NEET Biology Digestion and Absorption MCQs Set 16

Answer: (c) 20

Explanation:
1. Milk teeth (20 in number) are replaced once by permanent teeth, so 20 teeth grow twice in life.

Teacher's Note:
1. Molars never have a milk set.
2. Twenty milk teeth are replaced.

Answer: (b) Incisor

Explanation:
1. Incisors have sharp edges and are used for cutting food.

Teacher's Note:
1. Canines tear, molars crush.
2. Incisors cut.

Answer: (a) Crushing

Explanation:
1. Premolars and molars have broad surfaces with cusps, so they are modified for crushing and grinding food.

Teacher's Note:
1. Canines are for tearing.
2. They crush food.

Answer: (a) Odontoblast

Explanation:
1. The pulp cavity is lined by odontoblasts, which form dentine.

Teacher's Note:
1. Ameloblasts form enamel.
2. Odontoblasts line the pulp cavity.

Answer: (b) Rugae

Explanation:
1. The stomach lining has longitudinal folds called rugae that allow the stomach to expand.

Teacher's Note:
1. Villi belong to the small intestine.
2. Rugae are stomach folds.

Answer: (a) liver

Explanation:
1. Glisson's capsule is the connective tissue covering of the liver and its lobules.

Teacher's Note:
1. Hepatic lobules are the functional units.
2. Glisson's capsule belongs to liver.

Answer: (a) heterodont, thecodont, diphyodont

Explanation:
1. Teeth of different kinds are heterodont, placed in sockets is thecodont, and two sets in life is diphyodont.

Teacher's Note:
1. Humans show all three.
2. Different, socketed, two sets.

Answer: (c) iii i ii v iv

Explanation:
1. Hepatic lobule is covered by Glisson's capsule, Brunner's glands are submucosal, crypts of Lieberkuhn lie at villi bases, the sphincter of Oddi guards the hepatopancreatic duct and the cystic duct drains the gall bladder.

Teacher's Note:
1. Match each structure to its location.
2. This pairing gives option 3.

Answer: (a) below right lobe of liver

Explanation:
1. The gall bladder is a pear-shaped sac lying under the right lobe of the liver.

Teacher's Note:
1. It stores bile.
2. Gall bladder lies below the right lobe.

Answer: (b) sphincter of oddi

Explanation:
1. The sphincter of Oddi guards the opening of the hepatopancreatic duct and controls release of bile and pancreatic juice into the duodenum.

Teacher's Note:
1. The pyloric sphincter guards the stomach exit.
2. Oddi controls bile release.

Answer: (a) i = 2/2, c = 1/1, pm = 0/0, m = 2/2

Explanation:
1. A child of 5-6 years has only milk teeth with formula i 2/2, c 1/1, pm 0/0, m 2/2 which is 20 teeth.

Teacher's Note:
1. Milk teeth have no premolars.
2. Milk teeth have no premolars.

Answer: (b) Ptyalin

Explanation:
1. Saliva contains salivary amylase, also called ptyalin, which starts starch digestion.

Teacher's Note:
1. Maltase and invertase are intestinal.
2. Ptyalin is the salivary enzyme.

Answer: (d) Duodenum

Explanation:
1. The duodenum receives bile, pancreatic and intestinal juice, so maximum digestion takes place there.

Teacher's Note:
1. Jejunum is the main site of absorption.
2. Most digestion occurs in the duodenum.

Answer: (b) Salts

Explanation:
1. Bile salts emulsify fats into fine droplets so lipase can act; without them fat digestion is difficult.

Teacher's Note:
1. Pigments give colour only.
2. Bile salts help fat digestion.

Answer: (a) Duodenum

Explanation:
1. Pancreatic juice flows through the pancreatic duct into the duodenum.

Teacher's Note:
1. It joins the bile duct first.
2. It enters the duodenum.

Answer: (a) Bile juice, pancreatic juice and intestinal juice

Explanation:
1. Bile, pancreatic juice and intestinal juice (succus entericus) mix with food in the small intestine.

Teacher's Note:
1. Gastric juice acts in the stomach.
2. Three juices act in the small intestine.

Answer: (d) Enterogastrin

Explanation:
1. Enterogastrone, released from the intestine, inhibits gastric secretion and motility, whereas gastrin stimulates it.

Teacher's Note:
1. Secretin mainly acts on the pancreas.
2. Enterogastrone inhibits gastric juice.

Answer: (b) Lipase

Explanation:
1. Lipase hydrolyses emulsified fats into fatty acids and glycerol.

Teacher's Note:
1. Amylase acts on starch.
2. Lipase digests fats.

Answer: (a) Rennin

Explanation:
1. Secretin, calcitonin and oxytocin are hormones, but rennin is an enzyme.

Teacher's Note:
1. Rennin curdles milk.
2. Rennin is an enzyme.

Answer: (d) Enterogastrin

Explanation:
1. Enterogastrone is a hormone. Enterokinase, amylase and trypsin are enzymes.

Teacher's Note:
1. Hormones regulate secretion.
2. Enterogastrone is not an enzyme.

Answer: (d) Pancreatic juice

Explanation:
1. Secretin stimulates the pancreas to release bicarbonate rich pancreatic juice.

Teacher's Note:
1. CCK causes enzyme release and gall bladder contraction.
2. Secretin acts on pancreatic juice.

Answer: (c) Acid in chyme

Explanation:
1. Acidic chyme entering the duodenum stimulates cells of the intestinal wall to secrete secretin.

Teacher's Note:
1. Fatty food causes CCK release.
2. Acid in chyme triggers secretin.

Answer: (b) Triglycerides

Explanation:
1. Pancreatic lipase breaks down triglycerides into fatty acids and monoglycerides.

Teacher's Note:
1. It needs emulsified fat.
2. Lipase acts on triglycerides.

Answer: (c) Carbohydrates

Explanation:
1. Excess carbohydrate in the diet is converted to fat and stored in adipose tissue.

Teacher's Note:
1. Vitamins and minerals are not energy storage.
2. Extra carbohydrate becomes fat.

Answer: (b) Liver

Explanation:
1. Bile is made by the hepatic cells of the liver and only stored in the gall bladder.

Teacher's Note:
1. It is concentrated in the gall bladder.
2. Liver forms bile.

Answer: (c) Enterokinase

Explanation:
1. Enterokinase from the intestinal mucosa converts inactive trypsinogen to active trypsin.

Teacher's Note:
1. Trypsin then activates other zymogens.
2. Enterokinase activates trypsinogen.

Answer: (d) Cobalamine

Explanation:
1. Castle's intrinsic factor from the stomach is needed for absorption of vitamin B12 (cobalamin).

Teacher's Note:
1. Lack causes pernicious anaemia.
2. Intrinsic factor helps B12.