The Class 11 chapter Digestion and Absorption deals with the anatomy of the digestive system and the processes of digestion and absorption. Here are some important MCQs from this chapter that will help NEET aspirants in last-minute revisions.

1. The small projections on the upper surface of the tongue, some of which have taste buds are called ⸻

1. Lingual frenulum
2. Papillae
3. Uvula
4. Palate

Answer: b. Papillae

Discussion: The small projections on the upper surface of the tongue are called papillae. Some papillae have taste buds on them. The different types of papillae are:

• Circumvallate papillae
• Fungiform papillae
• Filiform papillae
• Foliate papillae

2. The specialised structure which prevents the entry of food into the respiratory tract during swallowing is

1. Uvula
2. Epiglottis
3. Pharynx
4. Larynx

Answer: b. Epiglottis

Discussion: Pharynx is the common passage for food and air. Posteriorly, the pharynx opens into the oesophagus (food pipe) and anteriorly into the trachea (windpipe). Larynx is the voice box. It consists of the epiglottis, glottis and various other cartilages. Epiglottis is a cartilaginous flap that specifically prevents the entry of food into the glottis (opening of the larynx) during swallowing.

3. Dental formula for milk teeth is

1. 2,1,2,3/2,1,2,3
2. 2,1,0,2/2,1,0,2
3. 2,1,2,2/2,1,2,2
4. 3,1,4,3/3,1,4,3

Answer: b. 2,1,0,2/2,1,0,2

Discussion: The dental formula includes incisors (I), canine (C), premolars (Pm) and molars (M). The formula includes one side of the jaw, and the number of teeth in each jaw is the same for humans.

Milk teeth – Dental formula

I 2/2, C 1/1, Pm 0/0, M 2/2 = 10 (10 ×2 = 20 teeth)

Permanent teeth – dental formula

I 2/2, C 1/1, Pm 2/2, M 3/3 = 16 (16×2 = 32 teeth)

4. Which of the following is a micronutrient?

1. Fats
2. Carbohydrates
3. Vitamins
4. Proteins

Answer: c. Vitamins

Discussion: Nutrients can be classified into:

1. Macronutrients – carbohydrates, proteins and fats
2. Micronutrients – vitamins and minerals

5. Match the following

1. A-3, B-2, C-1, D-4
2. A-3, B-1, C-4, D-2
3. A-3, B-4, C-1, D-2
4. A-2, B-4, C-1, D-3

Answer: c. A-3, B-4, C-1, D-2

Discussion:

1. Enamel is the outermost layer of the teeth and it is the hardest substance in the body.
2. Dentine joins enamel and pulp.
3. Cement helps in joining the teeth in the socket.
4. Pulp cavity consists of connective tissue, nerve fibres, lymph and blood vessels.

6. Match the following

1. A-1, B-2, C-3
2. A-2, B-3, C-1
3. A-3, B-2, C-1
4. A-2, B-1, C-3

Answer: b. A-2, B-3, C-1

Discussion: The pharynx can be subdivided into 3 parts –

1. Nasopharynx – It is the upper part of the pharynx and is connected to the nasal cavity.
2. Oropharynx – It is the middle region of the pharynx and is connected to the mouth.
3. Laryngopharynx – It is the bottom part of the pharynx and it guides the food and air to the oesophagus and the larynx respectively.

7. Digestion of food begins in the

1. Stomach
2. Small intestine
3. Mouth
4. Large intestine

Answer: c. Mouth

Discussion: Digestion of food begins in the mouth with the breakdown of starch into disaccharides called maltose. The enzyme, salivary amylase or ptyalin, secreted by salivary glands in the mouth, is responsible for this partial breakdown of starch.

The digestion process continues in the stomach and completes in the small intestine due to the action of various enzymes. The large intestine is responsible for the absorption of water and other important minerals.

