NCERT Exemplar Class 11 Biology Solutions Chapter 16 Digestion and Absorption

NCERT Exemplar Class 11th Biology Solution Chapter 16 Digestion And Absorption- Multiple Choice Questions

By solving different forms of questions, students gain more clarity about the concepts and how the questions will come in the exam. Given below are various types of questions that students need to practice. Practicing the Digestion and Absorption Class 11 NCERT Exemplar improves learning.

Question:1

Select what is not true of intestinal villi among the following.

(a) They possess microvilli
(b) They increase the surface area
(c) They are supplied with capillaries and the lacteal vessels
(d) They only participate in the digestion of fats

Answer:

The answer is option (d). They only participate in the digestion of fats.

Question:2

Hepato-pancreatic duct opens into the duodenum and carries
(a) Bile (b) Pancreatic juice (c) Both bile and pancreatic juice (d) Saliva

Answer:

The answer is option (c) Hepato-pancreatic duct opens into the duodenum and carries both bile and pancreatic juice.

Question:3

One of the following is not a common disorder associated with the digestive system.m

(a) Tetanus (b) Diarrhoea (c) Jaundice (d) Dysentery

Answer:

The answer is option (a). Tetanus is not a common disorder associated with the digestive system.

Question:4

A gland not associated with the alimentary canal is
(a) Pancreas (b) Adrenal (c) Liver (d) Salivary glands

Answer:

The answer is option (b). A gland not associated with the alimentary canal is the adrenal (this is the endocrine gland).

Question:5

Match the two columns and select the correct one among the options given

Options:

(a) A—(ii), B—(i), C—(v), D—(iii), E—(iv)

(b) A—(iv), B—(i), C—(v), D—(ii), E—(iii)

(c) A—(i), B—(ii), C—(iii), D—(iv), E—(v)

(d) A—(i), B—(iii), C—(ii), D—(iv), E-(v)

Answer:

The answer is option (b) A—(iv), B—(i), C—(v), D—(ii), E—(iii)

Question:6

Match the two columns and select the right one among the options given

(a) A—(i), B—(ii), C—(iii), D—(iv)

(b) A—(iv), B—(iii), C—(ii), D—(i)

(c) A—(iii), B—(i), C—(iv), D—(ii)

(d) A—(ii), B—(iv), C—(i), D—(iii)

Answer:

The answer is option (c) A—(iii), B—(i), C—(iv), D—(ii)

Question:7

Match the enzymes with their respective substrates and choose the right one among the options given.

Options:

(a) A—(ii), B—(iii), C—(i), D—(iv)

(b) A—(iii), B—(iv), C—(ii), D—(i)

(c) A—(iii), B—(i), C—(iv), D—(ii)

(d) A—(ii), B—(iii), C—(iv), D—(i)

Answer:

The answer is option (d) A—(ii), B—(iii), C—(iv), D—(i)

Question:8

The dental Formula for human beings is
a. 3223/3223

b. 2123/2123

c.1232/1232

d. 2233/2233

Answer:

b. 2123/2123

Question:9

The liver is the largest gland and is associated with several functions. Choose one that is not correct
(a) Metabolism of carbohydrate
(b) Digestion of fat
(c) Formation of bile
(d) Secretion of a hormone called gastrin

Answer:

The answer is option (d), secretion of a hormone called gastrin, as the liver performs all the other functions specified herein.

Question:10

Mark the right statement among the following
(a) Trypsinogen is an inactive enzyme
(b) Trypsinogen is secreted by the intestinal mucosa
(c) Enterokinase is secreted by the pancreas
(d) Bile contains trypsin

Answer:

The answer is option (a). Trypsinogen is an inactive enzyme.

Access the NCERT Exemplar Biology Solutions Digestion And Absorption- Very Short Answer Questions:

Question:1

The food mixes thoroughly with the acidic gastric juice of the stomach by the churning movements of its muscular wall. What do we call the food then?

Answer:

The food is then called chyme.

Question:2

Trypsinogen is an inactive enzyme of pancreatic juice. It is activated by an enzyme, enterokinase. Which tissue/ cells secrete this enzyme? How is it activated?

Answer:

The internal mucosa secretes trypsinogen. The enzyme enterokinase activates inactive trypsinogen into active trypsin.

Question:3

In which part of the alimentary canal does the absorption of water, simple sugars, and alcohol take place?

Answer:

The small intestine (duodenum and jejunum) is the major site for absorption of water and simple sugars, while alcohol is absorbed mainly in the stomach.

Question:4

Name the enzymes involved in the breakdown of nucleotides into sugars and bases.

Answer:

The enzymes involved in the breakdown of nucleotides into sugars and bases are nucleotidases and nucleosidases.

Question:5

Define digestion in one sentence.

