RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Rajasthan Board RBSE Class 7 Science Chapter 2 Nutrition in Animals

RBSE Solutions for Class 7 Science

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

RBSE Class 7 Science Nutrition in Animals Intext Questions and Answers

Page No 15.

Question 1.
How does digestion of food occur in a human body?
Answer:
All parts of alimentary canal in human beings collectively digest food The inner wall of stomach. small intestine and all glands associated with alimentary canal for

example –
Salivary gland. liver, pancreas etc. secrete digestive juices. Digestive juices convert complex components of food into simpler substances. Thus digestion begins

page No 16.

Question 2.
Are all teeth alike in appearance ?
Answer:
No. All teeth are not alike in appearance. Based on texture. size and functions of teeth. some are sharp. some are pointed and some arc rough. These are not alike.

Question 3.
What is the difference in the texture of the teeth ?
Answer:
Based on texture. some teeth are sharp. some are pointed and some are rough.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 4.
What is the difference in functions of various teeth ?
Answer:
Teeth can be classified based on their functions like as –

  1. Some teeth are used in cutting food.
    Example – Incisor teeth
  2. Sonic teeth are used in piercing & tearing food.
    For example – Canine teeth,
  3. Sonic teeth are used in chewing food. For
    example – Molar & Premolar teeth.

Page No 18.

Question 5.
Do you know the functions of the tongue ?
Answer:
Tongue has taste buds that detect different tastes of food. It mixes Saliva with the food during chewing. It also helps in swallowing food. for talking and cleaning our teeth.

Page No 19.

Question 6.
What is the role of Villi in the intestine?
Answer:
The Villi increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorb he digested food materials. The absorbed substances are transported a the blood vessels to different organs of the body.

RBSE Class 7 Science Nutrition in Animals Text Book Questions and Answers

Choose the most appropriate option:

Question 1.
Number of incisors in buccal cavity of human being –
(a) 2
(b) 4
(c) 6
(d) 8
Answer:
(d) 8

Question 2.
Organ in which absorption of digested food takes place.
(a) Stomach
(b) Small intestine
(c) Large intestine
(d) Mouth
Answer:
(b) Small intestine

Question 3.
A part of our body which has digestive juice.
(a) Large intestine
(b) Small intestine
(c) Stomach
(d) Oesophagus
Answer:
(c) Stomach

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Fill in the blanks with appropriate words:

  1. Amoeba captures food with the help of ……………………..
  2. In ruminants …………………….. is located between the small intestine and large intestine.
  3. By …………………….. On the tongue reveals taste.

Answer:

  1. Pseudopodia
  2. Calcum.
  3. Tastebuds.

Short Answer Questions:

Question 1.
What is a process of Ingestion ?
Answer:
Food is taken into the body through the mouth, The process of taking food into the bod is called ingestion.

Question 2.
If tongue does not have taste buds, which process is affected ?
Answer:
Tongue has taste buds to detect different tastes of food which are found at various sites on tongue. We detect various tasks like sweet. sour. salt, bitter etc. with the help of these taste buds. If tongue doesn’t have taste buds. we cannot detect about various tastes of food materials. We ill feel all foods tasteless in absence of these taste buds.

Question 3.
If ruminants doesn’t have calcium, what happened ?
Answer:
Grass eating animals are called ruminants. These have a large sac like structure between the small intestine and large intestine, called calcium. The cellulose of the food is digested here b the action of certain bacteria which are not present in humans. Hence if ruminants do not have calcium. cellulose present in food materials cannot be digested.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 4.
Write name and functions of different types of teeth of human.
Answer:
There arc total 32 teeth found in human beings which are categorized in four classes based on their functions and other specifications. Their types and functions are as follows –

  1. Incisor – These type of teeth cut food. These are total four in no. in lore Jaw as well as in upper jaw.
  2. Canine – These pierce and tear food. These arc total two in number in lower Jaw as well as in upper
  3. Premolar – These teeth arc used in chewing food. These are four in number in each Jaw.
  4. Molar – These teeth help in chewing food more fine. These arc total six in number in each Jaw.

