DAV Class 7 Science Chapter 2 Nutrition in Living Organisms – Animals and Man Question Answer Notes
DAV Class 7 Science Chapter 2 Nutrition in Living Organisms – Animals and Man Question Answer Notes Solution by Expert Science Teacher. DAV Class 7 Science 2st Chapter Nutrition in Living Organisms – Animals and Man for Students of DAV Schools.
Lesson No 2
Nutrition in Living Organisms – Animals and Man
A.) Fill in the blanks.
Answer:
(1) mouth, small intestine (2) Hydrochloric acid (3) liver (4) cud (5) pseudopodia
B.) Match the following:
1. Gall bladder | (a) Bile Juice |
2. Proteins | (b) Cow |
3. Intestinal wall | (c) Absorption |
4. Rumen | (d) False feet |
5. Pseudopodia | (e) Amino acids |
Answers- 1-a, 2 -e,3-c, 4-b,5-d
C.) Tick the correct option.
Answer:
(1) autotrophs (2) heterotroph (3) omnivores (4) liver (5) liver
D.) Answer the following questions in brief.
1.) Define the following terms:
(a) Holozoic nutrition
Answer:
In this form of nutrition, organisms like amoebas and people consume food that may be solid or liquid in consistency.
(b) Alimentary canal
Answer:
It is a long and muscular tube like structure through which food material passes onto other organs.
2.) Give the meaning of the terms:
(a) Assimilation
Answer:
The absorbed food is utilised by the body for growth and formation of body parts. This process is known as assimilation.
(b) Rumination
Answer: The entire process of food entering the mouth and being chewed for digestion is known as rumination.
3.) Name the organs that make up the human alimentary canal.
Answer: The organs that comprise the alimentary canal are- The Mouth / Buccal cavity , the Food pipe /Oesophagus, the Stomach , the Small intestine and Large intestine followed by the Anus.
4.) State two differences between milk teeth and permanent teeth.
Answer:
Milk teeth |
Permanent teeth |
These start developing in humans after 6months of birth | These replace the milk teeth when a child is 6 years old. |
An infant develops 20 milk teeth in total and 10 in both upper and lower jaw | There are 32 permanent teeth , each jaw consists of 16 permanent teeth. |
5.) Name the four types of teeth in the human mouth.
Answer: There are four types of teeth in huma mouth. The incisors, canines , premolars and molars.
6.) State the function of the (a) incisor teeth (b) premolar teeth.
Answer: a) incisor and used for cutting into solid food
b) Premolars are used to grind food material.
7.) State the role of acid in the human stomach.
Answer: It serves as a medium for a specific gastric enzyme-pepsin to carry out is work, apart from this the acid also kills any harmful bacterias that enter the stomach.
8.) State the function of (a) bile juice and (b) pancreatic juice in the human digestive system.
Answer: a) Bile juice neutralizes the excess HCL produced by the stomach
b) pancreatic juices help in easy digestion of carbohydrates, proteins and fats.
Answers- (a) The bile juice plays an important role in digestion of fats.
(b) The pancreatic juice acts on carbohydrates, proteins and fats and breaks them into simpler forms.
E.) Answer the following questions.
1.) Draw a neat, well labelled diagram of the Human digestive system.
2.) Justify the following statements:
(a) Crow is an omnivore.
Answer: Crow not only feeds on animals such as worms it also feeds on fruits hence it is an omnivore.
(b) It is said that the mode of nutrition, in human beings and Amoeba, is quite similar.
Answer: in amoeba the digestive enzymes are released in its vacuoles whereas in humans its digestive juices are released into its stomach, both the organisms then convert the food material to soluble and easily absorbable elements.
3.) Give reasons for the following:
(a) Ingestion of food is difficult without teeth.
Answer: Teeth helping i breaking down the food particles and grinding it finely such that is easier to form a paste like consistency such that it is easily digestible.
(b) If we chew rice, or bread, for a few minutes, it starts tasting sweet.
Answer: On secretion of saliva while the food is being broken down our mouths breaks down starch present in these food into sugar while we keep chewing it.
