein digestion begins in the stomach with the action of pepsin.
MCQ 47:
Which vitamin is synthesized by gut bacteria?
A) Vitamin A
B) Vitamin C
C) Vitamin K
D) Vitamin E
Answer: C) Vitamin K
Explanation: Gut bacteria synthesize vitamin K, which is important for blood clotting.
MCQ 48:
Which digestive enzyme is responsible for breaking down starches into sugars?
A) Lactase
B) Amylase
C) Sucrase
D) Maltase
Answer: B) Amylase
Explanation: Amylase is the enzyme that breaks down starches into simpler sugars.
MCQ 49:
What is the primary role of the pancreas in digestion?
A) Producing bile
B) Secreting digestive enzymes
C) Absorbing nutrients
D) Breaking down carbohydrates
Answer: B) Secreting digestive enzymes
Explanation: The pancreas secretes enzymes that digest carbohydrates, proteins, and fats in the small intestine.
MCQ 50:
Which part of the digestive system absorbs the majority of water?
A) Stomach
B) Small intestine
C) Large intestine
D) Esophagus
Answer: C) Large intestine
Explanation: The large intestine is primarily responsible for water absorption, concentrating waste for excretion.
MCQ 51:
What role do bile salts play in fat digestion?
A) Emulsification of fats
B) Protein digestion
C) Carbohydrate absorption
D) Vitamin absorption
Answer: A) Emulsification of fats
Explanation: Bile salts emulsify fats, increasing their surface area for digestion by lipases.
MCQ 52:
Which structure prevents the reflux of stomach contents into the esophagus?
A) Pyloric sphincter
B) Cardiac sphincter
C) Ileocecal valve
D) Anal sphincter
Answer: B) Cardiac sphincter
Explanation: The cardiac sphincter (lower esophageal sphincter) prevents the backflow of stomach contents into the esophagus.
MCQ 53:
Which of the following is a function of saliva?
A) Absorbing nutrients
B) Activating enzymes
C) Digestion of proteins
D) Emulsifying fats
Answer: B) Activating enzymes
Explanation: Saliva contains enzymes like amylase that begin the digestion of carbohydrates.
MCQ 54:
What is the main function of the intestinal villi?
A) Secretion of enzymes
B) Absorption of nutrients
C) Emulsification of fats
D) Digestion of proteins
Answer: B) Absorption of nutrients
Explanation: Villi increase the surface area of the intestinal lining, enhancing nutrient absorption.
MCQ 55:
Which of the following nutrients is absorbed via passive diffusion?
A) Glucose
B) Water
C) Amino acids
D) Vitamins
Answer: B) Water
Explanation: Water is absorbed by passive diffusion through osmosis across the intestinal lining.
MCQ 56:
Which of the following enzymes is secreted by the pancreas?
A) Pepsin
B) Amylase
C) Lactase
D) Maltase
Answer: B) Amylase
Explanation: The pancreas secretes amylase, which is involved in carbohydrate digestion in the small intestine.
MCQ 57:
What is the primary function of the stomach?
A) Absorption of nutrients
B) Mechanical digestion and initial protein digestion
C) Emulsification of fats
D) Storage of bile
Answer: B) Mechanical digestion and initial protein digestion
Explanation: The stomach mechanically churns food and initiates protein digestion through gastric juices.
MCQ 58:
Which hormone stimulates the secretion of gastric acid?
A) Secretin
B) Gastrin
C) Cholecystokinin
D) Insulin
Answer: B) Gastrin
Explanation: Gastrin is released in response to food intake and stimulates the stomach to secrete gastric acid.
MCQ 59:
What is the function of the pyloric sphincter?
A) Prevents food from entering the stomach
B) Regulates the passage of chyme into the duodenum
C) Secretes digestive enzymes
D) Absorbs nutrients
Answer: B) Regulates the passage of chyme into the duodenum
Explanation: The pyloric sphincter controls the movement of partially digested food (chyme) from the stomach into the small intestine.