See more:Flashcards for NEET Biology – Digestion and Absorption

8. Match the following

1. 1-A, 2-B, 3-D, 4-C
2. 1-C, 2-D, 3-B, 4-A
3. 1-D, 2-A, 3-B, 4-C
4. 1-B, 2-A, 3-D, 4-C

Answer: d. 1-B, 2-A, 3-D, 4-C

Discussion: Polysaccharides are acted upon by carbohydrases and broken down into simpler substances like monosaccharides. Meanwhile, proteins are acted upon by proteases and broken down into simpler substances like amino acids.

Lipids are acted upon by lipases and broken down into simpler substances like fatty acids and glycerol. Likewise, nucleic acids are acted upon by nucleases and broken down into simpler substances like sugars and nitrogenous bases.

9. Assertion – The food digested by the stomach is highly acidic. When it passes through the duodenum it becomes nearly neutral.

Reason – Brunner’s glands in the duodenum produce mucin which is alkaline.

1. Both the assertion and reason are true and the reason is the correct explanation of the assertion
2. Both the assertion and reason are true but the reason is not the correct explanation of the assertion
3. The assertion is true but the reason is false
4. Both assertion and reason are false

Answer: a. Both the assertion and reason are true and the reason is the correct explanation of the assertion.

Discussion: HCl present in the stomach makes pH of the gut acidic which helps in the activation of pepsinogen and its conversion into pepsin. Brunner’s glands are located in the submucosa of the duodenum (initial region of the small intestine). They secrete an alkaline fluid containing mucin which protects the mucosa from the acidic stomach contents entering the duodenum. It, therefore, makes the environment in the duodenum nearly neutral.

10. Identify the ducts in the following figure

1. A – Common Bile Duct, B – Pancreatic Duct, C – Cystic Duct, D – Hepatopancreatic Duct
2. A – Cystic Duct, B – Common Bile Duct, C – Pancreatic Duct, D – Hepatopancreatic Duct
3. A – Common Bile Duct, B – Cystic Duct, C – Pancreatic Duct, D – Hepatopancreatic Duct
4. A – Cystic Duct, B – Pancreatic Duct, C – Common Bile Duct, D – Hepatopancreatic Duct

Answer: b. A – Cystic Duct, B – Common Bile Duct, C – Pancreatic Duct, D – Hepatopancreatic Duct

Discussion:

11. Which digestive organ is also called a heterocrine gland?

1. Liver
2. Pancreas
3. Large intestine
4. Jejunum

Answer: b. Pancreas

Discussion: A heterocrine gland functions as both exocrine (where the secretions are carried by ducts to specific target organs) as well as an endocrine gland (where secretions are released directly into the bloodstream). Example – Pancreas.

Pancreas as an endocrine gland secretes two hormones – glucagon and insulin directly into the bloodstream to control blood sugar levels. As an exocrine gland, the pancreas secretes enzymes like trypsinogen into the duodenum via the pancreatic duct.

Also Check:Pancreas: Function in Human Body

12. Trypsin, chymotrypsin and carboxypeptidase are examples of

1. Lipases
2. Carbohydrases
3. Proteases
4. Nucleases

Answer: c. Proteases

Discussion: Lipases, carbohydrases and proteases play an important role in digestion. Trypsin, carboxypeptidase and chymotrypsin are different proteases that break down proteins into smaller polypeptides and peptides.

Lipases are a set of enzymes that break triglycerides (fats) into fatty acids and glycerol. Carbohydrases are a set of enzymes that convert bigger carbohydrates into smaller ones. Amylase, maltase and sucrase are a few examples of carbohydrases.

13. Which of the following is correct with respect to succus entericus?

1. It is secreted by cells in the mucosa of the small intestine
2. It is also known as intestinal juice
3. It contains digestive enzymes
4. All the above

Answer: d. All the above

Discussion: The secretion of the cells in the brush border of the mucosa along with the secretions of the goblet cells in the small intestine constitutes succus entericus. Succus entericus is also known as intestinal juice. Intestinal juice contains digestive enzymes, hormones, mucus, substances to neutralise HCl coming from the stomach, etc.

