Digestive System MCQ for RRB & SSC and other Competitive exams
1
Which of the following organs stores glycogen?
✓ Answer:
C
Liver
The liver stores excess glucose as glycogen (Glycogenesis). When blood sugar falls, the liver breaks glycogen back into glucose (Glycogenolysis) and releases it. This is regulated by Insulin (promotes storage) and Glucagon (promotes release).
2
Peptic ulcers are most commonly caused by which bacteria?
✓ Answer:
C
Helicobacter pylori
Helicobacter pylori (H. pylori) is a bacteria that can survive in the acidic stomach environment. It damages the mucus lining of the stomach, leading to Peptic Ulcers. This was a Nobel Prize-winning discovery (2005). H. pylori ulcers are treated with antibiotics + proton pump inhibitors.
3
Which part of the digestive system absorbs most nutrients?
✓ Answer:
C
Small Intestine
The small intestine is the primary site of nutrient absorption due to Villi and Microvilli that vastly increase its surface area. Glucose, amino acids, and fatty acids are absorbed here into the bloodstream.
4
HCl in the stomach is secreted by which cells?
✓ Answer:
C
Parietal (Oxyntic) Cells
Parietal (Oxyntic) Cells secrete HCl. Chief Cells secrete Pepsinogen. Goblet Cells secrete mucus. HCl creates the acidic environment needed to activate pepsin.
5
Which enzyme in pancreatic juice digests fats?
✓ Answer:
C
Lipase
Pancreatic Lipase digests fats (triglycerides) into fatty acids and glycerol. It works in the small intestine after bile has emulsified the fats. Trypsin digests proteins, amylase digests starch, and pepsin works only in the stomach.
6
Which sphincter controls the passage of food from the stomach to the small intestine?
✓ Answer:
C
Pyloric Sphincter
The Pyloric Sphincter is located at the junction of the stomach and duodenum. It regulates the flow of chyme into the small intestine. The Cardiac Sphincter (Lower Oesophageal Sphincter) prevents backflow of food from the stomach into the oesophagus.
7
Where is water mainly absorbed in the digestive system?
✓ Answer:
C
Large Intestine
While some water is absorbed in the small intestine, the majority of water reabsorption occurs in the Large Intestine (Colon). This is why diarrhoea (too little reabsorption) leads to dehydration and constipation (too much reabsorption) leads to hard stools.
8
The movement of food through the alimentary canal by wave-like contractions is called?
✓ Answer:
C
Peristalsis
Peristalsis is the rhythmic, wave-like muscular contraction that moves food along the entire digestive tract. It is involuntary and occurs throughout - from the oesophagus to the rectum.
9
Which digestive enzyme is secreted by the small intestine wall?
✓ Answer:
C
Enterokinase
Enterokinase (Enteropeptidase) is secreted by the cells of the duodenum wall. Its key function is to activate Trypsinogen into Trypsin. This is a cascade activation - Trypsin then activates other pancreatic enzymes like chymotrypsinogen and proelastase.
10
Which of the following is the correct function of Goblet cells?
✓ Answer:
C
Secrete mucus
Goblet cells are found throughout the digestive tract and secrete mucus that lubricates the passage of food and protects the gut lining. In the stomach, mucus protects against HCl. In the intestines, it aids smooth movement of food material.