MCQ 60:
Which of the following is NOT a carbohydrate?
A) Glucose
B) Fructose
C) Sucrose
D) Glycogen
E) Cholesterol
Answer: E) Cholesterol
Explanation: Cholesterol is a lipid, not a carbohydrate; the others are all types of carbohydrates.
MCQ 61:
What type of absorption involves the use of transport proteins?
A) Simple diffusion
B) Facilitated diffusion
C) Active transport
D) Both B and C
Answer: D) Both B and C
Explanation: Facilitated diffusion and active transport both utilize transport proteins to move substances across cell membranes.
MCQ 62:
Which digestive process occurs mainly in the small intestine?
A) Absorption of nutrients
B) Emulsification of fats
C) Protein digestion
D) All of the above
Answer: D) All of the above
Explanation: The small intestine is where the majority of nutrient absorption, fat emulsification, and protein digestion occur.
MCQ 63:
What is the main purpose of chewing food?
A) To increase flavor
B) To initiate protein digestion
C) To break food into smaller pieces for easier digestion
D) To absorb nutrients
Answer: C) To break food into smaller pieces for easier digestion
Explanation: Chewing mechanically breaks down food into smaller particles, increasing the surface area for enzymes to act upon.
MCQ 64:
Which organ is primarily responsible for detoxifying blood from the digestive tract?
A) Stomach
B) Pancreas
C) Liver
D) Spleen
Answer: C) Liver
Explanation: The liver processes and detoxifies substances absorbed from the digestive tract before they enter systemic circulation.
MCQ 65:
Which type of fat is more easily digested due to its structure?
A) Saturated fat
B) Trans fat
C) Unsaturated fat
D) All types of fat are equally digested
Answer: C) Unsaturated fat
Explanation: Unsaturated fats are generally easier to digest due to their lower melting point and less rigid structure compared to saturated fats.
MCQ 66:
What is the main function of intestinal microbiota?
A) Digestion of proteins
B) Production of digestive enzymes
C) Fermentation of undigested carbohydrates
D) Absorption of vitamins
Answer: C) Fermentation of undigested carbohydrates
Explanation: Intestinal microbiota ferment undigested carbohydrates and produce short-chain fatty acids and gases.
MCQ 67:
Which of the following enzymes is responsible for breaking down proteins in the stomach?
A) Amylase
B) Pepsin
C) Lipase
D) Sucrase
Answer: B) Pepsin
Explanation: Pepsin is the primary enzyme in the stomach that breaks down proteins into smaller peptides.
MCQ 68:
What is the main product of lipid digestion?
A) Glucose
B) Fatty acids and glycerol
C) Amino acids
D) Nucleotides
Answer: B) Fatty acids and glycerol
Explanation: Lipid digestion primarily results in the production of fatty acids and glycerol.
MCQ 69:
Which nutrient requires intrinsic factor for its absorption?
A) Vitamin C
B) Vitamin D
C) Vitamin B12
D) Vitamin A
Answer: C) Vitamin B12
Explanation: Intrinsic factor is essential for the absorption of vitamin B12 in the small intestine.
MCQ 70:
Which of the following is a primary function of bile?
A) To digest proteins
B) To emulsify fats
C) To absorb carbohydrates
D) To neutralize stomach acid
Answer: B) To emulsify fats
Explanation: Bile, produced by the liver, emulsifies fats, aiding their digestion and absorption in the small intestine.
MCQ 71:
Where does the digestion of carbohydrates begin?
A) Stomach
B) Mouth
C) Small intestine
D) Large intestine
Answer: B) Mouth
Explanation: Carbohydrate digestion begins in the mouth with the action of salivary amylase.
MCQ 72:
What is the role of gastric juice in digestion?
A) To absorb nutrients
B) To emulsify fats
C) To aid in protein digestion
D) To secrete bile
Answer: C) To aid in protein digestion
Explanation: Gastric juice contains hydrochloric acid and pepsin, which aid in the digestion of proteins.