Large Answer Questions:

Question 1.
How does digestion of food take place in stomach ?
Answer:
The stomach is a thick called bag. Its shape is like a flattened U and it is the widest part of the alimentary canal. It receives food from the food pipe a one end and opens into the small intestine at the other. Digestion of food in Stomach – As food reaches in stomach. peristaltic motion get started in muscles of thick-walled stomach so that food can be mixed well.

The peptic glands of stomach secrete mucous. hydrochloric acid and digestive juices. Hydrochloric acid makes the medium in the stomach acidic and kills man bacteria that enter along with the food. The digestive juices break don the proteins into simpler substance. Food becomes paste like in stomach which is pushed further in small intestine.

Question 2.
Describe a method of feeding and digestion in Amoeba by a labeled diagram.
Answer:
Amoeba is a single-celled organism found in water bodies. Amoeba constantly changes its shape and position. Amoeba has a cell membrane. a rounded dense nucleus and many small bubble-like vacuoles in its cytoplasm. It pushes out one or more finger-like projections called pseudopodia. for movement and capture of food. Amoeba feeds on some microscopic organisms. When it senses food, it pushes out pseudopodia around the food particle and engulfs it. The food becomes trapped in a food vacuole. This method of nutrition found in amoeba is called Endocytosis.
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-1
Digestive Juices arc secreted into the food vacuole. They act on the food and break it down into simpler substances. Gradually the digested food is absorbed. The absorbed substances arc used for growth. maintenance and multiplication. The undigested residue of the food is expelled outside by the vacuoles.

Question 3.
Draw a labeled diagram of digestive system of humans ?
Answer:
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-2

RBSE Class 7 Science Nutrition in Animals Important Question and Answers

Objective Type Questions:

Question 1.
Trapping of food materials in food vacuole of Amoeba is called –
(a) Endocyclotis
(b) Endocytosis
(c) Extrocytosis
(d) Extrocycloris
Answer:
(b) Endocytosis

Question 2.
How many teeth are found in human beings –
(a) 31
(b) 33
(c) 32
(d) 34
Answer:
(c) 32

Question 3.
Amoeba pushes out finger like projections. What are these known as?
(a) Endocytosis
(b) Pseudopodia
(c) Buds
(d) None of these
Answer:
(b) Pseudopodia

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 4.
Grass- eating animals are called as –
(a) Ruminants
(b) Endocytosis
(c) Rumen
(d) Rumination
Answer:
(a) Ruminants

Question 5.
Molar teeth look in appearance as –
(a) Sharp
(b) Pointed
(c) Rough
(d) None of these
Answer:
(c) Rough

Fill in the blanks:

  1. Amoeba is a …………………………. organism found iii water bodies. (Unicellular / Multicellular)
  2. The grass is rich in …………………………. (Protein / Cellulose)
  3. Mainly undigested food material of food is expelled as …………………………. (Faeces / omit)
  4. Alimentary canal and associated glands together constitute …………………………. (Alimentary canal / digestive System)
  5. The bile juice plays an important role in the digestion of …………………………. (Fats / carbohydrates)

Answer:

  1. Unicellular
  2. Cellulose
  3. Faeces
  4. Digestive system
  5. Fat

Match the column I with column II –
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-3
Answer:

  1. (b)
  2. (d)
  3. (a)
  4. (c)
  5. (c)

Very Short Answer Questions:

Question 1.
What is Rumen ?
Answer:
Crass – eating animals quickly swallow the grass and store it in a separate part of the stomach. called rumen.

Question 2.
Which carbohydrate is found in grass?
Answer:
Cellulose is the carbohydrate which is found in grass.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 3.
What are ruminant animals ?
Answer:
Grass – eating animals which do rumination process are known as ruminants.
Example – Buffalo. Cow. etc.

Question 4.
What is calcium ?
Answer:
It is a large sac-like structure between the small intestine and large intestine, found in ruminants

Question 5.
What is the function of calcium ?
Answer:
The cellulose of the food is digested n calcium b the action of certain bacteria which are not present in humans.

Question 6.
What do you mean by ingestion of food?
Answer:
The process of taking food into the body is called ingestion.

Question 7.
Where salivary glands situated? Which juice is secreted by these glands?
Answer:
Salivary glands are situated in our mouth and these secretes saliva.

