Selina Textbook Solutions: Digestive System | Biology Class 6 ICSE PDF Download

 Page 1


Synopsis: 
? The food we consume fall into seven different catagories. 
1. carbohydrates 
2. fats 
3. proteins 
4. minerals 
5. vitamins 
6. water 
7. roughage 
? The process of nutrition is conducted in five steps 
1. ingestion 
2. digestion 
3. absorption 
4. assimilation 
5. egestion 
? When some part of food is chewed, the tongue makes it a spherical mass 
called Bolus. 
? Peristalsis is a wave of constriction in the circular muscles in the wall of the gut to 
push the food further into the food canal. 
? The food canal is also called alimentary canal which starts from the mouth and 
ends at the anus. 
? The digestive glands include 
1. Salivary glands 
2. Liver 
3. Pancreas 
? The teeth which are similar in size and shape are called homodont teeth. 
They are usually found in fishes, frogs, reptiles etc. 
? The last molar on each side in each j aw is called wisdom tooth which appears at 
the age of 17-20 years. 
? The human teeth develop in two sets; the first set is called milk teeth or temporary 
teeth while the second set which replaces the milk teeth are called permament 
teeth. 
? The milk teeth are twenty in number while the permament are thirty two in number. 
? The part of the teeth which can be seen is called crown while the part which is 
fixed in the jaw is called root. 
? The tooth is made up of: 
1. enamel 
2. dentin 
3. pulp 
? The hardest substance of the body is called Enamel. 
? The yellow, stick substance found on the teeth due to poor oral hygeine is 
called plaque. It consists of sugar and bacteria. 
? Mineralised or hard plaque is called tartar. 
? The functions of tongue are: 
1. manipulates food while chewing 
Page 2


Synopsis: 
? The food we consume fall into seven different catagories. 
1. carbohydrates 
2. fats 
3. proteins 
4. minerals 
5. vitamins 
6. water 
7. roughage 
? The process of nutrition is conducted in five steps 
1. ingestion 
2. digestion 
3. absorption 
4. assimilation 
5. egestion 
? When some part of food is chewed, the tongue makes it a spherical mass 
called Bolus. 
? Peristalsis is a wave of constriction in the circular muscles in the wall of the gut to 
push the food further into the food canal. 
? The food canal is also called alimentary canal which starts from the mouth and 
ends at the anus. 
? The digestive glands include 
1. Salivary glands 
2. Liver 
3. Pancreas 
? The teeth which are similar in size and shape are called homodont teeth. 
They are usually found in fishes, frogs, reptiles etc. 
? The last molar on each side in each j aw is called wisdom tooth which appears at 
the age of 17-20 years. 
? The human teeth develop in two sets; the first set is called milk teeth or temporary 
teeth while the second set which replaces the milk teeth are called permament 
teeth. 
? The milk teeth are twenty in number while the permament are thirty two in number. 
? The part of the teeth which can be seen is called crown while the part which is 
fixed in the jaw is called root. 
? The tooth is made up of: 
1. enamel 
2. dentin 
3. pulp 
? The hardest substance of the body is called Enamel. 
? The yellow, stick substance found on the teeth due to poor oral hygeine is 
called plaque. It consists of sugar and bacteria. 
? Mineralised or hard plaque is called tartar. 
? The functions of tongue are: 
1. manipulates food while chewing 
2. helps in tasting the food 
3. mixes food with saliva 
4. cleans the teeth. 
5. helps in speaking. 
? The enzyme contained in saliva is called amylase which digests starch into 
glucose. 
? The food pipe is the oesophagus. No digestion takes here 
 
 
The organ which serves for both digestion and absorption of the food is small 
intestine. 
? The small intestine is 7 metres long while the large intestine is 1.5 metres long. 
? No enzyme is secreted by the large intestine. 
? Glucose, amino acids, vitamins and minerals are transported to the liver. 
? Amino acids are used in the production of proteins for growth and repair of 
tissues. 
Review Questions 
Multiple Choice Questions : 
1. Put a tick ( ?) against the most appropriate alternative in the following 
statements. 
 
