CBSE Class 10 Science Biology Nutrition Assignment

Read and download free pdf of CBSE Class 10 Science Biology Nutrition Assignment. Get printable school Assignments for Class 10 Biology. Standard 10 students should practise questions and answers given here for Chapter 6 Life Processes Biology in Grade 10 which will help them to strengthen their understanding of all important topics. Students should also download free pdf of Printable Worksheets for Class 10 Biology prepared as per the latest books and syllabus issued by NCERT, CBSE, KVS and do problems daily to score better marks in tests and examinations

Assignment for Class 10 Biology Chapter 6 Life Processes

Class 10 Biology students should refer to the following printable assignment in Pdf for Chapter 6 Life Processes in standard 10. This test paper with questions and answers for Grade 10 Biology will be very useful for exams and help you to score good marks

Chapter 6 Life Processes Class 10 Biology Assignment


Notes on Class 10 Science Nutrition :-

1.1 Nutrition :  “Nutrition” is a process of intake as well as utilization of nutrients by an organism. It is the process of breakdown of nutrients into smaller molecules and their absorption. Food provides us nutrition and energy. It contains different types of nutrients in varying amounts according to the need of our body.

1.1 (a) Nutrients : These are the substances required by our body for its growth, repair, work and maintenance of the body. Different types of nutrients are carbohydrates, fats, proteins, vitamins, mineral etc. Our daily energy need may vary according to our occupation, age, sex and under some specific conditions.

1.2 Modes Or Nutrition : There are several modes of nutrition on the basis of which organisms are classified as follows :