Answer:

Digestion can be defined as the conversion of complex food substances into simpler, absorbable forms.

Question:6

What do we call the type of teeth attached to jawbones, in which each tooth is embedded in a socket of the jawbone

Answer:

The type of tooth attachment is known as Thecodont.

Question:7

The stomach is located in the upper-left portion of the abdominal cavity and has three major parts. Name these three parts.

Answer:

The three major parts include:

(a) Cardiac (b) Fundus (c) Pylorus

Question:8

Does the gall bladder make bile?

Answer:

No. The bile juice is produced by the liver.

Question:9

Correct the following statements by deleting one of the entries (given in bold).

(a) Goblet cells are located in the intestinal mucosal epithelium and secrete
chymotrypsin/mucus.

(b) Fats are broken down into di- and monoglycerides with the help of
amylase/lipases.

(c) Gastric glands of the stomach mucosa have oxyntic cells/ chief cells, which
secrete HCI.

(d) Saliva contains enzymes that digest
starch/protein.

Answer:

(a) Mucus

(b) Lipase

(c) Oxyntic cells.

(d) Starch.

Find the NCERT Exemplar Class 11th Biology Solution Chapter 16- Short Answer Type Questions

Question:1

What is the pancreas? Mention the major secretions of the pancreas that are helpful for digestion.

Answer:

The pancreas is a compound gland, i.e., both endocrine and exocrine glands. It is situated between the limbs of the U-shaped duodenum. It is a mixed gland since it contains both exocrine and endocrine parts. The exocrine portion of this gland secretes the pancreatic juice released in the duodenum and contains digestive enzymes. The digestive enzyme is alkaline and neutralizes the acid present in the food coming from the stomach into the duodenum. Whereas the endocrine portion of this gland secretes hormones: insulin and glucagon, which help maintain the level of sugar in the blood.

Question:2

Name the part of the alimentary canal where major absorption of digested food takes place. What are the absorbed forms of different kinds of food materials?

Answer:

The part of the alimentary canal where major absorption of digested food takes place is the small intestine. Carbohydrate is absorbed in glucose form, Proteins are absorbed in the form of amino acids, whereas fats are absorbed in the form of fatty acids and glycerol.

Question:3

List the organs of the human alimentary canal and name the major digestive glands with their location.

Answer:

The organs present in the human alimentary canal include the mouth, Oesophagus, Stomach, Small Intestine, Large Intestine, and Rectum

The major digestive glands are:

(a) Salivary gland: Mouth, (b) Gastric glands: Stomach, (c) Liver: adjacent to the stomach, (d) Pancreas: Below the stomach.

Question:4

What is the role of the gallbladder? What may happen if it stops functioning or is removed?

Answer:

The role of the gall bladder is to store bile juice secreted by the liver and release it as and when required in the duodenum.

In case the gall bladder stops functioning or is removed, bile directly flows into the small intestine, but it is less concentrated. Fat digestion may become less efficient, especially after fatty meals, though the body gradually adapts.

Question:5

Correct the statement given below by the right option shown in the bracket against them.

(a) Absorption of amino acids and glycerol takes place in the___.
(small intestine/ large intestine)

(b) The faeces in the rectum initiate a __reflex causing an urge for its removal.
(neural /hormonal)

(c) Skin and eyes turn yellow in__ infection.
(liver /stomach)

(d) Rennin is a proteolytic enzyme found in gastric juice in__
(infants/adults).

(e) Pancreatic juice and bile are released through.
(intestine-pancreatic/ hepatopancreatic duct)

(f) Dipeptides, disaccharides, and glycerides are broken down into simple substances in the region of ___small intestine.
(jejunum/ duodenum).

Answer:

(a) Small intestine

(b) Neural

(c) Liver

(d) Infants

(e) Hepato-pancreatic duct

(f) Duodenum

Question:6

What are the three major types of cells found in the gastric glands? Name their secretions.

Answer:

The major types of cells in gastric glands, along with their secretion, are:

(A) Mucous neck cells secrete mucus

(B) Peptic or chief cells secrete Pepsinogen, Prorennin

(C) Parietal or oxyntic cells secrete HCL and Intrinsic Factor.

Question:7

How is the intestinal mucosa protected from the acidic food entering from the stomach?

Answer:

The intestinal mucosa is protected from the acidic chyme by the secretion of mucus and bicarbonates from Brunner’s glands and goblet cells, which neutralize the acidity and prevent damage to the intestinal lining.

Question:8

How are the activities of the gastrointestinal tract regulated?

Answer:

Activities of the gastrointestinal tract are under neural and hormonal control for the proper coordination of different parts:

(i) The sight, smell, and/or the presence of food in the oral cavity can stimulate the secretion of saliva.

(ii) Similarly, gastric and intestinal secretions are also stimulated by neural signals.