Question 8.
Where are taste buds found ?
Answer:
Taste buds are found on tongue.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 9.
what is the function of taste buds ?
Answer:
With the help of taste buds. We can taste various type of tastes. Such as bitter, sweet, salty, sour, etc.

Question 10.
What is the function of peptic juice ?
Answer:
The digestive juices in stomach (peptic juice) break down the proteins into simpler substances.

Question 11.
Which gland is the largest in human beings ?
Answer:
Liver is the largest gland in human body.

Question 12.
Where is bile juice synthesized? and where it is stored ?
Answer:
Bile juice is synthesized in liver and it is stored in a sac called the gall bladder

Question 13.
What is function of bile juice ?
Answer:
The bile plays an important role in the digestion of fats.

Question 14.
Where pancreatic juice is synthesized?
Answer:
Pancreatic juice is synthesized in pancreas.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 15.
What is function of pancreatic juice?
Answer:
The pancreatic juice acts on carbohydrates and proteins and changes them into simpler form

Question 16.
Where digested food is absorbed?
Answer:
Digested food is absorbed in small intestine.

Question 17.
What is nutrition ?
Answer:
The mode of intake of needed food for growth. development and good health of the body is called nutrition.

Question 18.
At times the food is vomited out. What is cause of it ?
Answer:
When the food is not accepted b our stomach. then it is vomited out.

Short Answer Questions:

Question 1.
What is digestion ?
Answer:
Our ingested food contains complex substances like carbohydrates. fats, proteins. vitamins and minerals. These complex substances cannot be utilized as such. So they are broken don into simplex substances. The conversion or breakdown of complex components of food into simpler substances is called digestion.

Question 2.
Describe Amoeba in short.
Answer:
Amoeba is a single celled organism found in water bodies. Amoeba has a cell membrane. a rounded dense nucleus and mans’ small bubble like vacuoles in its cytoplasm. Amoeba constantly changes its shape and position. It pushes out one or more finger like projections. called pseudopodia. These help it in movement and capturing food. Amoeba feeds on some microscopic organisms.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 3.
What is endocytosis ?
Answer:
Amoeba feeds on some microscopic organisms. When it senses food, it pushes out pseudopodia around the food particle and engulfs it. The food becomes trapped in a food vacuole. Digestive juices are secreted into the food vacuole. This method of nutrition is know as Endocytosis.

Question 4.
What is rumination ?
Answer:
Animals such as buffaloes. etc. quickly swallow the grass and store it in a separate part of the stomach called rumen (first stomach). Here the food gets partially digested and now it is called cud. But later the cud returns to the mouth in small lumps and the animal chews it. This process is called rumination and these animals are called ruminants.

Question 5.
What is cud?
Answer:
Grass – eating animals quickly swallow the grass and store it in a separate part of the stomach This part of stomach is known as rumen. Here the food gets partially digested and is called cud.

Question 6.
What are the functions of salivary juice ?
Answer:
When we chew the food. Saliva secreted from salivary glands and mixes with food. Food becomes moisten and bolus by mixing saliva. The partial digestion of food starts here. Moisten and bolus food is easy to swallow.

Question 7.
What is liver ?
Answer:
The liver is a reddish brown gland situated in the upper part of the abdomen on the right side. It is the largest gland of the body. It secretes bile juice that is stored in a sac called the gall bladder. The bile plays an important role in the digestion of fats.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 8.
What is pancreas gland
Answer:
The pancreas is a large cream coloured gland located just below the stomach. The pancreatic juice acts on carbohydrates and proteins and changes them into simpler forms.

Question 9.
Describe the large intestine with labeled diagram.
Answer:
Large intestine is an important part of alimentary canal. The large intestine is wider and shorter than small intestine. It is about 1.5 meters in length. Its function is to absorb water and some salts from the undigested food material. The remaining waste passes into the rectum.
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-4

Question 10.
What is egestion ?
Answer:
The remaining waste passes into the rectum and remains there a semi-solid faeces. The faecal matter is removed through the anus from time to time. This is called egestion.