MCQ 73:
Which of the following statements about the large intestine is true?
A) It absorbs the majority of nutrients.
B) It is responsible for protein digestion.
C) It absorbs water and electrolytes.
D) It secretes digestive enzymes.
Answer: C) It absorbs water and electrolytes.
Explanation: The large intestine primarily absorbs water and electrolytes, concentrating waste for excretion.
MCQ 74:
Which component of the digestive system is responsible for the final absorption of nutrients?
A) Stomach
B) Pancreas
C) Small intestine
D) Large intestine
Answer: C) Small intestine
Explanation: The small intestine is the main site for the final absorption of nutrients into the bloodstream.
MCQ 75:
What is the function of the rectum?
A) Digestion of carbohydrates
B) Storage of bile
C) Storage of feces
D) Absorption of nutrients
Answer: C) Storage of feces
Explanation: The rectum stores feces until they are expelled from the body during defecation.
MCQ 76:
Which of the following structures is involved in nutrient absorption?
A) Esophagus
B) Stomach
C) Villi
D) Gallbladder
Answer: C) Villi
Explanation: Villi are small, finger-like projections in the small intestine that increase surface area for nutrient absorption.
MCQ 77:
What is the primary role of the liver in metabolism?
A) Digestion of proteins
B) Storage of glucose
C) Production of digestive enzymes
D) Absorption of nutrients
Answer: B) Storage of glucose
Explanation: The liver stores glucose in the form of glycogen and regulates blood glucose levels.
MCQ 78:
Which enzyme breaks down sucrose into glucose and fructose?
A) Lactase
B) Amylase
C) Sucrase
D) Maltase
Answer: C) Sucrase
Explanation: Sucrase is the enzyme that breaks down sucrose into glucose and fructose.
MCQ 79:
Which digestive structure is primarily responsible for the absorption of fats?
A) Stomach
B) Small intestine
C) Large intestine
D) Pancreas
Answer: B) Small intestine
Explanation: The small intestine is the primary site for the absorption of fats, aided by bile and lipase.
MCQ 80:
What substance neutralizes stomach acid in the small intestine?
A) Bile
B) Pepsin
C) Bicarbonate
D) Amylase
Answer: C) Bicarbonate
Explanation: Bicarbonate, secreted by the pancreas, neutralizes stomach acid as chyme enters the small intestine.
MCQ 81:
Which of the following nutrients is absorbed through the intestinal walls into the lymphatic system?
A) Amino acids
B) Simple sugars
C) Fatty acids
D) Nucleotides
Answer: C) Fatty acids
Explanation: Fatty acids and monoglycerides are absorbed into the lymphatic system before entering the bloodstream.
MCQ 82:
What is the main function of the pancreas in relation to digestion?
A) Producing bile
B) Secreting digestive enzymes and bicarbonate
C) Absorbing nutrients
D) Storing nutrients
Answer: B) Secreting digestive enzymes and bicarbonate
Explanation: The pancreas produces digestive enzymes and bicarbonate to help neutralize stomach acid in the small intestine.
MCQ 83:
Which vitamin is primarily absorbed in the small intestine?
A) Vitamin B12
B) Vitamin K
C) Vitamin D
D) All of the above
Answer: D) All of the above
Explanation: Vitamins B12, K, D, and others are absorbed in the small intestine, although B12 requires intrinsic factor.
MCQ 84:
What role does fiber play in digestion?
A) Digests nutrients
B) Absorbs water
C) Regulates blood sugar
D) All of the above
Answer: D) All of the above
Explanation: Fiber aids in digestion by promoting bowel regularity, absorbing water, and helping to regulate blood sugar levels.
MCQ 85:
Which digestive enzyme is active in the acidic environment of the stomach?
A) Amylase
B) Trypsin
C) Pepsin
D) Lipase
Answer: C) Pepsin
Explanation: Pepsin is the enzyme that functions optimally in the acidic environment of the stomach to digest proteins.
