60. In which carbohydrate form is energy chiefly stored in human liver and muscles?
[RRB NTPC Graduate CBT-I (25 Mar 2026, Shift 2)]
- (a) Glycogen
- (b) Sucrose
- (c) Cellulose
- (d) Starch
Answer: (a) Glycogen
Explanation: Glycogen is a highly branched glucose polymer synthesised and stored in liver and skeletal muscles. Liver glycogen helps regulate blood glucose between meals, whereas muscle glycogen supplies fuel for local muscular activity. Humans do not store energy as plant starch.
59. The optimal pH values for pepsin and trypsin are closest to which pair?
[UPSC NDA-II (2025)]
- (a) 2.0 and 7.9, respectively
- (b) 4.5 and 3.5, respectively
- (c) 9.5 and 4.5, respectively
- (d) 7.0 and 8.0, respectively
Answer: (a) 2.0 and 7.9, respectively
Explanation: Pepsin acts in the acidic stomach and has its optimum near pH 2. Trypsin is a pancreatic enzyme working in the relatively alkaline small intestine, near pH 8. Their contrasting requirements reflect different digestive environments.
58. Which of these is the largest gland of the human body?
[MAHA TET Paper-II, Mathematics and Science (23 Nov 2025)]
- (a) Pancreas
- (b) Liver
- (c) Adipose tissue
- (d) Adrenal gland
Answer: (b) Liver
Explanation: The liver is the largest gland and a major digestive accessory organ. It produces bile, processes absorbed nutrients, and stores glycogen. The pancreas is a mixed gland but is much smaller; adipose tissue is not the largest digestive gland.
57. What can happen to carbohydrates consumed in excess of energy needs?
[RRB NTPC Undergraduate CBT-I (19 Aug 2025, Shift 2)]
- (a) They must become proteins
- (b) They are stored as amino acids
- (c) They can be converted into fat and stored
- (d) They are all excreted immediately
Answer: (c) They can be converted into fat and stored
Explanation: Excess glucose can first replenish glycogen stores. When energy intake continues to exceed requirements, carbohydrate carbon may be converted into fatty acids through lipogenesis and stored as triglycerides. Thus, it need not be eliminated immediately in urine.
56. Which is the longest segment of the alimentary canal?
[SSC CGL Tier-I (23 Sep 2024, Shift 3)]
- (a) Stomach
- (b) Large intestine
- (c) Oesophagus
- (d) Small intestine
Answer: (d) Small intestine
Explanation: The small intestine is longer than the stomach, large intestine, and oesophagus. Its duodenum, jejunum, and ileum support extensive enzymatic digestion and nutrient absorption. Its many coils allow several metres of intestine to fit inside the abdominal cavity.
55. Which glands assist food digestion inside the stomach?
[SSC Selection Post, Higher Secondary (21 Jun 2024, Shift 2)]
- (a) Gastric glands
- (b) Pituitary gland
- (c) Thyroid gland
- (d) Pineal gland
Answer: (a) Gastric glands
Explanation: Gastric glands embedded in the stomach mucosa release hydrochloric acid, pepsinogen, and protective mucus through specialised cell types. Their secretions contribute to protein digestion and defend the gastric wall. The other glands listed primarily have endocrine functions.
54. Which pancreatic serine protease is a globular protein found in vertebrate digestion?
[SSC CHSL Tier-I (08 Jul 2024, Shift 3)]
- (a) Trypsin
- (b) Amylase
- (c) Lipase
- (d) Pepsin
Answer: (a) Trypsin
Explanation: Trypsin is released from the pancreas as trypsinogen and activated within the small intestine. As a serine protease, it breaks peptide bonds in dietary proteins. Amylase acts on starch, lipase on lipids, and pepsin functions mainly in the stomach.
53. Which enzyme is essential for the chemical digestion of fats?
[SSC JE Civil (06 Jun 2024, Shift 3)]
- (a) Lipase
- (b) Zymase
- (c) Trypsin
- (d) Invertase
Answer: (a) Lipase
Explanation: Lipase hydrolyses triglycerides into absorbable lipid products, chiefly fatty acids and monoglycerides. Pancreatic lipase is especially important in the small intestine, where bile salts have already dispersed fat droplets to increase the area available for enzyme action.
52. What is the pancreatic contribution to human digestion?
[UPSC NDA-I (2024)]
- (a) Secretion of surfactants alone
- (b) Storage and regulated release of bile
- (c) Secretion of lipase, amylase, and proteases
- (d) Production of gastric hydrochloric acid
Answer: (c) Secretion of lipase, amylase, and proteases
Explanation: The exocrine pancreas sends digestive enzymes through ducts into the duodenum. Amylase acts on carbohydrates, lipase on fats, and proteases such as trypsin on proteins. Bile is made by the liver and stored in the gallbladder.
51. What does lipase do during the process of digestion?
[SSC CGL Tier-I (20 Jul 2023, Shift 1)]
- (a) Breaks down roughage
- (b) Breaks down emulsified fats
- (c) Produces intestinal secretions
- (d) Digests proteins
Answer: (b) Breaks down emulsified fats
Explanation: Lipase is a fat-digesting enzyme. Bile salts first disperse large fat masses into small droplets, and pancreatic lipase then hydrolyses triglyceride molecules. This permits intestinal absorption of lipid digestion products and fat-soluble substances.
