Digestive System MCQ for RRB & SSC and other Competitive exams
31
The process of breaking large fat globules into smaller droplets is called?
✓ Answer:
C
Emulsification
Emulsification is the process by which bile salts break large fat globules into smaller fat droplets, increasing the surface area for lipase to act upon. This is NOT chemical digestion - the chemical structure of fats does not change, only the size of droplets decreases.
32
Bile is produced by which organ?
✓ Answer:
C
Liver
Bile is produced by the Liver and stored in the Gall Bladder. Bile emulsifies fats in the duodenum. The pancreas produces pancreatic juice. Gall bladder only stores, not produces bile.
33
Which vitamin requires intrinsic factor for its absorption in the intestine?
✓ Answer:
C
Vitamin B12
Vitamin B12 (Cobalamin) requires a special protein called Intrinsic Factor, secreted by the Parietal cells of the stomach, for absorption in the ileum. Deficiency of intrinsic factor leads to Pernicious Anaemia.
34
Which hormone stimulates the secretion of gastric juice?
✓ Answer:
B
Gastrin
Gastrin is a hormone secreted by the G cells of the stomach lining when food enters the stomach. It stimulates gastric glands to secrete more gastric juice (HCl and pepsinogen). Secretin stimulates pancreatic juice, and Cholecystokinin (CCK) stimulates bile release.
35
Absorption of digested fats occurs through which structures?
✓ Answer:
B
Lacteals
Digested fats (fatty acids and glycerol) are reassembled into triglycerides and packaged into Chylomicrons, which are absorbed into Lacteals (lymph capillaries inside villi). They enter the lymphatic system and eventually reach the bloodstream.
36
Which of the following is a function of HCl in the stomach?
✓ Answer:
B
Activating pepsinogen to pepsin
HCl in the stomach: activates Pepsinogen into Pepsin, creates acidic environment (pH 1-2) for pepsin to work, kills harmful bacteria in food, and denatures proteins making them easier to digest. It does NOT digest fats (that is lipase) or neutralize acids.
37
Which macronutrient is primarily digested in the mouth?
✓ Answer:
C
Carbohydrates
Carbohydrate digestion begins in the mouth via Salivary Amylase, which breaks starch into maltose. Protein digestion starts in the stomach (pepsin), and fat digestion mainly occurs in the small intestine (lipase). Vitamins don't require enzymatic digestion.
38
What is the condition called when the appendix becomes inflamed?
✓ Answer:
B
Appendicitis
Appendicitis is the inflammation of the vermiform appendix. It causes severe pain in the lower right abdomen. If untreated, the appendix can rupture, leading to Peritonitis (infection of the abdominal cavity). Treatment is surgical removal called Appendectomy.
39
The inner lining of the stomach is protected from HCl by?
✓ Answer:
B
Mucus
Mucus secreted by the Goblet cells of the stomach lining forms a protective layer that prevents self-digestion of the stomach wall by HCl and pepsin. When this mucus layer is damaged, it leads to Peptic Ulcers.
40
Gastric juice is secreted by which organ?
✓ Answer:
C
Stomach
Gastric juice is secreted by the gastric glands in the stomach lining. It contains HCl, Pepsinogen, and Mucus. HCl acidifies the stomach, pepsinogen is activated to pepsin for protein digestion, and mucus protects the stomach wall from self-digestion.