MCQ 86:
What type of digestion occurs in the mouth?
A) Chemical digestion only
B) Mechanical digestion only
C) Both mechanical and chemical digestion
D) None of the above
Answer: C) Both mechanical and chemical digestion
Explanation: In the mouth, food is mechanically broken down by chewing and chemically digested by enzymes in saliva.
MCQ 87:
Which of the following is a function of the small intestine?
A) Production of bile
B) Absorption of nutrients
C) Storage of feces
D) Activation of pepsin
Answer: B) Absorption of nutrients
Explanation: The small intestine is primarily responsible for the absorption of nutrients from digested food.
MCQ 88:
What is the role of lactase in digestion?
A) Breaks down starches
B) Breaks down proteins
C) Breaks down lactose
D) Breaks down fats
Answer: C) Breaks down lactose
Explanation: Lactase is the enzyme that breaks down lactose, the sugar found in milk, into glucose and galactose.
MCQ 89:
Which part of the digestive system is responsible for the final stage of digestion and absorption?
A) Stomach
B) Duodenum
C) Jejunum
D) Ileum
Answer: D) Ileum
Explanation: The ileum is the final part of the small intestine where the majority of nutrient absorption occurs.
MCQ 90:
What is the main function of the cecum?
A) Digestion of carbohydrates
B) Absorption of water
C) Storage of bile
D) Fermentation of undigested food
Answer: D) Fermentation of undigested food
Explanation: The cecum, part of the large intestine, helps ferment undigested food material.
MCQ 91:
Which of the following is true about pancreatic juice?
A) It is alkaline.
B) It contains digestive enzymes.
C) It neutralizes stomach acid.
D) All of the above.
Answer: D) All of the above.
Explanation: Pancreatic juice is alkaline, contains digestive enzymes, and helps neutralize stomach acid in the small intestine.
MCQ 92:
Which of the following hormones is released in response to high blood glucose levels?
A) Glucagon
B) Insulin
C) Secretin
D) Gastrin
Answer: B) Insulin
Explanation: Insulin is released by the pancreas to help lower blood glucose levels by facilitating the uptake of glucose into cells.
MCQ 93:
What substance is produced by the liver and aids in fat digestion?
A) Pepsin
B) Bile
C) Amylase
D) Lipase
Answer: B) Bile
Explanation: Bile is produced by the liver and helps emulsify fats in the small intestine, making them easier to digest.
MCQ 94:
Which nutrient requires a sodium-dependent transport mechanism for absorption?
A) Glucose
B) Amino acids
C) Fatty acids
D) Both A and B
Answer: D) Both A and B
Explanation: Both glucose and certain amino acids are absorbed via sodium-dependent transport mechanisms in the small intestine.
MCQ 95:
What is the primary function of the large intestine?
A) Digestion of proteins
B) Absorption of nutrients
C) Absorption of water and electrolytes
D) Emulsification of fats
Answer: C) Absorption of water and electrolytes
Explanation: The large intestine’s primary role is to absorb water and electrolytes from indigestible food matter, forming solid waste.
MCQ 96:
Which enzyme is responsible for the digestion of triglycerides?
A) Amylase
B) Lipase
C) Pepsin
D) Maltase
Answer: B) Lipase
Explanation: Lipase is the enzyme that breaks down triglycerides into fatty acids and glycerol.
MCQ 97:
Which component of the digestive system produces intrinsic factor?
A) Liver
B) Stomach
C) Pancreas
D) Small intestine
Answer: B) Stomach
Explanation: The stomach produces intrinsic factor, which is necessary for the absorption of vitamin B12.
MCQ 98:
What type of carbohydrate is cellulose considered?
A) Simple sugar
B) Complex carbohydrate
C) Disaccharide
D) Monosaccharide
Answer: B) Complex carbohydrate
Explanation: Cellulose is a complex carbohydrate (fiber) that humans cannot digest but is important for gut health.
MCQ 99:
Which of the following substances does NOT aid in digestion?
