Human Digestive System Class-6 Srijan ICSE Biology Solutions Chapter-4

Human Digestive System Class-6 Srijan ICSE Biology Solutions Chapter-4 Veer Bala Rastogi Srijan Publishers Solutions. We Provide Step by Step Solutions of  Fill in the blanks, Give functions, Define the following, Differentiate between the following, Match the following, True and False, MCQs and Answer these Questions of Veer Bala Rastogi Srijan Biology Publishers. Visit official Website CISCE for detail information about ICSE Board Class-6.

Human Digestive System Class-6 Srijan ICSE Biology Solutions Chapter-4

Board ICSE
Class 6th
Subject Biology
Book Name Srijan
Chapter-4 Human Digestive System
Unit-1 Human Digestive System
Topic Solution of exercise questions
Session 2023-24

Human Digestive System ICSE Class-6th Srijan

Biology Solutions Chapter-4

A. Fill in the blanks with suitable words:

1. Starch is digested into maltose.

2. The opening of oesophagus into stomach is called gullet.

3. Tongue helps in swallowing the food.

4. Bile is stored in gall blander.

5. Wisdom teeth are the four molars added in permanent teeth.

6. The finger-like outgrowths in small intestine are called villi.

7. Carbohydrates and fats are energy rich foods.

B. Give one word for the following:

Question: 1. Arrangement of different types of teeth in buccal cavity.

Answer: 2 central incisor, 2 lateral incisor, 2 canine, 4 premolar and 6 molar in upper and lower jaw

Question: 2. Enzyme present in the saliva for starch digestion.

Answer: Salivary Amylase

Question: 3. Teeth for tearing food.

Answer: Canines (fangs)

Question: 4. The progressive wave of contraction that proceeds along the wall of oesophagus.

Answer: Peristalsis

Question: 5. The semi digested food that passes from stomach into intestine.

Answer: Chyme

C. Define these terms:

Question: 1. Chewing

Answer: Biting and grinding food in your mouth so it becomes soft enough to swallow.

Question: 2. Assimilation

Answer: The process whereby individuals or groups of differing ethnic heritage are absorbed into the dominant culture of a society.

Question: 3. Ingestion

Answer: Ingestion is the consumption of a substance by an organism.

Question: 4. Faces

Answer: The front part of the head that in humans extends from the forehead to the chin and includes the mouth, nose, cheeks, and eyes.

Question: 5. Kwashiorkor

Answer: Kwashiorkor is a type of malnutrition characterized by severe protein deficiency.

Question: 6. Emulsification

Answer: Emulsification is the process by which the dispersed phase is broken up into small droplets.

D. Differentiate between the following:

Question: 1. Ingestion and egestion


Ingestion Egestion
1. It is the first step of the digestive process. 1. It is the last step of the digestive process.
2. It is an intake of food into the mouth. 2. It is the removal or elimination of waste or feces of the body.
3. This process uses the mouth part for ingestion. 3. This process uses the anus part for egestion.
Question: 2. Healthy food and junk food


Healthy Food Junk Food
1. Rich in nutrients viz. protein, carbohydrate, dietary fibers, fats, vitamins, minerals… etc. Low or no nutrients, but rich in saturated fats, salt, sugars, artificial flavors… etc.
2. Prevents consumers from cancer, diabetes, heart diseases, and obesity Causes the consumers to have cancer, diabetes, heart diseases, and obesity
3. Not convenient to access and prepare Very convenient to access and mostly prepared and ready to eat
4. Mostly natural Mostly artificial
Question: 3. Pepsin and trypsin


Pepsin Trypsin
1. It is an enzyme which is secreted by the stomach. It is an enzyme secreted by pancreas.
2. It is involved in digestion of proteins which are found in ingested food. It also helps in digestion of partially digested proteins in the stomach and then converts them into dipeptides.
3. It is secreted as an inactive zymogen known as pepsinogen. It is secreted as an inactive form known as trypsinogen.
Question: 4. Bile and pancreatic juice.


Bile Juice Pancreatic Juice
1. Bile juice is secreted by liver Pancreatic juice is secreted by pancreas.
2. Bile juice does not contains any types of enzymes. Pancreatic juice contains enzymes like amylase, trypsin and lipase
3. Bile juice acts only on fats. Pancreatic juice acts on carbohydrates, proteins and fats

E. Answer these questions:

Question: 1. Define nutrition. Summaries the steps involved in the process of nutrition.

Answer: Nutrition is a method in which the food is consumed by the organisms and utilizing the nutrients from the food. Nutrition is the process of taking in food and converting it into energy and other vital nutrients required for life. In the process of nutrition, organisms utilize nutrients. The main nutrients are carbohydrates, fat, protein, vitamins, minerals, and roughage.

The five steps of nutrition are ingestion, digestion, absorption, assimilation, and egestion. Ingestion is the process by which food particles are consumed via the mouth. In digestion, the food particles are digested by enzymes that break down the food particles into smaller molecules.

Question: 2. What is alimentary canal? Name its different parts.

Answer: The alimentary tract of the digestive system is composed of the mouth, pharynx, esophagus, stomach, small and large intestines, rectum and anus. Associated with the alimentary tract are the following accessory organs: salivary glands, liver, gallbladder, and pancreas.

Question: 3. How many types of teeth are there in the permanent set of teeth in man? Name different types and their functions.

Answer: Most adults have 32 permanent teeth, including eight incisors, four canines, eight premolars and 12 molars. There are four major types of teeth: incisor, canines, premolars and molars:

  • Incisors: They are needed for biting and cutting food.
  • Canines: They are needed for tearing food.
  • Premolars: They are needed to tear and crush food.
  • Molars: They are needed to chew, crush and grind food.
Question: 4. What are enzymes? Name the digestive enzymes present in pancreatic juice. Give their role in digestion.