Nutrition :
Autotrophic - They are able to synthesize - 
Heterotrophic- They are not able to synthesize their own food. their own food.
1.2 (a) Autotrophic :
(Auto = self, trophic = food) It is a mode of nutrition in which organisms prepare their own food. Inorganic molecules like CO2 and H2O are converted into organic molecules like carbohydrates in the presence of sunlight and chlorophyll. e.g. Green plants. Autotrophs are further categorized. as :
(i) Photoautotroph : Those which utilize sunlight for preparing their food
(ii) Chemoautotroph : Those which utilize chemical energy for preparing their food.
1.2 (b) Heterotrophic : (Hetero = different ; trophic = food) It is a mode of nutrition in which organisms derive their food fro some other animals or plants. They cannot prepare their own food e.g. human being. Heterotrophs are  further categorized depending on the nature of food they consume :
(i) Herbivores : Animals which eat only plants, e.g. Cow, goat etc.
(ii) Carnivores : They feed on flesh of other animals, e.g. Lion, vulture etc.
(iii) Omnivores : T hey feed on plants and animals both e.g. Dog, human etc.
(iv) Detritivores : Feed on detritus or dead organic remains, e.g. Earthworm etc.
(v) Sanguivorous : Feed on blood e.g. Leech, female mosquito etc.
(vi) Frugivorous : Feed on fruits, e.g. Parrot etc.
(vii) Insectivores : Feed on insects, e.g. Bats etc.
1.2 (c) On the Basis of Mode of Feeding Organisms are Categorised As :
(i) Holozoic : They ingest mostly solid but sometimes liquid food. e.g., Amoeba, human etc.
(ii) Saprotrophic : they absorb organic matter from dead and decaying organisms with the help of their enzymes. e.g., Bacteria, fungi etc.
(iii) Parasitic : They derive their nutrition from other living plants or animals e.g. Plasmodium round worms etc.
Nutrition can be divided into two categories on the basis of occurrence:
Nutrition in plants
Nutrition in animals
1.3 Nutrition in Plants:
• Plants are autotrophic in nature. They prepare their own food hence they are called as producers.
• They contain a green pigment called chlorophyll which can entrap solar energy which is then converted into chemical energy in the form of food and the process is called as “Photosynthesis”.
1.3 (a) Photosynthesis :
(i) Definition : The synthesis of organic compounds like glucose from simple inorganic molecules like CO2 and H2O by the cells of green plants having chlorophyll in the presence of sunlight is called as photosynthesis.
(ii) Equitation of photosynthesis : Photosynthesis is a two step process.
6CO2 + 12H2O  →  C6H12O6 + 6O2 + 6H2O
(A) Light reaction : AT, NADPH2 and O2 are produced.
(B) Dark reaction : CO2 & H2O are converted into glucose.
• Photosynthesis essentially requires two things :
1.3 (b) Sunlight :
• For plants sun the basis source of radiant energy.
• Plants utilize the light in the visible region of solar spectra (electromagnetic spectrum) which comes under the range of 390 nm - 780 nm.
• Visible region consists of white light which is a mixture of 7 lights of different wavelengths.
• Maximum photosynthesis occurs in red region.
• There is minimum photosynthesis in green region because green parts of plants reflect whole of the green light.
1.3 (c) Chlorophyll :
These are the green pigments present in chloroplast. They are found in green leaves in a maximum amount as well as in other green aerial parts of plant. There are six different types of chlorophyll, they are chlorophyll a,b,c,d,e and bacteriochlorophyll, amongst them chlorophyll a and chlorophyll b are the most commonly occurring chlorophylls.
• Besides chlorophyll certain other pigments are also present in plants like.
(i) Carotenes : Orange in colour e.g. Carrot.
(ii) Xanthophylls : Orange yellow in colour e.g. Maize.
(iii) Phycobilins : Different colour like red, violet e.g. Blue-green algae, brown algae etc.
1.3(d) Raw Materials of Photosynthesis :
(i) Carbondioxide : Terrestrial plants obtain carbon dioxide from the atmosphere through the small openings present on leaves called as stomata. ‘Stomata’ are the small pores present on the surface of leaves.
They help in exchange of gases and water. Stomata opening is guarded by the presence of guard cells (kidney shaped). Aquatic plants obtain CO2 dissolved in water through their general body surface so they perform more photosynthesis than terrestrial plants.
(ii) Water : Plants absorb water from the soil by the process of osmosis.
This water is transported to leaves by a special type of tissue called as xylem.
• Plants utilize carbon dioxide during photosynthesis, the intensity of light at which amount of CO2 used during photosynthesis becomes equal to the amount of CO2 released during respiration by plants in called as Compensation point.
• Compensation point occurs at low light intensity that is during morning and during evening hours.
1.3 (e) Site Photosynthesis :
Site of photosynthesis is different in prokaryotes and eukaryotes.
• In prokaryotes : Photosynthesis occurs in lamellar chromatophores.
• In eukaryotes : Photosynthesis occurs in chloroplast.
• Exception : Fungi ( It lacks chlorophyll so no photosynthesis occurs here).
• In higher plants chloroplast in the main site of photosynthesis.
• Chloroplast is also called as green plastid.
• Plastid was first observed by Haeckel.
• Plastids are of 3 different types on the basis of pigments present in them.
(i) Leucoplast : White in colour, found in underground parts, lacks and coloured pigment. Helps in storage of protein (Aleuroplst), oil (Elaioplast), starch (Amyloplst)
(ii) Chloroplast : Colour other than green found in aerial parts on the plants
(iii) Chloroplast : Contain green pigment, called as chlorophyll.
• Chloroplast was discovered by Schimper.
• Number of chloroplasts is variable in different species of plants.
• In lower plants like algae they are 1 or 2 number.
• In higher plants their number varies from 40 -100 per palisade cell or more.
• Chloroplast also have variable shapes, for example cup shaped, ribbon shaped etc. in algae while it is discoidal in higher plants.
• A typical structure of chloroplast is a double membranous structure having two parts.
(i) Grana : It is a lamellar system consisting of stacks of granum lamella each bounded by a membranous box called as thylakoid. They are 40 - 60 per cell. Number of thylakoids per grana is 50 or more Chlorophyll molecules are found inside the thylakoid membrane where they trap solar energy in the form of small energy packets called ‘photon’ or ‘quanta’. Grana are interconnected to each other by a channel called as stroma lamellae or Fret’s channel.
(ii) Stroma : It is a non pigmented proteinaceous matrix in which grana remain embedded. It contain enzymes for dark reaction.
1.3 (f) Mechanism of Photosynthesis :
(i) Light reaction :
• It is also called as photochemical process.
• It was discovered by ‘Robert Hill’ therefore it is also called as Hill’s reaction
• Site : Grana of chloroplast.
• Raw materials : Light and water.
• Regulation : This process is regulated by chlorophyll molecules.
• It consist of 3 steps :
(A) Photo excitation of chlorophyll molecule : During this process chlorophyll molecule receives sunlight in the form of small energy bundles called as photons and become excited to higher energy level.
(B) Photolysis : It is also called as photoxidation of water, this takes place in presence of Mn+2 and Cl- ions.
O2 is liberated as by product and H+ ions are used for reduction of NADP
(C) Photophosphorylation : During this process ATP are produced. It takes place in quantasomes.
Mg+2 ions and inorganic phosphate is required to convert ADP ATP, ADP + iP  ATP.
(ii) Dark reaction :
• It is also called as thermo chemical reaction.
• It was discovered by Melvin calving and benson therefore it is also called as Calving cycle Site = Stroma of chloroplast.
• Raw materials : They require CO2, NADPH2, ATP and Enzymes.
• Regulated by : Light reaction and enzymes.
It involves three basic steps :
(A) Carboxylation : In this step CO2 is captured by CO2 acceptors like RUBP (C3 Plants) PET (C4Plants) with the help of carboxylase enzyme i.e. RUBISCO & PEPCO respectively.
(B) Synthesis : This phase cap true CO2 is assimilated into glucose in the presence of phosphatase and isomerease enzymes and RUBP is regenerated back.
(C) Regeneration of RUBP