A) Bile
B) Saliva
C) Gastric acid
D) Cholesterol
Answer: D) Cholesterol
Explanation: Cholesterol does not play a direct role in digestion, while bile, saliva, and gastric acid all aid in the digestive process.
MCQ 100:
What is the term for the rhythmic contractions that move food through the digestive tract?
A) Segmentation
B) Peristalsis
C) Absorption
D) Emulsification
Answer: B) Peristalsis
Explanation: Peristalsis refers to the wave-like muscle contractions that move food through the digestive tract.
MCQ 101:
Which hormone stimulates the gallbladder to release bile?
A) Insulin
B) Glucagon
C) Cholecystokinin
D) Gastrin
Answer: C) Cholecystokinin
Explanation: Cholecystokinin is released in response to fats in the duodenum and stimulates the gallbladder to release bile.
MCQ 102:
Which part of the digestive system is primarily responsible for the mechanical digestion of food?
A) Stomach
B) Small intestine
C) Large intestine
D) Esophagus
Answer: A) Stomach
Explanation: The stomach is primarily responsible for mechanical digestion through churning and mixing of food.
MCQ 103:
What is the function of the pyloric sphincter?
A) Controls the release of bile
B) Prevents backflow into the stomach
C) Regulates the passage of food into the small intestine
D) Secretes digestive enzymes
Answer: C) Regulates the passage of food into the small intestine
Explanation: The pyloric sphincter controls the flow of partially digested food from the stomach to the small intestine.
MCQ 104:
Which vitamin is essential for the synthesis of clotting factors?
A) Vitamin C
B) Vitamin K
C) Vitamin A
D) Vitamin E
Answer: B) Vitamin K
Explanation: Vitamin K is essential for the synthesis of certain clotting factors in the liver.
MCQ 105:
What is the primary site of carbohydrate digestion?
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
Answer: C) Small intestine
Explanation: Most carbohydrate digestion occurs in the small intestine, where enzymes like amylase act on starches.
MCQ 106:
Which structure in the small intestine increases the surface area for absorption?
A) Microvilli
B) Plicae circulares
C) Villi
D) All of the above
Answer: D) All of the above
Explanation: Microvilli, plicae circulares, and villi all contribute to increasing the surface area for absorption in the small intestine.
MCQ 107:
What is the primary role of gastric acid?
A) To digest carbohydrates
B) To kill pathogens
C) To emulsify fats
D) To neutralize bile
Answer: B) To kill pathogens
Explanation: Gastric acid helps kill pathogens present in food, providing an essential defense mechanism.
MCQ 108:
Which enzyme is responsible for the breakdown of starches?
A) Lactase
B) Sucrase
C) Amylase
D) Pepsin
Answer: C) Amylase
Explanation: Amylase breaks down starches into simpler sugars during digestion.
MCQ 109:
What type of transport is primarily involved in the absorption of glucose in the intestine?
A) Active transport
B) Facilitated diffusion
C) Simple diffusion
D) Osmosis
Answer: A) Active transport
Explanation: Glucose is absorbed through active transport, requiring energy and the presence of sodium ions.
MCQ 110:
Which of the following conditions can result from a deficiency of vitamin B12?
A) Anemia
B) Rickets
C) Night blindness
D) Scorbutic gums
Answer: A) Anemia
Explanation: Vitamin B12 deficiency can lead to megaloblastic anemia, characterized by large, immature red blood cells.
MCQ 111:
What is the primary function of the gallbladder?
A) To produce bile
B) To store bile
C) To secrete enzymes
D) To absorb nutrients
Answer: B) To store bile
Explanation: The gallbladder stores bile produced by the liver until it is needed for digestion in the small intestine.
MCQ 112:
Which part of the digestive system is primarily involved in the absorption of alcohol?
A) Stomach
B) Small intestine
C) Large intestine
D) Esophagus
Answer: A) Stomach
Explanation: Although alcohol is absorbed in both the stomach and small intestine, significant absorption occurs in the stomach.