(iii) The muscular activities of different parts of the alimentary canal can also be moderated by neural mechanisms (both local and through the CNS.

(iv) Hormonal control of the secretion of digestive juices is carried out by local hormones produced by the gastric and intestinal mucosa.

Question:9

Distinguish between constipation and indigestion. Mention their major causes.

Answer:

Question:10

Describe the enzymatic action on fats in the duodenum.

Answer:

In the duodenum, bile salts secreted by the liver emulsify fats into tiny droplets. Pancreatic lipase then breaks down triglycerides into di- and monoglycerides and finally into glycerol and fatty acids, which can be absorbed by the intestinal lining.

Discover NCERT Exemplar Class 11th Biology Solution Digestion And Absorption- Long Answer Type Questions

Question:1

A person had roti and dal for his lunch. Trace the changes in those during its passage through the alimentary canal.

Answer:

Let us first determine what nutrients the man is taking. Roti mainly consists of carbohydrates and fibres, whereas dal contains protein. It may also contain fat due to the addition of oil during cooking.
Thus, the trajectory of the diet would be as follows:

a) Oral Cavity: Saliva is mixed with food, making it a semi-solid paste, which is easier to digest. Moreover, the enzyme, salivary amylase, in saliva digests starch. The starch of food is converted into maltose during this process.
b) Oesophagus: No digestion occurs inside the oesophagus.
c) Stomach: Food, once it reaches the stomach, is further churned into an even finer paste. Hydrochloric acid is mixed with the food, which kills germs in the food, if any, as well as provides an acidic pH for optimum activity of pepsin. Partial digestion of protein begins in the stomach. Here, proteins are converted into peptones and proteoses.
d) Small intestine: Pancreatic juices flow till here. They contain pancreatic amylase, which converts polysaccharides into disaccharides. This step further processes the carbohydrates from the roti. Chymotrypsin further breaks peptones and proteoses into dipeptides. Intestinal juice contains various enzymes, which help in the digestion of all the nutrients. The dipeptides are broken down into Amino acids by the enzyme Dipeptidases. Maltose breaks down into glucose with the help of Maltase. Lactose breaks down into glucose and galactose with the help of lactase. Sucrose breaks into glucose and fructose with the help of Sucrase. The di- and monoglycerides are broken down into fatty acids and glycerol with the help of Lipases.

Once all the nutrients are finally converted into their simpler forms, they get absorbed by the walls of the small intestine. After that, the remaining undigested food is sent to the large intestine and is passed on to the rectum.

Question:2

What are the various enzymatic types of glandular secretions in our gut that help with the digestion of food? What is the nature of the end products obtained after the complete digestion of food?

Answer:

a) Secretions from Gastric Glands: These glands secrete gastric juice, which contains hydrochloric acid and the enzyme pepsin. In infants, renin is also secreted by the stomach. Rennin helps in the digestion of milk.

b) Secretions from the Liver: The liver produces the bile juice. Bile does not contain any enzymes but plays an important role in digestion. It facilitates the emulsification of fats so that their digestion can be easier. Bile also provides an alkaline medium so that the enzymes in the small intestine can work.

c) Secretions from Pancreas: The pancreas secretes pancreatic juice, which contains inactive enzymes like amylase, lipase, nuclease, trypsinogen, and chymotrypsinogen. Trypsinogen is activated by the enzyme enterokinase into active trypsin, secreted by the intestinal mucosa. Trypsin, then activate other enzymes in the pancreatic juice. Amylase digests carbohydrates, and trypsin/chymotrypsin digests protein.

d) Secretions from Small Intestine: The small intestine secretes succus entericus, which contains various enzymes, including dipeptidase, lipase, lactase, etc.

e) End Products of Digestion: The final products of digestion are simpler substances like glucose, amino acids, fatty acids, and glycerol. These substances can be easily absorbed by the villi present in the small intestine.

Question:3

Discuss the mechanisms of absorption.

Answer:

The Absorption of digested food happens through three mechanisms, namely: passive, active, or facilitated transport mechanisms.
Simple Diffusion: Small amounts of monosaccharides, amino acids, and some electrolytes are absorbed by diffusion. The passage of the above substances into the blood depends on the concentration gradient.
Facilitated Transport: Fructose, as well as some amino acids, are absorbed with the help of carrier ions like Na+. This method is known as facilitated transport.
Transport of Fatty Acids and Glycerols: These substances are not absorbed into the blood because they are insoluble. They are made into small droplets, called micelles. These move to the intestinal mucosa. In the intestinal mucosa, these micelles get converted into very small protein-coated globules, called chylomicrons. The chylomicrons are then transported into the lymph vessels in the villi. The lymph vessels finally release them into the bloodstream.

Question:4

Discuss the role of the hepatopancreatic complex in the digestion of carbohydrate, protein, and fat components of food.

