Q.1. The enzyme enterokinase helps in conversion of 
(a) Caseinogen into casein
(b) Pepsinogen into pepsin
(c) Protein into polypeptides
(d) Trypsinogen into trypsin
Sol. Trypsinogen is present in inactive form in pancreatic juice. So enterokinase enzyme converts inactive trypsinogen to active trypsin. This in turn activates the other enzymes in the pancreatic juice.
Q.2. Identify the correct statement with reference to human digestive system. 
(a) Ileum is a highly coiled part
(b) Vermiform appendix arises from duodenum
(c) Ileum opens into small intestine
(d) Serosa is the innermost layer of the alimentary canal.
(a) Small intestine is distinguishable into three regions, a ‘U’ shaped duodenum, a long coiled middle portion jejunum and a highly coiled ileum.
(b) A narrow finger-like tubular projection, the vermiform appendix which is a vestigial organ, arises from the caecum.
(c) Ileum opens into the large intestine.
(d) The wall of alimentary canal possesses four layers from outer to inner namely serosa, muscularis, submucosa and mucosa. Serosa is the outermost layer and mucosa is the innermost layer.
Q.3. Goblet cells of alimentary canal are modified from: 
(b) Compound epithelial cells
(c) Squamous epithelial cells
(d) Columnar epithelial cells
Sol. Goblet cells are modified columnar epithelial cells. It is found in the lining of organs like respiratory tract and intestine,
Q.4. Match the following structures with their respective location in organs.
Select the correct option from the following: 
Sol. Crypts of Lieberkhn are present in small intestine, Glisson's capsule is present in liver. Islets of Langerhans constitutes the endocrine portion of pancreas. Brunner's glands are found in submucosa of duodenum.
So, the correct answer is '(A)-(iii), (B)-(iv), (C)-(i), (D)-(ii)'
Q.5. Identify the cells whose secretion protects the lining of the gastrointestinal tract from various enzymes. 
(a) Duodenal cells
(b) Chief cells
(c) Goblet cells
(d) Oxyntic cells
Goblet CellGoblet cells or mucous cells are present throughout the epithelium of gastric glands and secrete mucus, which protects the gastrointestinal lining from enzymatic action.
Q.6. Match the items given in Column I with those in Column II and choose the correct option. 
(a) A-iii, B-iv, C-ii, D-i
(b) A-iv, B-iii, C-i, D-ii
(c) A-iv, B-iii, C-ii, D-i
(d) A-iii, B-iv, C-i, D-ii
Q.7. Which of the following terms describes human dentition? 
(a) Thecodont, Diphyodont, Homodont
(b) Thecodont, Diphyodont, Heterodont
(c) Pleurodont, Monophyodont, Homodont
(d) Pleurodont, Diphyodont, Heterodont
Q.8. Which of the following gastric cells indirectly help in erythropoiesis? 
(a) Chief cells
(b) Mucous cells
(c) Goblet cells
(d) Parietal cells
Parietal or oxyntic cells secrete HC1 and Castle intrinsic factor. HC1 converts iron present in diet from ferric (Fe3+) to ferrous (Fe2+) form in which iron can be absorbed. Castle intrinsic factor is essential for (the absorption of vitamin B12. Iron, protein, vitamin B12, and folic acid arc essential for the formation of RBCs and haemoglobin, hence parietal cells indirectly help in erythropoiesis.
Q.9. Which cells of ‘Crypts of Lieberkuhn’ secrete antibacterial lysozyme? 
(a) Paneth cells
(b) Zymogen cells
(c) Kupffer cells
(d) Argentaffin cells
Paneth cells, present in the bottom of crypts of Lieberkuhn, are rich in zinc and contain acidophilic granules. There is evidence that these cells secrete antibacterial lysozyme. Zymogen cells or peptic cells are present in the stomach and secrete pepsinogen.
Kupffer cells are present in the liver. They are phagocytic in nature and engulf disease-causing microorganisms, dead cells, etc. Argentaffin cells, found in crypts of Lieberkuhn, synthesize hormone secretin and 5 - hydroxytryptamine.