(c) Bacteria are present in the caecum of ruminants.
Answer: the bacterias present there aid the process of digesting cellulose.
4.) Explain how digested food gets absorbed into the blood.
Answer: When the food passes through the small intestine it absorbs the food. this part contains villi which are finger like projections. these increase the surface area for absorption of food. the food is then passed to blood vessels through the villy and thus the food is transported to all parts of the body through blood
5.) State, in one/two sentence/s each, the various processes involved in nutrition in ruminant animals.
Answer: In ruminants the animals swallow the food and store it in their rumen. The rumen contains microorganism that helps in the digestion of cellulose and other plant materials consumed by the animal. this food is then brought back to their mouth and chewed thoroughly.
6.) Explain ingestion of food, in amoeba, through a diagram.
Answer:
More Extra Questions for Preparation
Q.1) Underline the correct answer.
1.) Animals that eat only plant material.
- Herbivores
- Omnivores
- Carnivores
- None of these.
Q.2) Act of eating food is called
- Digestion
- Absorption
- Egestion
- Ingestion
Q.3) Grinding of food
- Incisors
- Canines
- Premolars
- Molars
Q.4) The undigested food is expelled from the amoeba by process of
- Egestion
- Digestion
- Assimilation
- Ingestion
Q.2) Define the following terms.
1.) Parasitic nutrition.
Answer= The mode of nutrition in which an organism obtains food from some other living organism of different group is known as parasitic nutrition.
2.) Saprotrophic nutrition.
Answer= The mode of nutrition in which an organism obtains its nutrients from dead and decaying plant and animal matter of different group is known as saprotrophic nutrition.
3.) Holozoic nutrition.
Answer= The mode of nutrition in which organism eat food that may be solid or in liquid state . This food is taken into the body and then it is broken down to provide the required nutrition to the body.
Q.3) Name the following.
1.) Covers outer portion of teeth.
Answer= Enamel.
2.) Contains teeth and tongue.
Answer= Buccal cavity.
3.) Flap like structure present at top the wind pipe.
Answer= Epiglottis.
4.) Cud chewing herbivore animal are called
Answer= Ruminants.
5.) Breaking down of complex food into simple forms.
Answer=Digestion.
Q.4) Match the following.
1. Amoeba | a. Mucus |
2. Finger like projections | b.Tearing of food |
3. Protection of stomach | c. Villi |
4. Canines organism | d.Unicellular |
Answer= 1 – d, 2 – c, 3 – a, 4 – b.
Q.5) Fill in the blanks.
1.) Feces are eliminated through anus.
2.) False feet called pseudopodia.
3.) Adult human have 16 teeth in upper jaw 16 in lower jaw.
4.) Tongue is a busy organ.
Q.6) Explain about the muscular organ.
Answer= 1.) Tongue is muscular organ attached to the floor of the buccal cavity.
2.) It is free to move as its front end where it can move in all direction.
3.) The tongue helps in mixing of saliva with food.
4.) Tongue serves as an organ of taste.
Q.7) Explain types of secretion helps for digestion.
Answer=
1.) Secretion from liver= The liver is largest gland in the human body. It is present slightly below the stomach, on the right side. It secretes bile juice that is stored in a bag like structure called gall bladder. Bile juice plays important role in digestion of fats.
2.) Secretion from pancreas= Pancreas is a yellow leaf shaped gland located just below the stomach. It secretes pancreatic juice; this juice acts on carbohydrates, proteins and fats and breaks them into simpler forms.
3.) Secretion from the small intestine= The inner wall of the small intestine, itself secretes the intestinal juice. This juice digests carbohydrates, proteins and fats.
Q.8) Draw a flow chart for nutrition in amoeba.
Q.9) State whether the following statements are true or false explain with reason if the answer is false.
1.) Cud chewing herbivore animals are called ruminants.
Answer= true
2.) Pancreatic juice plays an important role in digestion of fats.
Answer= False, bile juice plays an important role in digestion of fats.
3.) The stomach is the widest part of the alimentary canal.
Answer= True
4.) Molars are used for tearing of food.
Answer= False, canines are used for tearing of food.