1.4 Factors Affecting Photosynthesis : 

1.4 (a) Light ;
Normally plants utilize sunlight but marine algae can perform photosynthesis even in the moon light. Plants can also perform photosynthesis in the artificial lights.
• Highest rate of photosynthesis : Red light
• Minimum photosynthesis : Green light
• Very high light intensity can cause reduction in the rate of photosynthesis by causing
(i) Decrease in transpiration rate
(ii) Denaturation of chlorophyll molecule
1.4 (b) Temperature :
Optimum range = 25° C to 30° C
It ranges from 10° - 40° C
In some forms like algae of hot spring 60° - 70° is normal
1.4 (c) Carbon dioxide :
It is the first limiting factor 0.03 - 0.1% is present in the atmosphere concentration of CO2 rate of photosynthesis.
above 0.9%
between 0.1 to 0.9%, it is constant and it is called as saturation point.
1.4 (d) Oxygen :
O2 acts as competitive inhibitor of CO2. Over concentration of O2 stops photosynthesis.
1.4 (e) Chlorophyll :
Chlorophyll content is directly proportional to rate of photosynthesis.
No photosynthesis occurs in etiolated cells, In variegated leaves it occurs only at places where chlorophyll is present. 

1.5 Significance Of Photosynthesis : Photosynthesis is a boon to the nature and to the human beings. It has following significance :

(i) Production of food material
(ii) Atmospheric control and purification of air.  

MCQ Questions for Class 10 Science Nutrition :-

Question : The raw materials for photosynthesis are
(A) CO2 & O21 (B) sunlight and CO2 (C) water and chlorophyll (D) CO2 and water.
Answer : D
Question : Most of the photosynthesis (80%) which takes place on this earth is carried out by
(A) green plants on land (B) algae present in fresh water
(C) algae found in ocean (D) algae present in ocean and fresh water sources.
Answer : D
Question : Which of the following ahs no digestive enzyme ?
(A) Saliva
(B) Bile
(C) Gastric juice
(D) Intestinal juice
Answer : B
Question : Plants are green in colour because
(A) they absorb green light only
(B) they reflect green light
(C) they absorb green light but reflect all other lights
(D) none of the above are correct.
Answer : B
Question : Full name of N ADP is
(A) Nicotinamide dinucleotide phosphate
(B) Nicotineadenine dinuceotide phosphate
(C) Nicotinamide adenine dinucleotide phosphate
(D) None of the above
Answer : C
Question : Wavelength of visible light is
(A) 200 - 400 nm
(B) 400 - 700 nm
(C) 700 - 900 nm
(D) 100 - 200 nm
Answer : B
Question : The presence of sugar in onion leaves can be tested with
(A) iodine (B) copper sulphate solution
(C) lime water (D) benedict’s solution
Answer : D
Question : Chemical reaction takes place during dark reaction of photosynthesis is
(A) photolysis
(B) hydrolysis
(C) carbon dioxide is bonded with RUBP
(D) nitrogen fixation
Answer : C
Question : Dark reaction and light reaction of photosynthesis takes place in
(A) stroma and grana of chloroplast respectively
(B) grana and stroma of chloroplast respectively
(C) grana only
(D) stroma only
Answer : A
Question : CO2 acceptor during dark reaction of photosynthesis is
Answer : A