Q.10. Which of the following options best represents the enzyme composition of pancreatic juice? 
(a) Amylase, Pepsin, Trypsinogen, Maltase
(b) Peptidase, Amylase, Pepsin, Rennin
(c) Lipase, Amylase, Trypsinogen, Procarboxypeptidase
(d) Amylase, Peptidase, Trypsinogen, Rennin
Sol. The pancreatic juice contains sodium bicarbonate, three proenzymes: trypsinogen, chymotrypsinogen, and procarboxypeptidase and some enzymes such as elastase, pancreatic a-amylase, DNase, RNase and pancreatic lipase. It helps in the digestion of starch, proteins, fats, and nucleic acids.
Q.11. A baby boy aged two years is admitted to playschool and passes through a dental check-up. The demist observed that the boy had twenty teeth. Which teeth were absent? 
Sol. Boy aged two years will have milk teeth of man include 8 incisors, 4 canines, 8 molars. Premolars are absent.
Q.12. Which hormones do stimulate the production of pancreatic juice and bicarbonate? (2016)
(a) Angiotensin and epinephrine
(b) Gastrin and insulin
(c) Cholecystokinin and secretin
(d) Insulin and glucagon
Cholecystokinin(CCK) and SecretinCholecystokinin pancreozymins (CCKPZ) is a hormone secreted from the small intestine. It stimulates the gall bladder to release bile and the pancreas to secrete and release digestive enzymes in the pancreatic juice. Hormone secretin is secreted from the duodenum and releases bicarbonates in the pancreatic juice. It also increases the secretion of bile and decreases gastric secretion and motility.
Q.13. In the stomach, gastric acid is secreted by the 
(a) Gastrin secreting cells
(b) Parietal cells
(c) Peptic cells
(d) Acidic cells
Sol. The main constituent of gastric acid is hydrochloric acid produced by parietal cells (also called oxyntic cells) in the stomach's gastric glands.
Q.14. Which of the following guards the opening of the hepatopancreatic duct into the duodenum? 
(a) Semilunar valve
(b) Ileocaecal valve
(c) Pyloric sphincter
(d) Sphincter of Oddi
Sol. The sphincter of Oddi (or hepatopancreatic sphincter) is a muscular valve that controls the flow of digestive juices (bile and pancreatic juice) through the ampulla of Vater into the second part of the duodenum.
Q.15. Which of the following statements is not correct? 
(a) Goblet cells are present in the mucosa of the intestine and secrete mucus.
(b) Oxyntic cells are present in the mucosa of the stomach and secrete HCl.
(c) Acini are present in the pancreas and secrete carboxypeptidase.
(d) Brunner's glands are present in the submucosa of the stomach and secrete pepsinogen.
Sol. Duodenum contains Brunner’s glands which secrete mucus and digestive juices.
Q.16. Gastric juice of infants contains: 
(a) Nuclease, pepsinogen, lipase
(b) Pepsinogen, lipase, rennin
(c) Amylase, rennin, pepsinogen
(d) Maltase, pepsinogen, rennin
Sol. Gastric juice of infants contains pepsinogen, lipase, and rennin. Gastric juice does not contain amylase, maltase & nuclease.
Q.17. The primary dentition in human differs from permanent dentition in not having one of the following types of teeth: 
The premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. There are two premolars per quadrant in the permanent set of teeth in humans, making eight premolars total in the mouth. The dental formula for milk teeth is 2102/2102 so premolars are absent in the primary dentition.
Q.18. The initial step in the digestion of milk in humans is carried out by 
Sol. Rennin (also called chymosin) is an enzyme that occurs in gastric juice and is a constituent of rennet. It coagulates milk by converting caseinogen to casein. The initial step in the digestion of milk in humans is carried out by rennin.
Q.19. Fructose is absorbed into the blood through mucosa cells of the intestine by the process called: 
(a) Active transport
(b) Facilitated transport
(c) Simple diffusion
(d) Co-transport mechanism
Sol. Facilitated transport is a form of passive transport in which materials are moved across the plasma membrane by a transport protein down their concentration gradient. Hence, it does not require energy.