MCQ 113:
What are the end products of protein digestion?
A) Glucose
B) Fatty acids
C) Amino acids
D) Nucleotides
Answer: C) Amino acids
Explanation: The end products of protein digestion are amino acids, which are absorbed into the bloodstream.
MCQ 114:
Which digestive enzyme is secreted in its inactive form?
A) Amylase
B) Pepsinogen
C) Lipase
D) Lactase
Answer: B) Pepsinogen
Explanation: Pepsinogen is secreted as an inactive precursor and is activated to pepsin in the acidic environment of the stomach.
MCQ 115:
Which of the following is NOT a function of the liver?
A) Producing bile
B) Metabolizing drugs
C) Absorbing nutrients
D) Storing vitamins
Answer: C) Absorbing nutrients
Explanation: The liver does not absorb nutrients; instead, it processes nutrients absorbed from the digestive tract.
MCQ 116:
Which of the following nutrients is primarily absorbed in the jejunum?
A) Proteins
B) Fats
C) Carbohydrates
D) All of the above
Answer: D) All of the above
Explanation: The jejunum is the part of the small intestine where the majority of nutrients, including proteins, fats, and carbohydrates, are absorbed.
MCQ 117:
Which digestive enzyme acts on nucleic acids?
A) Amylase
B) Pepsin
C) Nuclease
D) Lipase
Answer: C) Nuclease
Explanation: Nuclease is the enzyme that breaks down nucleic acids (DNA and RNA) into nucleotides.
MCQ 118:
What is the primary function of bile salts in digestion?
A) Emulsifying fats
B) Digestion of proteins
C) Absorbing carbohydrates
D) Breaking down nucleic acids
Answer: A) Emulsifying fats
Explanation: Bile salts emulsify fats, increasing their surface area for digestion by lipase enzymes.
MCQ 119:
Which of the following organs is NOT part of the digestive tract?
A) Stomach
B) Pancreas
C) Small intestine
D) Esophagus
Answer: B) Pancreas
Explanation: The pancreas is an accessory organ that produces digestive enzymes but is not part of the digestive tract itself.
MCQ 120:
What condition is characterized by the inability to digest lactose?
A) Lactose intolerance
B) Celiac disease
C) Gallstones
D) Peptic ulcer
Answer: A) Lactose intolerance
Explanation: Lactose intolerance occurs when the body lacks sufficient lactase to break down lactose, leading to digestive issues.
MCQ 121:
Which part of the brain regulates the digestive process?
A) Cerebrum
B) Cerebellum
C) Hypothalamus
D) Medulla oblongata
Answer: D) Medulla oblongata
Explanation: The medulla oblongata helps regulate autonomic functions, including some aspects of digestion.
MCQ 122:
Which of the following is a characteristic of the large intestine?
A) It has a larger diameter than the small intestine.
B) It is primarily responsible for nutrient absorption.
C) It contains villi.
D) It secretes digestive enzymes.
Answer: A) It has a larger diameter than the small intestine.
Explanation: The large intestine has a larger diameter compared to the small intestine and is mainly involved in water absorption and waste formation.
MCQ 123:
What is the role of secretin in digestion?
A) Stimulates bile release
B) Stimulates gastric acid secretion
C) Promotes pancreatic bicarbonate secretion
D) Activates pepsinogen
Answer: C) Promotes pancreatic bicarbonate secretion
Explanation: Secretin is released in response to acidic chyme entering the small intestine and stimulates the pancreas to secrete bicarbonate to neutralize the acid.
MCQ 124:
Which of the following substances is absorbed by active transport in the small intestine?
A) Water
B) Glucose
C) Fatty acids
D) Glycerol
Answer: B) Glucose
Explanation: Glucose is absorbed through active transport mechanisms in the small intestine, requiring energy.
MCQ 125:
What is the role of the ileocecal valve?