Question 11.
Represent the type of human teeth and their number in a tabular form.
Answer:
Type of teeth and their number in human beings –
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-5

Question 12.
What is alimentary canal in human beings ? How many parts it contains ?
Answer:
The food passes through a continuous canal which begins at the buccal cavity and ends at the anus. This canal is called as alimentary canal. The alimentary canal of human can be divided into various components –

  1. the buccal cavity
  2. food pipe or oesophagus
  3. stomach
  4. small intestine
  5. large intestine
  6. anus.

Question 13.
How food moves in oesophagus?
Answer:
The swallowed food by mouth passes into the food pipe. The food pipe runs along the neck and the chest. Food is pushed don by movement of the wall of the food pipe, Actually this movement takes place throughout the alimentary canal and pushes the food down wards.

Question 14.
What is digestive system ? Explain.
Answer:
The various parts of human alimentary canal, from buccal cavity to anus, together form digestive system. The food components gradually get digested as food travels through the various compartments. The inner walls of the stomach and the small intestine, and the various glands such as salivary glands, the liver and the pancreas secrete digestive jucies. The digestive juices convert complex substances of food into simpler ones. The digestive tract and the associated glands together constitute the digestive system.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 15.
What is tongue ? Also draw its. diagram.
Answer:
The tongue is a fleshy muscular organ attached at the back to the floor of the buccal cavity, It is free at the front and can be moved in all directions. It has taste buds that detect different tastes of food.
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-6

Question 16.
State the functions of tongue.
Answer:
Functions of Tongue –

  1. We use our tongue for talking.
  2. It mixes saliva with the food.
  3. It helps in swallowing food.
  4. It has taste buds that detect different tastes of food.

Question 17.
What do you mean by tooth decay?
Answer:
Normally bacteria arc present in our mouth. However, if we do not clean our teeth and mouth after eating, many harmful bacteria also begin to live and grow in it. These bacteria break down the sugars present from the leftover food and release acids, This acid gradually damages the teeth. This is called tooth decay. If it is not treated in time, it causes severe toothache and in extreme cases results in tooth loss. Chocolates, sweets, cold drinks and other sugar products are the major culprits of tooth decay. Therefore. one should clean the teeth with a brush or dantun at least twice a day.

Question 18.
What are villi ? What are functions of these villi ?
Answer:
The inner walls of the small intestine have thousands of finger like outgrowths. These are called viii.
Functions of villi –

  1. The villi increase the surface area for absorption of the digested food.
  2. Each villus has a network of thin and small blood vessels close to its surface. Thus the absorbed substances arc transported via the blood vessels,

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 19.
What is diarrhoea ? How it is treated?
Answer:
Sometimes we may have experienced the need to pass watery stool frequently. This condition is known as diarrhoea. It may be caused by an infection, food poisoning or indigestion. Under severe conditions it can be fatal. This is because of the excessive loss of water and salts from the body. It should be treated b’ a doctor immediately. Even before a doctor is consulted the patient should be given plenty of boiled and cooled water with a pinch of salt and sugar dissolved in it. This is called oral Rehydration solution (ORS) which can be got from government hospitals.

Question 20.
Write one similarity and one dissimilarity in the nutrition of amoeba and human being.
Answer:
Similarity and dissimilarity m the nutrition of Amoeba & Human being –
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-7

Question 21.
Why we do Vajrasana and what are phases of its procedure ?
Answer:
To deal with problems like indigestion. acidity, constipation, gas. obesity. etc.. we use a very simple and useful yoga called vajrasana Procedure of Vajrasana –

  1. After f’jr minutes of meal. la down a mat on a plane surface.
  2. Sit down by spreading both legs ahead.
  3. Thereafter, bend left knee such that pas of legs move back and upward.
  4. Now bend the knee of right leg similarly.
  5. Join together the toes of both the legs.
  6. Keep body straight.
  7. Keep your both hands on knee.

Question 22.
Draw a labelled diagram of stomach.
Answer:
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-8

Essay type Questions:

Question 1.
Explain the digestive system of grass – eating animals with a labeled diagram.
Answer:
Grass – eating animals are know as ruminants: for example – cow, buffalo etc. They quickly swallow the grass and store it in a separate part of stomach called rumen. Here the food gets partially digested and is called cud. Later the cud returns to the mouth in small lumps and the animal chews it.
This process is called rumination –

  1. Ruminants have a large sac-like structure between the small intestine and large intestine, called caecum.
  2. The grass is rich in cellulose, a type of carbohydrate.
  3. The cellulose of the food is digested here by the action of certain bacteria.

