Digestive System MCQ for RRB & SSC and other Competitive exams
41
Where does digestion of food begin in the human body?
✓ Answer:
C
Mouth
Digestion begins in the mouth (buccal cavity). Salivary glands secrete saliva containing Salivary Amylase (Ptyalin) that breaks starch into maltose. Teeth perform mechanical breakdown. Both mechanical and chemical digestion start here.
42
Which of the following diseases is caused by infection of the liver?
✓ Answer:
B
Hepatitis
Hepatitis is the inflammation of the liver, caused by Hepatitis viruses (A, B, C, D, E). Hepatitis B and C can become chronic and lead to liver cirrhosis or cancer. Hepatitis A and E spread through contaminated water/food. Typhoid and cholera affect the intestines.
43
Which gland produces the maximum amount of digestive enzymes?
✓ Answer:
C
Pancreas
The Pancreas produces the most comprehensive set of digestive enzymes - Pancreatic Amylase (carbs), Pancreatic Lipase (fats), Trypsin and Chymotrypsin (proteins), Nucleases (nucleic acids). It is often called the principal digestive gland.
44
What is the name of the enzyme that digests nucleic acids (DNA and RNA)?
✓ Answer:
B
Nuclease
Nucleases (DNase and RNase) are enzymes present in pancreatic juice that digest nucleic acids (DNA and RNA) into nucleotides. These are then further broken down by intestinal enzymes into nitrogenous bases, sugars, and phosphates for absorption.
45
Which part of the digestive system does NOT perform digestion?
✓ Answer:
C
Oesophagus
The Oesophagus is a muscular tube that simply transports food from the mouth to the stomach via peristalsis. It has no digestive glands and secretes no digestive enzymes. Its only secretion is mucus to lubricate the food passage.
46
Which part of the small intestine receives bile and pancreatic juice?
✓ Answer:
C
Duodenum
The Duodenum is the first and shortest part of the small intestine. It receives bile from the liver (via gall bladder) and pancreatic juice from the pancreas through the hepatopancreatic duct. This is where most chemical digestion begins intensively.
47
Which digestive juice contains NO enzyme?
✓ Answer:
B
Bile
Bile has no digestive enzyme. It only helps in emulsification of fats - breaking fat into smaller droplets so lipase can act on them. It also neutralizes acidic chyme from the stomach.
48
Which of the following correctly describes the function of the Ileocaecal valve?
✓ Answer:
B
Prevents backflow of faeces from large intestine to small intestine
The Ileocaecal Valve is located at the junction of the ileum (small intestine) and caecum (large intestine). It allows one-way passage of digested material from the small intestine into the large intestine and prevents backflow of faecal matter into the small intestine.
49
Which enzyme is present in saliva?
✓ Answer:
C
Salivary Amylase
Salivary Amylase (Ptyalin) is the enzyme found in saliva. It acts on starch and converts it into maltose. It works best in a slightly alkaline/neutral pH. Once food reaches the acidic stomach, salivary amylase becomes inactive.
50
Which of the following is NOT a function of the liver?
✓ Answer:
D
Production of insulin
Insulin is produced by the Pancreas (Beta cells of Islets of Langerhans), NOT the liver. The liver produces bile, detoxifies harmful substances, stores glycogen (energy reserve), and synthesizes plasma proteins (fibrinogen, albumin).