A) Prevents backflow of chyme
B) Controls the passage of bile
C) Regulates the entry of food into the stomach
D) Separates the small intestine from the large intestine
Answer: D) Separates the small intestine from the large intestine
Explanation: The ileocecal valve is located between the ileum (small intestine) and cecum (large intestine) and regulates the flow of chyme.
MCQ 126:
Which digestive hormone stimulates the pancreas to secrete digestive enzymes?
A) Gastrin
B) Cholecystokinin
C) Secretin
D) Insulin
Answer: B) Cholecystokinin
Explanation: Cholecystokinin (CCK) is released in response to fats and proteins in the small intestine and stimulates the pancreas to secrete digestive enzymes.
MCQ 127:
Which part of the digestive system is primarily responsible for detoxifying substances absorbed from the digestive tract?
A) Stomach
B) Small intestine
C) Pancreas
D) Liver
Answer: D) Liver
Explanation: The liver processes and detoxifies substances absorbed from the digestive tract before they enter the bloodstream.
MCQ 128:
Which type of fat is more likely to be solid at room temperature?
A) Unsaturated fats
B) Polyunsaturated fats
C) Saturated fats
D) Trans fats
Answer: C) Saturated fats
Explanation: Saturated fats tend to be solid at room temperature due to their chemical structure, which allows for tighter packing.
MCQ 129:
What is the primary carbohydrate found in milk?
A) Sucrose
B) Lactose
C) Glucose
D) Fructose
Answer: B) Lactose
Explanation: Lactose is the sugar present in milk, composed of glucose and galactose.
MCQ 130:
Which of the following digestive processes occurs in the stomach?
A) Absorption of nutrients
B) Digestion of carbohydrates
C) Digestion of proteins
D) Digestion of fats
Answer: C) Digestion of proteins
Explanation: The stomach is primarily responsible for protein digestion through the action of pepsin and gastric acid.
MCQ 131:
What is the main function of the appendix?
A) Digestion of proteins
B) Absorption of nutrients
C) Storage of bile
D) Immune function and gut flora maintenance
Answer: D) Immune function and gut flora maintenance
Explanation: The appendix is believed to play a role in immune function and serves as a reservoir for beneficial gut bacteria.
MCQ 132:
Which of the following enzymes is responsible for the digestion of fats?
A) Amylase
B) Pepsin
C) Lipase
D) Sucrase
Answer: C) Lipase
Explanation: Lipase is the enzyme that breaks down fats into fatty acids and glycerol during digestion.
MCQ 133:
Which nutrient is absorbed directly into the bloodstream without being digested?
A) Amino acids
B) Glucose
C) Vitamins
D) All of the above
Answer: D) All of the above
Explanation: Amino acids, glucose, and certain vitamins can be absorbed directly into the bloodstream without further digestion.
MCQ 134:
What is the primary role of the small intestine?
A) Storage of bile
B) Digestion of proteins
C) Absorption of nutrients
D) Production of digestive enzymes
Answer: C) Absorption of nutrients
Explanation: The small intestine’s primary role is to absorb nutrients from digested food into the bloodstream.
MCQ 135:
What is the primary function of gastric lipase?
A) Digestion of carbohydrates
B) Digestion of proteins
C) Digestion of fats
D) Emulsification of fats
Answer: C) Digestion of fats
Explanation: Gastric lipase is an enzyme that helps break down fats in the stomach, although most fat digestion occurs in the small intestine.
MCQ 136:
What is the main site for the absorption of water in the digestive system?
A) Stomach
B) Small intestine
C) Large intestine
D) Duodenum
Answer: C) Large intestine
Explanation: The large intestine is primarily responsible for absorbing water and electrolytes from indigestible food matter.
MCQ 137:
Which nutrient is primarily absorbed in the duodenum?
A) Proteins
B) Carbohydrates
C) Fats
D) All of the above
Answer: D) All of the above
Explanation: The duodenum is where the digestion of proteins, carbohydrates, and fats begins, and nutrients start to be absorbed.
MCQ 138:
Which hormone stimulates the secretion of gastric acid in the stomach?