Answer:

The hepato-pancreatic complex is very crucial for the digestion of carbohydrates, protein, and fat.

Role of Liver: The liver produces the bile juice. Bile does not contain any enzymes but plays an important role in digestion. It facilitates the emulsification of fats so that their digestion can be easier. Bile also provides an alkaline medium so that the enzymes in the small intestine can work.

Role of Pancreas: The Pancreas secretes pancreatic juice, which contains inactive enzymes like amylase, lipase, nuclease, trypsinogen, and chymotrypsinogen. Trypsinogen is activated by the enzyme enterokinase into active trypsin, secreted by the intestinal mucosa. Trypsin, then activate other enzymes in the pancreatic juice. Amylase digests carbohydrates, and trypsin/chymotrypsin digests protein.

Question:5

Explain the process of digestion in the buccal cavity with a note on the arrangement of teeth.

Answer:

Arrangement of Teeth: In human beings, each tooth is embedded in a socket of the jawbone. This type of attachment is known as the diphyodont. Human beings get two sets of teeth in their lifetime, i.e., temporary teeth and permanent teeth. Milk teeth are temporary and are replaced by permanent teeth. This type of arrangement is diphyodont.
There are four types of teeth in human beings, namely incisors, canines, premolars, and molars. Each half of a jaw contains a number of each type of tooth. This can be shown by the following dental formula: 2123/2123. This shows that there are 2 incisors, 1 canine, 2 premolars, and 3 molars in each half of a jaw. Thus, there are a total of 32 teeth in a human adult.

Also, check NCERT Books and NCERT Syllabus here

• NCERT Books Class 11 Biology

• NCERT Syllabus Class 11 Biology

• NCERT Books Class 11

• NCERT Syllabus Class 11

Approach to Solve Questions of Class 11 Biology Chapter 16

Solving the questions is important because having a clear approach helps students break down the chapter into easy-to-understand sections. A step-by-step strategy also helps in answering both direct and tricky application-based questions in exams.

• Read the NCERT and Exemplar to understand the structure and function of the digestive system, including glands and enzymes.

• Practice drawing labeled diagrams of the digestive system and the process of digestion.

• Memorize the sequence of digestion and absorption for carbohydrates, proteins, and fats.

• Solve all questions included in Digestion and Absorption Class 11 NCERT Exemplar, focusing on the role of different enzymes, hormones, and absorption mechanisms.

• Revise key differences, such as between primary and permanent teeth, and the functions of different digestive glands

Also, read the NCERT Solution subject-wise

• NCERT Solutions for Class 11 Maths

• NCERT Solutions for Class 11 Physics

• NCERT Solutions for Class 11 Chemistry

• NCERT Solutions for Class 11 Biology

Main topics of NCERT Exemplar Class 11 Biology Chapter 16

This chapter explains how the human digestive system functions and how nutrients are absorbed in the human body. It covers both anatomical features and the processes involved.

• Human alimentary canal

• Digestive glands and secretions

• Enzymes in digestion

• Absorption in the small intestine

• Digestive system disorders

• Digestive Hormones

• Role of bile

• Mechanical vs chemical digestion

NCERT Exemplar Class 11 Solutions for Other Subjects

• NCERT Exemplar Class 11 Mathematics Solutions
• NCERT Exemplar Class 11 Chemistry Solutions
• NCERT Exemplar Class 11 Physics Solutions

Important Question from NCERT Exemplar Class 11 Biology Chapter 16

This question helps the students to test their understanding of key concepts and is useful for both NEET and school exam preparation.

Question 1: In the process of digestion, what type of digestive activities are primarily associated with the contributions of the liver and pancreas?

Options:

1. Both hepatic secretions involve mechanical breakdown.

2. The liver and pancreas engage in chemical and mechanical digestion, respectively.

3. Both hepatic secretions involve chemical breakdown.

4. The liver and pancreas contribute to mechanical and chemical digestion, respectively.

Answer: The correct answer is option 4)The liver and pancreas contribute to mechanical and chemical digestion, respectively.

Explanation:

The liver primarily helps in mechanical digestion, which involves the physical breakdown of food into smaller pieces. The liver does not directly participate in chemical digestion, which involves the breakdown of food molecules through the action of enzymes. On the other hand, the pancreas plays a crucial role in chemical digestion by secreting digestive enzymes into the small intestine.

Must Read NCERT Notes subject-wise

• NCERT Notes for Class 11 Maths

• NCERT Notes for Class 11 Physics

• NCERT Notes for Class 11 Chemistry

• NCERT Notes for Class 11 Biology

NCERT Exemplar Class 11 Biology Solutions Chapter-Wise

Find below the links to all chapters of Class 11. These answers help in building strong concepts and prepare effectively for exams like NEET and school tests.