(1) The teeth which help in tearing the food are the: 
(a) Incisors 
(b) Canines 
(c) Premolars 
(d) Molars 
(ii) Last molar tooth in human beings is called: 
(a) Adult tooth 
(b) Wisdom tooth 
Page 3


Synopsis: 
? The food we consume fall into seven different catagories. 
1. carbohydrates 
2. fats 
3. proteins 
4. minerals 
5. vitamins 
6. water 
7. roughage 
? The process of nutrition is conducted in five steps 
1. ingestion 
2. digestion 
3. absorption 
4. assimilation 
5. egestion 
? When some part of food is chewed, the tongue makes it a spherical mass 
called Bolus. 
? Peristalsis is a wave of constriction in the circular muscles in the wall of the gut to 
push the food further into the food canal. 
? The food canal is also called alimentary canal which starts from the mouth and 
ends at the anus. 
? The digestive glands include 
1. Salivary glands 
2. Liver 
3. Pancreas 
? The teeth which are similar in size and shape are called homodont teeth. 
They are usually found in fishes, frogs, reptiles etc. 
? The last molar on each side in each j aw is called wisdom tooth which appears at 
the age of 17-20 years. 
? The human teeth develop in two sets; the first set is called milk teeth or temporary 
teeth while the second set which replaces the milk teeth are called permament 
teeth. 
? The milk teeth are twenty in number while the permament are thirty two in number. 
? The part of the teeth which can be seen is called crown while the part which is 
fixed in the jaw is called root. 
? The tooth is made up of: 
1. enamel 
2. dentin 
3. pulp 
? The hardest substance of the body is called Enamel. 
? The yellow, stick substance found on the teeth due to poor oral hygeine is 
called plaque. It consists of sugar and bacteria. 
? Mineralised or hard plaque is called tartar. 
? The functions of tongue are: 
1. manipulates food while chewing 
2. helps in tasting the food 
3. mixes food with saliva 
4. cleans the teeth. 
5. helps in speaking. 
? The enzyme contained in saliva is called amylase which digests starch into 
glucose. 
? The food pipe is the oesophagus. No digestion takes here 
 
 
The organ which serves for both digestion and absorption of the food is small 
intestine. 
? The small intestine is 7 metres long while the large intestine is 1.5 metres long. 
? No enzyme is secreted by the large intestine. 
? Glucose, amino acids, vitamins and minerals are transported to the liver. 
? Amino acids are used in the production of proteins for growth and repair of 
tissues. 
Review Questions 
Multiple Choice Questions : 
1. Put a tick ( ?) against the most appropriate alternative in the following 
statements. 
 
(1) The teeth which help in tearing the food are the: 
(a) Incisors 
(b) Canines 
(c) Premolars 
(d) Molars 
(ii) Last molar tooth in human beings is called: 
(a) Adult tooth 
(b) Wisdom tooth 
(c) Child tooth 
(d) Elders tooth 
(iii) The hardest substance in your body? 
(a) Dentine 
(b) Bone 
(c) Cement 
(d) Enamel 
(iv) Saliva converts starch into: 
(a) Glucose 
(b) Sucrose 
(c) Maltose 
(d) Lactose 
(v) Proteins of the milk are converted into curd by the enzyme: 
(a) Trypsin 
(b) Rennin 
(c) Pepsin 
(d) Steapsin 
(vi) Bile juice ¡s produced by : 
(a) Stomach 
(b) Liver 
(e) Pancreas 
(d) Gall bladder 
1. Write True or False in the following statements. 
1. Molars help in cutting and tearing food. 
False 
Correct — Molars help in finer crushing and grinding. 
2. Carbohydrates are digested into glucose. 
True 
3. Proteins are digested into fatty acids. 
False  
Correct — Proteins is digested into amino acids. 
2. Fill in the blanks. 
1. The teeth called are a total of four in number on the sides of incisors. 
2. The teeth called canines are a total of four in number on the sides of incisors. 
3. Pharynx is a common opening of food pipe and wind pipe. 
4. Molars are meant for crushing the food. 
Page 4