A) Cholecystokinin
B) Secretin
C) Gastrin
D) Insulin
Answer: C) Gastrin
Explanation: Gastrin is released in response to food in the stomach and stimulates the secretion of gastric acid.
MCQ 139:
What type of digestion occurs in the small intestine through the action of bile?
A) Mechanical digestion
B) Chemical digestion
C) Emulsification
D) Absorption
Answer: C) Emulsification
Explanation: Bile emulsifies fats, increasing their surface area for digestive enzymes to act upon.
MCQ 140:
Which of the following is a characteristic of lipids?
A) Soluble in water
B) Contains nitrogen
C) Stores energy
D) Forms amino acids
Answer: C) Stores energy
Explanation: Lipids, including fats and oils, are important for energy storage and are insoluble in water.
MCQ 141:
What is the function of the salivary glands?
A) Producing bile
B) Secreting insulin
C) Producing saliva containing enzymes
D) Absorbing nutrients
Answer: C) Producing saliva containing enzymes
Explanation: Salivary glands produce saliva, which contains enzymes like amylase that initiate the digestion of carbohydrates.
MCQ 142:
Which vitamin is primarily absorbed in the ileum?
A) Vitamin A
B) Vitamin C
C) Vitamin B12
D) Vitamin K
Answer: C) Vitamin B12
Explanation: Vitamin B12 absorption occurs primarily in the ileum, and it requires intrinsic factor for absorption.
MCQ 143:
Which part of the digestive system has a microbiome that aids in digestion?
A) Stomach
B) Large intestine
C) Small intestine
D) Pancreas
Answer: B) Large intestine
Explanation: The large intestine hosts a diverse microbiome that helps in the fermentation of undigested materials and synthesizing certain vitamins.
MCQ 144:
What is the role of pancreatic enzymes in digestion?
A) They help emulsify fats.
B) They break down carbohydrates, fats, and proteins.
C) They neutralize stomach acid.
D) They absorb nutrients.
Answer: B) They break down carbohydrates, fats, and proteins.
Explanation: Pancreatic enzymes, including amylase, lipase, and proteases, are responsible for the digestion of carbohydrates, fats, and proteins in the small intestine.
MCQ 145:
Which enzyme is responsible for the digestion of starch into maltose?
A) Sucrase
B) Amylase
C) Lactase
D) Maltase
Answer: B) Amylase
Explanation: Amylase breaks down starch into maltose, a disaccharide.
MCQ 146:
What is the primary function of mucin in saliva?
A) To digest starch
B) To lubricate food
C) To neutralize acid
D) To break down fats
Answer: B) To lubricate food
Explanation: Mucin is a glycoprotein in saliva that lubricates food, making it easier to swallow.
MCQ 147:
Which of the following nutrients provides the most energy per gram?
A) Carbohydrates
B) Proteins
C) Fats
D) Vitamins
Answer: C) Fats
Explanation: Fats provide approximately 9 calories per gram, while carbohydrates and proteins provide about 4 calories per gram.
MCQ 148:
What is the term for the mixture of food and gastric juices in the stomach?
A) Chyme
B) Bolus
C) Feces
D) Emulsion
Answer: A) Chyme
Explanation: Chyme is the semi-liquid mixture of partially digested food and gastric juices that moves from the stomach to the small intestine.
MCQ 149:
Which type of carbohydrate is broken down into glucose during digestion?
A) Disaccharides
B) Monosaccharides
C) Polysaccharides
D) All of the above
Answer: D) All of the above
Explanation: Disaccharides (like sucrose and lactose) and polysaccharides (like starch) are broken down into glucose during digestion.
MCQ 150:
Which digestive enzyme is found in pancreatic juice and is responsible for protein digestion?
A) Amylase
B) Lipase
C) Trypsin
D) Sucrase
Answer: C) Trypsin
Explanation: Trypsin is a proteolytic enzyme found in pancreatic juice that digests proteins into smaller peptides.
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