14. Which of the following is important for the emulsification of fats?

1. Trypsin
2. Bile salts
3. Pancreatic lipase
4. Both b and c

Answer: b. Bile salts

Discussion: Bile breaks down large drops of fat into a fine suspension of smaller droplets called micelles. This process is known as emulsification. Bile contains a large quantity of bile salts, which are responsible for the emulsification process. After emulsification, emulsified fats begin to get broken down into diglycerides and monoglycerides by the action of pancreatic lipase. Pancreatic lipase itself does not take part in the emulsification of fats. Trypsin is a proteolytic enzyme and hence catalyses the breakdown of protein digestion products coming from the stomach.

15. Gastrointestinal secretions and local blood flow are mainly controlled by

1. Auerbach’s plexus
2. Myenteric plexus
3. Submucosal plexus
4. Both b and c

Answer: c. Submucosal plexus

Discussion: A plexus is a branching network of vessels or nerves. An inner plexus called the submucosal plexus or Meissner’s plexus lies in the submucosa. The submucosal plexus controls mainly gastrointestinal secretion and local blood flow. The myenteric plexus or Auerbach’s plexus is located in the muscularis layer. The myenteric plexus controls mainly the gastrointestinal movement.

16. Lacteals are present in the ⸻

1. Large intestine
2. Stomach
3. Small intestine
4. Mouth

Answer: c. Small intestine

Discussion: Lacteals are present in the small intestine. The mucosa of the small intestine consists of a large number of finger-like projections called villi and each villus is lined by columnar epithelium. Underneath the epithelial layer, a lymphatic vessel called lacteal is present that opens up to the lymphatic system. They help in the absorption of fatty acids.

17. Small intestine is divided into the following parts except

1. Ileum
2. Ischium
3. Jejunum
4. Duodenum

Answer: b. Ischium

Discussion: Small intestine can be divided into three parts –

1. Duodenum – it is the C-shaped structure of the small intestine
2. Jejunum – duodenum opens into the jejunum, which is the middle part of the small intestine.
3. Ileum – it is the longest part of the small intestine.

The jejunum opens into the ileum and the ileum further opens into the large intestine. Both ileum and jejunum are coiled. But comparatively, the ileum is more coiled than the jejunum.

But ischium is a part of the hip bone. It is not related to the alimentary canal.

18. Which of the following hormones is secreted by the gastric glands?

1. Secretin
2. Cholecystokinin
3. Gastrin
4. Duocrinin

Answer: c. Gastrin

Discussion:

19. A boy was interested in calculating the number of calories in his diet. He ate the following items in the diet.

What is the total calories he is likely to have consumed (kcal/g)?

1. 161
2. 146
3. 122
4. 134

Answer: d. 134

Discussion: The physiological calorific value is the actual amount of energy liberated by the consumption of 1 gram of carbohydrates, proteins and fats. The physiological calorific values for different nutrients are provided below.

Thus the total calories consumed by the boy in his diet can be calculated as follows –

• Calories from carbohydrates = 6 × 4 = 24 kcal/g
• Calories from pure ghee = 8 × 9 = 72 kcal/g
• Calories from lignin = 0 kcal/g
• Calories from albumin = 5 × 4 = 20 kcal/g
• Calories from vegetable ghee = 2 ×9 = 18 kcal/g

Total calories = sum of the calories from all sources

24+72+20+18 = 134 kcal/g

20. Match the following

1. A-4, B-3, C-1, D-2
2. A-3, B-2, C-1, D-4
3. A-1, B-3, C-2, D-4
4. A-4, B-2, C-1, D-3

Answer: a. A-4, B-3, C-1, D-2

Discussion: Below mentioned are some digestive disorders and their correct description

Explore important questions from the next chapter with regards to NEET, only at BYJU’S. Do check here for the important notes on Digestion and Absorption.

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