Synopsis: 
? The food we consume fall into seven different catagories. 
1. carbohydrates 
2. fats 
3. proteins 
4. minerals 
5. vitamins 
6. water 
7. roughage 
? The process of nutrition is conducted in five steps 
1. ingestion 
2. digestion 
3. absorption 
4. assimilation 
5. egestion 
? When some part of food is chewed, the tongue makes it a spherical mass 
called Bolus. 
? Peristalsis is a wave of constriction in the circular muscles in the wall of the gut to 
push the food further into the food canal. 
? The food canal is also called alimentary canal which starts from the mouth and 
ends at the anus. 
? The digestive glands include 
1. Salivary glands 
2. Liver 
3. Pancreas 
? The teeth which are similar in size and shape are called homodont teeth. 
They are usually found in fishes, frogs, reptiles etc. 
? The last molar on each side in each j aw is called wisdom tooth which appears at 
the age of 17-20 years. 
? The human teeth develop in two sets; the first set is called milk teeth or temporary 
teeth while the second set which replaces the milk teeth are called permament 
teeth. 
? The milk teeth are twenty in number while the permament are thirty two in number. 
? The part of the teeth which can be seen is called crown while the part which is 
fixed in the jaw is called root. 
? The tooth is made up of: 
1. enamel 
2. dentin 
3. pulp 
? The hardest substance of the body is called Enamel. 
? The yellow, stick substance found on the teeth due to poor oral hygeine is 
called plaque. It consists of sugar and bacteria. 
? Mineralised or hard plaque is called tartar. 
? The functions of tongue are: 
1. manipulates food while chewing 
2. helps in tasting the food 
3. mixes food with saliva 
4. cleans the teeth. 
5. helps in speaking. 
? The enzyme contained in saliva is called amylase which digests starch into 
glucose. 
? The food pipe is the oesophagus. No digestion takes here 
 
 
The organ which serves for both digestion and absorption of the food is small 
intestine. 
? The small intestine is 7 metres long while the large intestine is 1.5 metres long. 
? No enzyme is secreted by the large intestine. 
? Glucose, amino acids, vitamins and minerals are transported to the liver. 
? Amino acids are used in the production of proteins for growth and repair of 
tissues. 
Review Questions 
Multiple Choice Questions : 
1. Put a tick ( ?) against the most appropriate alternative in the following 
statements. 
 
(1) The teeth which help in tearing the food are the: 
(a) Incisors 
(b) Canines 
(c) Premolars 
(d) Molars 
(ii) Last molar tooth in human beings is called: 
(a) Adult tooth 
(b) Wisdom tooth 
(c) Child tooth 
(d) Elders tooth 
(iii) The hardest substance in your body? 
(a) Dentine 
(b) Bone 
(c) Cement 
(d) Enamel 
(iv) Saliva converts starch into: 
(a) Glucose 
(b) Sucrose 
(c) Maltose 
(d) Lactose 
(v) Proteins of the milk are converted into curd by the enzyme: 
(a) Trypsin 
(b) Rennin 
(c) Pepsin 
(d) Steapsin 
(vi) Bile juice ¡s produced by : 
(a) Stomach 
(b) Liver 
(e) Pancreas 
(d) Gall bladder 
1. Write True or False in the following statements. 
1. Molars help in cutting and tearing food. 
False 
Correct — Molars help in finer crushing and grinding. 
2. Carbohydrates are digested into glucose. 
True 
3. Proteins are digested into fatty acids. 
False  
Correct — Proteins is digested into amino acids. 
2. Fill in the blanks. 
1. The teeth called are a total of four in number on the sides of incisors. 
2. The teeth called canines are a total of four in number on the sides of incisors. 
3. Pharynx is a common opening of food pipe and wind pipe. 
4. Molars are meant for crushing the food. 
5. Incisors are used for biting and cutting the food. 
6. The canines are used for tearing the food. 
7.  The premolars and molars are used for crushing and grinding the food. 
8.  In an adult human, there are a total of 32 teeth. 
9. The human teeth appear in two sets, the first set is called primary which consists 
of only twenty teeth. 
3. Name the following : 
1. End product of starch after digestion — glucose. 
2. The organ where protein digestion-begins — stomach. 
3. The organ into which the pancreatic juice and the bile juice are poured — small 
intestine. 
4. The enzyme which digests fat — lipases. 
5. The simplest form of carbohydrates — glucose. ‘ 
6. The part of alimentary canal where water from undigested food is absorbed 
— large intestine. 
7. The end-product of proteins after digestion — amino acids. 
4. Identify and name the four type of teeth shown below and give their functions. 
Answer : 
 
