Digestive System MCQ for RRB & SSC and other Competitive exams
91
What is the name of the process where glucose is converted to glycogen in the liver?
✓ Answer:
C
Glycogenesis
Glycogenesis = Glucose > Glycogen (storage in liver/muscle, stimulated by Insulin). Glycogenolysis = Glycogen > Glucose (stimulated by Glucagon). Gluconeogenesis = Non-carbohydrate sources > Glucose. Glycolysis = Glucose > Pyruvate (energy production).
92
Achlorhydria refers to the absence of which substance in gastric juice?
✓ Answer:
C
HCl
Achlorhydria is the medical condition characterized by the absence or low production of HCl in the stomach. This leads to impaired pepsinogen activation, poor protein digestion, bacterial overgrowth in the stomach, and impaired absorption of iron and Vitamin B12. Often associated with gastric atrophy and pernicious anaemia.
93
Which of the following is the function of dietary fibre in digestion?
✓ Answer:
C
Adds bulk to faeces and aids bowel movement
Dietary fibre (roughage) is not digested by human enzymes. It adds bulk to faeces, stimulates peristalsis, and aids regular bowel movements, preventing constipation. Some fibre is fermented by gut bacteria in the large intestine. High fibre intake reduces risk of colon cancer, diabetes, and heart disease.
94
Which of the following correctly matches the enzyme with its substrate?
✓ Answer:
D
Trypsin > Proteins
Correct enzyme-substrate pairs: Pepsin > Proteins (in stomach), Lipase > Fats/Triglycerides, Amylase > Starch/Carbohydrates, Trypsin > Proteins (in small intestine). Option D is the only correctly matched pair.
95
What is the name of the process by which the stomach churns food into chyme?
✓ Answer:
D
Churning
The stomach performs churning movements (mechanical digestion) that mix food with gastric juice to form chyme. Peristalsis is the wave-like movement along the digestive tract. Segmentation is the mixing movement in the small intestine. Mastication is chewing in the mouth.
96
What is the function of bicarbonate ions secreted by the pancreas?
✓ Answer:
C
Neutralize acidic chyme from the stomach
The pancreas secretes bicarbonate (HCO3-) rich juice into the duodenum to neutralize the highly acidic chyme (pH 1-2) coming from the stomach. This raises the pH of duodenal contents to approximately pH 7-8, creating an optimal alkaline environment for pancreatic and intestinal enzymes to function.
97
Which of the following disorders is caused by excess acid production in the stomach?
✓ Answer:
B
Peptic Ulcer
Peptic Ulcer is a sore/wound in the lining of the stomach or duodenum caused by excess HCl production or damage to the mucus lining (by H. pylori or NSAIDs). Symptoms include burning stomach pain, nausea, and bloating. Treatment includes antacids, H2 blockers, PPIs, and antibiotics.
98
Which of the following is the correct function of the colon?
✓ Answer:
C
Absorption of water and electrolytes
The Colon (large intestine) primarily absorbs water and electrolytes (Na+, K+, Cl-) from the remaining undigested material. It also hosts gut microbiota that produce Vitamin K and some B vitamins. The colon compacts waste into faeces for elimination.
99
Which of the following is the correct sequence of enzymes acting on carbohydrates?
✓ Answer:
C
Salivary Amylase > Pancreatic Amylase > Maltase
Carbohydrate digestion: Mouth - Salivary Amylase breaks starch into maltose. Small Intestine - Pancreatic Amylase further breaks remaining starch into maltose. Brush Border - Maltase breaks maltose into 2 glucose molecules. Pepsin and Trypsin are protein enzymes, Lipase digests fats.
100
Which of the following enzymes converts proteins into amino acids in the small intestine?
✓ Answer:
B
Trypsin and Chymotrypsin
In the small intestine, Trypsin and Chymotrypsin (from the pancreas) break down proteins and peptides into smaller peptides and amino acids. Further breakdown into individual amino acids is completed by Peptidases (aminopeptidase, dipeptidase) present on the brush border.