MDCAT Biology chapter 14: Biology · Digestion MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
27 exam-style questions on Biology · Digestion, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. A gallstone blocks the common bile duct. Which pair of signs is most likely?
A
yellow skin and unusually dark brown faeces
B
normal skin colour and pale, clay-coloured faeces
C
normal skin colour and dark, watery faeces
D
yellow skin and pale, clay-coloured faeces
Show answer
Answer: D. Bile pigments cannot leave through the duct, so they pass back into the blood and colour the skin yellow (jaundice), while the faeces lack the pigments that normally make them brown.
2. A patient whose bile duct is blocked absorbs fats poorly. Which vitamin is he also most likely to absorb poorly?
A
vitamin B12
B
vitamin B1
C
vitamin K
D
vitamin C
Show answer
Answer: C. Vitamin K is fat-soluble, so it is absorbed together with the products of fat digestion, which need bile salts. Vitamins C and B are water-soluble and are absorbed without bile.
3. Which feature of a villus mainly keeps a steep concentration gradient for the absorption of glucose?
A
smooth muscle fibres that keep the villus upright
B
a rich capillary network that carries glucose away
C
a central lacteal that collects glucose into the lymph
D
goblet cells that secrete mucus over the surface
Show answer
Answer: B. Blood flowing through the capillaries of the villus removes absorbed glucose at once, so its concentration inside the villus stays low. The lacteal absorbs fats, not glucose.
4. A baby is born with the ring of muscle at the exit of the stomach so thick that milk cannot pass into the intestine and is vomited. The structure affected is the
A
anal sphincter
B
ileocaecal valve
C
cardiac sphincter
D
pyloric sphincter
Show answer
Answer: D. The pyloric sphincter guards the opening from the stomach into the duodenum. The cardiac sphincter lies where the oesophagus enters the stomach.
5. A patient with severe liver damage bleeds for a long time after a minor cut. This is mainly because the liver normally
A
makes the red blood cells that form a blood clot
B
produces the white blood cells that seal a wound
C
makes clotting proteins such as fibrinogen
D
stores the platelets needed to plug a damaged vessel
Show answer
Answer: C. Fibrinogen and prothrombin are plasma proteins made in the liver; without them a clot cannot form. Platelets and blood cells are made in the red bone marrow.
6. Bacteria that live in the human colon are useful because they synthesise
A
vitamin A
B
vitamin D
C
vitamin C
D
vitamin K
Show answer
Answer: D. Colon bacteria make vitamin K, needed for blood clotting, which is then absorbed. Vitamin D is made in the skin in sunlight.
7. When food, especially protein, enters the stomach, cells in the stomach wall release a hormone into the blood that makes the gastric glands secrete more gastric juice. This hormone is
A
insulin
B
gastrin
C
secretin
D
cholecystokinin
Show answer
Answer: B. Gastrin is made in the stomach wall and acts on the gastric glands. Secretin and cholecystokinin come from the duodenum and act on the pancreas and gall bladder.
8. A family develops fever, stomach cramps, vomiting and diarrhoea a day after eating undercooked chicken and eggs. The most likely cause is the bacterium
A
Streptococcus pneumoniae
B
Mycobacterium tuberculosis
C
Helicobacter pylori
D
Salmonella
Show answer
Answer: D.Salmonella from poorly cooked poultry and eggs is a common cause of food poisoning. Helicobacter pylori is linked with peptic ulcers, not with sudden illness after a meal.
9. Which of the following is NOT a function of the liver?
A
secreting insulin
B
storing glycogen
C
making bile
D
deamination of excess amino acids
Show answer
Answer: A. Insulin is secreted by the β cells of the islets of Langerhans in the pancreas. The liver makes bile, stores glycogen and deaminates surplus amino acids, forming urea.
10. The pancreas is described as a mixed gland because it
A
produces red blood cells as well as digestive enzymes
B
sends juice into a duct and hormones into the blood
C
makes bile as well as several digestive enzymes
D
secretes both acid and alkali into the duodenum
Show answer
Answer: B. Its acini are exocrine and pour pancreatic juice through the pancreatic duct into the duodenum; its islets of Langerhans are endocrine and release insulin and glucagon into the blood. Bile is made by the liver.
27, each with the answer and a short explanation, across 2 topics: Alimentary canal and enzymes, Absorption, liver and disorders. Every chapter test draws ten of them, so you can take it many times.
Is the MDCAT Biology chapter 14 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