A — incisor 
Function -Its major function is biting and cutting of food. 
B — canine 
Function — Its major function is tearing of the food. 
C — pre-molar 
Function — Used for crushing and grinding of food. 
D — molar 
Function — Used for crushing and grinding of food. 
5. State whether the following statements are True or False. 
 
(i) Wisdom tooth appears at the age of 5-6 years when the child starts going to school. 
(ii) The temporary set of teeth includes incisors, canines and premolars only. 
(iii) The ducts from the salivary glands open into the duodenum. 
(iv) Saliva changes starch into maltose. 
Page 5


Synopsis: 
? The food we consume fall into seven different catagories. 
1. carbohydrates 
2. fats 
3. proteins 
4. minerals 
5. vitamins 
6. water 
7. roughage 
? The process of nutrition is conducted in five steps 
1. ingestion 
2. digestion 
3. absorption 
4. assimilation 
5. egestion 
? When some part of food is chewed, the tongue makes it a spherical mass 
called Bolus. 
? Peristalsis is a wave of constriction in the circular muscles in the wall of the gut to 
push the food further into the food canal. 
? The food canal is also called alimentary canal which starts from the mouth and 
ends at the anus. 
? The digestive glands include 
1. Salivary glands 
2. Liver 
3. Pancreas 
? The teeth which are similar in size and shape are called homodont teeth. 
They are usually found in fishes, frogs, reptiles etc. 
? The last molar on each side in each j aw is called wisdom tooth which appears at 
the age of 17-20 years. 
? The human teeth develop in two sets; the first set is called milk teeth or temporary 
teeth while the second set which replaces the milk teeth are called permament 
teeth. 
? The milk teeth are twenty in number while the permament are thirty two in number. 
? The part of the teeth which can be seen is called crown while the part which is 
fixed in the jaw is called root. 
? The tooth is made up of: 
1. enamel 
2. dentin 
3. pulp 
? The hardest substance of the body is called Enamel. 
? The yellow, stick substance found on the teeth due to poor oral hygeine is 
called plaque. It consists of sugar and bacteria. 
? Mineralised or hard plaque is called tartar. 
? The functions of tongue are: 
1. manipulates food while chewing 
2. helps in tasting the food 
3. mixes food with saliva 
4. cleans the teeth. 
5. helps in speaking. 
? The enzyme contained in saliva is called amylase which digests starch into 
glucose. 
? The food pipe is the oesophagus. No digestion takes here 
 
 
The organ which serves for both digestion and absorption of the food is small 
intestine. 
? The small intestine is 7 metres long while the large intestine is 1.5 metres long. 
? No enzyme is secreted by the large intestine. 
? Glucose, amino acids, vitamins and minerals are transported to the liver. 
? Amino acids are used in the production of proteins for growth and repair of 
tissues. 
Review Questions 
Multiple Choice Questions : 
1. Put a tick ( ?) against the most appropriate alternative in the following 
statements. 
 
