All (7)Unattempted (7)Skipped (0)Correct (0)Wrong (0)
Q.1
Based on: WBCS Prelims 2019
Who first described the enzyme alcohol dehydrogenase, which is crucial for alcohol metabolism in the liver?
A.Louis Pasteur
B.Efraim Racker
C.Hugo Theorell
D.Otto Warburg
Explanation
Why Correct: Hugo Theorell first isolated and characterized alcohol dehydrogenase from horse liver in 1935, earning him the Nobel Prize in Physiology or Medicine in 1955. Distractor Analysis: Louis Pasteur discovered the process of pasteurization and made contributions to germ theory. Efraim Racker identified the enzyme ATP synthase in oxidative phosphorylation. Otto Warburg discovered the Warburg effect in cancer cell metabolism. Takeaway: Alcohol dehydrogenase converts ethanol to acetaldehyde, a toxic intermediate that contributes to liver damage through oxidative stress.
Answer or skip previous question to unlock.
Q.2
Based on: WBCS Prelims 2014
Which stomach cell type secretes hydrochloric acid and intrinsic factor?
A.Chief cells
B.Parietal cells
C.Goblet cells
D.Enterochromaffin-like cells
Explanation
Why Correct: Parietal cells in the gastric glands secrete hydrochloric acid (HCl) and intrinsic factor needed for vitamin B12 absorption. Distractor Analysis: Chief cells secrete pepsinogen, the precursor to pepsin. Goblet cells secrete mucus and are found in the intestines and respiratory tract. Enterochromaffin-like cells secrete histamine that stimulates acid secretion. Takeaway: Intrinsic factor deficiency leads to pernicious anemia, a common exam link between stomach function and blood disorders.
Answer or skip previous question to unlock.
Q.3
Based on: WBCS Prelims 2014
What is the primary function of bile in digestion?
A.Emulsify fats into small droplets for lipase action
B.Break down proteins into peptides
C.Neutralise stomach acid in the duodenum
D.Digest carbohydrates into monosaccharides
Explanation
Why Correct: Bile salts emulsify fats into micelles, increasing surface area for lipase to hydrolyse triglycerides. Distractor Analysis: Pepsin and trypsin break down proteins into peptides. Pancreatic bicarbonate neutralises stomach acid in the duodenum. Salivary and pancreatic amylases digest carbohydrates into monosaccharides. Takeaway: Bile is produced by the liver, stored in the gallbladder, and released into the duodenum via the common bile duct. It contains no digestive enzymes; its action is mechanical emulsification.
Answer or skip previous question to unlock.
Q.4
Based on: WBCS Prelims 2011
Which hormone is produced by the beta cells of the islets of Langerhans in the pancreas and regulates blood glucose levels?
A.Pepsin
B.Insulin
C.Trypsin
D.Ptyalin
Explanation
Why Correct: Insulin is a peptide hormone secreted by pancreatic beta cells that lowers blood glucose by promoting cellular glucose uptake and glycogen synthesis. Distractor Analysis: Pepsin is a gastric protease that digests proteins in the stomach. Trypsin is a pancreatic protease that acts in the small intestine. Ptyalin (salivary amylase) breaks down starch in the mouth. Takeaway: Glucagon, secreted by pancreatic alpha cells, raises blood glucose by stimulating glycogenolysis and gluconeogenesis.
Answer or skip previous question to unlock.
Q.5
Based on: WBCS Prelims 2011
Who conducted pioneering studies on gastric digestion using a stomach fistula on Alexis St. Martin?
A.William Harvey
B.William Beaumont
C.Edward Jenner
D.Claude Bernard
Explanation
Why Correct: William Beaumont, an American surgeon, carried out the first detailed experiments on human digestion using Alexis St. Martin's gastric fistula between 1822 and 1833, discovering the role of hydrochloric acid and pepsin in the stomach. Distractor Analysis: William Harvey described the circulation of blood. Edward Jenner developed the smallpox vaccine. Claude Bernard pioneered the concept of the internal environment (milieu interieur).
Answer or skip previous question to unlock.
Q.6
Based on: WBCS Prelims 2011
Failure of which cell type in gastric glands leads to impaired activation of pepsinogen and increased risk of bacterial infection in the stomach?
A.Chief cells
B.Mucous neck cells
C.Parietal cells
D.G-cells
Explanation
Why Correct: Parietal cells secrete hydrochloric acid (HCl) which creates the acidic pH needed to convert pepsinogen to pepsin and also kills ingested bacteria. Failure of parietal cells reduces HCl, impairing pepsin activation and increasing infection risk. Distractor Analysis: Chief cells secrete pepsinogen (inactive precursor). Mucous neck cells secrete mucus. G-cells secrete gastrin, a hormone that stimulates acid secretion but does not directly supply HCl. Takeaway: Parietal cells also secrete intrinsic factor, essential for vitamin B12 absorption; their failure can lead to pernicious anemia.
Answer or skip previous question to unlock.
Q.7
Based on: WBCS Prelims 2009
Who conducted pioneering experiments on human digestion using a gastric fistula in a patient named Alexis St. Martin?
A.William Harvey
B.William Beaumont
C.Ivan Pavlov
D.Claude Bernard
Explanation
Why Correct: William Beaumont, an American army surgeon, studied digestion directly through a gastric fistula in patient Alexis St. Martin between 1822 and 1833. His work laid the foundation for modern gastric physiology. Distractor Analysis: William Harvey discovered the circulation of blood. Ivan Pavlov is known for classical conditioning and digestive reflexes in dogs. Claude Bernard contributed to pancreatic and liver function studies. Takeaway: Beaumont's experiments demonstrated that gastric juice contains hydrochloric acid and that digestion is primarily a chemical process.
Sign in to save progress
Sign in to Papersetters
Save your progress, unlock Smart Review, and track your performance.