Answer: Enzymes are proteins that help speed up metabolism, or the chemical reactions in our bodies. The enzymes that are present in pancreatic juice are Trypsin, amylase, and lipase.

Question: 5. What is a lacteal? What is its functions?

Answer: lacteal is a lymphatic capillary that is located in the villi of the small intestine. The function of the lacteal in the small intestine: During the process of digestion, the lacteals absorb large molecules of fats and lipids from the small intestine which gives them a milky-white appearance.

Question: 6. What are villi? Give their functions.

Answer: Villi are finger-like projections which are richly supplied with blood vessels. They are present in the inner lining of the small intestine and help in the absorption of nutrients by increasing the surface area for absorption.

Question: 7. Write the functions of tongue. Draw the structure of tongue and show the location of different taste buds on it.

Answer: The tongue functions as a digestive organ by facilitating the movement of food during mastication and assisting swallowing. Other important functions include speech and taste.

Draw the structure of tongue

F. Match the columns:

Column A Column B
1. Proteins (a) Fatty acids and glycerol
2. Lipids (b) Simple sugar
3. Carbohydrates (c) Amino acids
4. Salivary juice (d) Liver
5. Bile juice (e) Buccal cavity


Column A Column B
1. Proteins (a) Amino acids
2. Lipids (b) Fatty acids and glycerol
3. Carbohydrates (c) Simple sugar
4. Salivary juice (d) Buccal cavity
5. Bile juice (e) Liver

G. State whether the following statements are true or false. If false, rewrite the correct form of statements:

Statements True/False
1. Saliva changes starch into sugar. T
2. Tongue helps in mixing of saliva with food. T
3. Bile is produced by gall blander. F
4. Digestion is completed in large intestine. F
5. The permanent teeth are without molars. F

H. Give reasons for the following:

Question: 1. Digestion is essential.

Answer: Digestion is important for breaking down food into nutrients, which the body uses for energy, growth, and cell repair.

Question: 2. No digestion occurs in oesophagus.

Answer: There is no digestion in oesophagus because it does not contains any digestive glands that release enzymes necessary for digestion of food.

Question: 3. Stomach wall is thick and muscular.

Answer: The wall of stomach is thick and muscular as it has many digestive glands which secrete digestive juices, mucus and hydrochloric acid.

Question: 4. We cannot digest cellulose.

Answer: Humans are unable to digest cellulose because we lack appropriate enzymes (cellulase) to break down this complex substance, cellulose.

Question: 5. Hydrochloric acid secreted by gastric glands does not damage the stomach wall.

Answer: Gastric glands in the stomach release hydrochloric acid, enzyme pepsin and mucus. Mucus protects the inner lining of the stomach from the action of hydrochloric acid and enzyme pepsin. If mucus is not released, it will lead to erosion of the inner lining of the stomach leading to acidity and ulcers.

I. Give functions of the following:

Question: 1. Salivary glands

Answer: Human salivary glands produce between 0.5 to 1.5 L of saliva daily, facilitating mastication, swallowing, and speech, lubricating the oral mucosa, and providing an aqueous medium for taste perception.

Question: 2. Teeth

Answer: Teeth break down the larger food particles into smaller particles while chewing and grinding the food: Incisors and canine cut the food or flesh, while the premolars and molars help with grinding and chewing for physical breakdown of food after ingestion.

Question: 3. Oesophagus

Answer: The primary function of the esophagus is to transport food entering the mouth through the throat and into the stomach. This function begins at the very beginning of the esophagus, following some taste buds located on the organ, at the upper esophageal sphincter (UES).

Question: 4. Lacteal

Answer: The lacteals absorb large molecules of fats and lipids from the small intestine which gives them a milky-white appearance.

Question: 5. Gall bladder

Answer: Gallbladder is part of your digestive system. Its main function is to store bile. Bile helps your digestive system break down fats.

Question: 6. Rectum

Answer: The primary function of the rectum is to collect and hold your poop until it’s time to release it.

J. Multiple Choice Questions:

1. This is a digestive gland

(a) Tongue

(b) Tooth

(c) Stomach

(d) Liver

Answer: option (d) Liver is correct.

2. Breakdown of complex insoluble organic compounds into simple soluble molecules is

(a) Digestion

(b) Absorption

(c) Assimilation

(d) Egestion

Answer: option (a) Digestion is correct.

3. This organ begins with mouth and ends with anus

(a) Stomach

(b) Alimentary canal

(c) Foodpipe

(d) Oesophagus

Answer: option (b) Alimentary canal is correct.

4. Hydrochloric acid in stomach

(a) Helps in the digestion of fats

(b) Kills bacteria ingested along with food

(c) Converts starch into sugars

(d) Helps in the digestion of protein

Answer: option (b) Kills bacteria ingested along with food is correct.

5. Gastric glands are found in

(a) Stomach

(b) Buccal cavity

(c) Liver

(d) Large intestine

Answer: option (a) Stomach is correct.

6. The leaf-like pink gland in human body is

(a) Liver

(b) Villi

(c) Lacteal

(d) Pancreas

Answer: option (d) Pancreas is correct.

7. Fat is broken down to fatty acids and glycerol by

(a) Lipase

(b) Amylase

(c) Trypsin

(d) Bile salts

Answer: option (a) Lipase is correct.

8. In man, digestion of starch starts in

(a) Buccal cavity

(b) Stomach

(c) Oesophagus

(d) Duodenum

Answer: option (a) Buccal cavity is correct.

— : End of  Human Digestive System Class-6 Srijan ICSE Biology Solutions Chapter-4:–

Return to- ICSE Class -6 Srijan Biology Solutions


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