(1) The teeth which help in tearing the food are the: 
(a) Incisors 
(b) Canines 
(c) Premolars 
(d) Molars 
(ii) Last molar tooth in human beings is called: 
(a) Adult tooth 
(b) Wisdom tooth 
(c) Child tooth 
(d) Elders tooth 
(iii) The hardest substance in your body? 
(a) Dentine 
(b) Bone 
(c) Cement 
(d) Enamel 
(iv) Saliva converts starch into: 
(a) Glucose 
(b) Sucrose 
(c) Maltose 
(d) Lactose 
(v) Proteins of the milk are converted into curd by the enzyme: 
(a) Trypsin 
(b) Rennin 
(c) Pepsin 
(d) Steapsin 
(vi) Bile juice ¡s produced by : 
(a) Stomach 
(b) Liver 
(e) Pancreas 
(d) Gall bladder 
1. Write True or False in the following statements. 
1. Molars help in cutting and tearing food. 
False 
Correct — Molars help in finer crushing and grinding. 
2. Carbohydrates are digested into glucose. 
True 
3. Proteins are digested into fatty acids. 
False  
Correct — Proteins is digested into amino acids. 
2. Fill in the blanks. 
1. The teeth called are a total of four in number on the sides of incisors. 
2. The teeth called canines are a total of four in number on the sides of incisors. 
3. Pharynx is a common opening of food pipe and wind pipe. 
4. Molars are meant for crushing the food. 
5. Incisors are used for biting and cutting the food. 
6. The canines are used for tearing the food. 
7.  The premolars and molars are used for crushing and grinding the food. 
8.  In an adult human, there are a total of 32 teeth. 
9. The human teeth appear in two sets, the first set is called primary which consists 
of only twenty teeth. 
3. Name the following : 
1. End product of starch after digestion — glucose. 
2. The organ where protein digestion-begins — stomach. 
3. The organ into which the pancreatic juice and the bile juice are poured — small 
intestine. 
4. The enzyme which digests fat — lipases. 
5. The simplest form of carbohydrates — glucose. ‘ 
6. The part of alimentary canal where water from undigested food is absorbed 
— large intestine. 
7. The end-product of proteins after digestion — amino acids. 
4. Identify and name the four type of teeth shown below and give their functions. 
Answer : 
 
A — incisor 
Function -Its major function is biting and cutting of food. 
B — canine 
Function — Its major function is tearing of the food. 
C — pre-molar 
Function — Used for crushing and grinding of food. 
D — molar 
Function — Used for crushing and grinding of food. 
5. State whether the following statements are True or False. 
 
(i) Wisdom tooth appears at the age of 5-6 years when the child starts going to school. 
(ii) The temporary set of teeth includes incisors, canines and premolars only. 
(iii) The ducts from the salivary glands open into the duodenum. 
(iv) Saliva changes starch into maltose. 
Answer : 
(iv) True (V) Saliva changes starch into maltose. 
6.Fill in the blanks in the table (1-5) by selecting the suitable names of substances 
from the list given below: 
(steapsin, peptones, fatty acids, proteoses, protein). 
 
Answer : 
 
Question 7. 
(i) Name the juice secreted by the liver. 
Ans. Bile 
(ii) Name the organ where this juice is temporarily stored. 
Ans. Gallbladder 
(iii) What is the main function of this juice ? 
Ans. The main function of bile is digestion of fats. 
Question 8. 
Name the three enzymes found in pancreatic juice. 
(i)….. (ii)….. (iii) …… 
Answer : 
(i) Starch digesting — amylase 
(ii) Protein digesting — trypsin 
(iii) Fat – digesting — lipases 
Question 9. 
Name the three regions of the large intestine. 
Answer : 
1. Caecum 
2. Colon 
3. Rectum