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-9

Question 2.
Tabulate the number, types and functions of teeth present in buccal cavity of human being.
Answer:
Human buccal cavity contains two Jaws. One is upper side and other is at Lower side, Each Jaw contains 16 (sixteen) teeth. So human buccal cavity contains total 32 teeth. The number. types and functions of these teeth are as follows – Table – Numbers type & functions of human teeth
RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals-10

Question 3.
Explain the digestive system and its working system in human being.
(OR)
Describe the various parts of human alimentary canal with their functions and a suitable diagram.
Answer:
Human digestive System –
The digestive tract and the associated glands together constitute the digestive system in human being. The food components gradually get digested in the various parts of alimentary canal. The main parts. their functions and their working system is as following –
1. Mouth and buccal cavity –
Food is taken into both through the mouth. Our mouth has the salivary glands wich secrete saliva. Tongue mixes saliva with the food during chewing. Food becomes moisten and bolus by mixing saliva. The partial digestion of food starts here. The moistened & bolus food is easy to be swallowed.

2. Oesophagus –
The swallowed food passes into the food pipe. It runs along the neck and the chest. Food is pushed down by movement of the wall of the food pipe. .

3. Stomach –
The stomach is a thick walled bag. The inner lining of the stomach secretes mucous. hydrochloric acid. and digestive juices. The acid kills many bacteria that enter along with the food and makes the medium in the stomach acidic. The digestive juices break down the proteins into simpler substances.

4. Small intestine –
It is highly coiled and is about 6-8 meters long. It receives secretions from the liver and pancreas. Liver secretes bile juice that is stored in a sac called the gall bladder. The bile plays an important role in the digestion of fats. The pancreas releases pancreatic juice which acts on carbohydrates and proteins and changes them into simpler forms. The intestinal juices secreted from walls of small intestine complete the digestion of all components of the food.

5. Large intestine –
It is wider and shorter than small intestine, It is about 1 .5 meters in Length. It is further attached with rectum. Water and some salts arc absorbed here from the undigested food material. The remaining waste passes into the rectum and remains there as semi-solid faeces.

6. Anus –
The faecal matter is removed through the anus from time to time. So. in this way human digestion process gets completed.

[NOTE Please refer to Q. No. 3 of long answer question in text book for diagram]

RBSE Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Question 4.
Explain the process of absorption and assimilation occurring in small intestine.
Answer:
Absorption & assimilation in small intestine – The small intestine is highly coiled and is about 6-8 meters long. It receives secretions from the liver and the pancreas. Besides, its wall also secretes juices. The part digested food reaches the lower part of the small intestine where the intestinal juice completes the digestion of all components of the food.

The digested food passes into the blood vessels in the wall of the intestine. This process in called absorption The inner walls of the small intestine have thousands of finger like outgrowth. These are called villi. These villi increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface.

The surface of the villi absorbs the digested food materials. The absorbed substances are transported via the blood vessels to different organs of the body where the are used to build complex substances such as the proteins required by the body. This process is called assimilation. In the cells, glucose breaks down with the help of oxygen into carbon dioxide and water and energy is released. The food that remains undigested and un – absorbed. then enters into the large intestine.

Question 5.
Mention about those healthy habits by which we can remain healthy.
Answer:
B paving attention to these things we remain healthy –

  1. Before eating and after the meal, wash hand and mouth clean.
  2. Take food on neat and clean place.
  3. Always take fresh and covered meals.
  4. Dine at certain times.
  5. Eat with healthy mind. stay relaxed and keep patience.
  6. Take balanced diet.
  7. Chew food thoroughly.
  8. Take salad of fibrous and green vegetables in meal.
  9. Do not eat more than necessity.
  10. Take all types of food with interest.
  11. Do not talk while eating.
  12. Approximately one hour after a meal. drink water.
  13. Do not waste food. because food grain is gift of God.

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