Question. Where are proteins first digested in the alimentary canal ?
(a) small intestine
(b) oesophagus
(c) mouth
(d) stomach
Answer : D

Question. The inner lining of stomach is protected by one of the following from the harmful effect of hydrochloric acid. This is :
(a) pepsin
(b) mucus
(c) saliva
(d) bile
Answer : B

Question. Which part of alimentary canal receives bile from the liver ?
(a) oesophagus
(b) small intestine
(c) stomach
(d) large intestine
Answer : B

Question. Which of the following component of our food is digested by an enzyme which is present in saliva as wellas in  pancreatic juice ?
(a) proteins
(b) fat
(c) minerals
(d) carbohydrate
Answer : D

Question. If the saliva is lacking in salivary amylase, then which of the following processes taking place in the buccal cavity will be affected ?
(a) proteins breaking down into amino acids
(b) starch breaking down into sugars
(c) fats breaking down into fatty acids and glycerol
(d) intestinal layer breaking down leading to ulcers
Answer : B

Question. Which of the following are the correct functions of two components of pancreatic juice trypsin and lipase ?
(a) trypsin digests proteins and lipase carbohydrates
(b) trypsin digests emulsified fats and lipase proteins
(c) trypsin digests starch and lipase fats
(d) trypsin digests proteins and lipase emulsified fats
Answer : D

Question. The oxygen liberated during photosynthesis by green plants comes from :
(a) glucose
(b) water
(c) carbon dioxide
(d) chlorophyll
Answer : B

Question. Which of the following is an incorrect statement ?
(a) energy is essential for life processes
(b) organisms grow with time
(c) movement of molecules does not take place among cells
(d) organisms must repair and maintain their body
Answer : C

Question. The internal energy (cellular energy) reserve in autotrophs is :
(a) proteins
(b) fatty acids
(c) glycogen
(d) starch
Answer : D

Question. Which of the following events does not occur in photosynthesis ?
(a) conversion of light energy into chemical energy
(b) reduction of carbon dioxide to carbohydrates
(c) oxidation of carbon to carbon dioxide
(d) absorption of light energy by chlorophyll
Answer : C

Question. The opening and closing of the stomatal pores depends upon :
(a) oxygen
(b) water in guard cells
(c) temperature
(d) concentration of CO2 in stomata
Answer : B

Question. Most of the plants absorb nitrogen in one of the following forms. This is :
(a) proteins
(b) nitrates and nitrites
(c) urea
(d) atmospheric nitrogen
Answer : B

Question. The first enzyme to mix with food in the digestive tract is :
(a) pepsin
(b) cellulose
(c) amylase
(d) trypsin
Answer : C

Question. Which of the following is the correct statement ?
(a) heterotrophs synthesise their own food
(b) heterotrophs utilize solar energy for photosynthesis
(c) heterotrophs do not synthesise their own food
(d) heterotrophs are capable of converting carbon dioxide and water into carbohydrates
Answer : C

Question. In which of the following groups of organisms the food material is broken down outside the body and then absorbed ?
(a) Mushroom, Green plants, Amoeba
(b) Yeast, Mushroom, Bread mould
(c) Paramecium, Amoeba, Cuscuta
(d) Cuscuta, Lice, Tapeworm
Answer : B

Question. Which of the following is the correct sequence of parts as they occur in the human alimentary canal ?
(a) Mouth → Stomach → Small intestine → Oesophagus → Large intestine
(b) Mouth → Oesophagus → Stomach → Large intestine → Small intestine
(c) Mouth → Stomach → Oesophagus → Small intestine → Large intestine
(d) Mouth → Oesophagus → Stomach → Small intestine → Large intestine
Answer : D

2.1 Nutrition In Animals :

• Animals have highly evolved digestive mechanism that includes two basic components :
• Alimentary canal : Long, hollow, tubular structure consisting of various organs for digestion.
• Digestive glands : They secrete enzymes/hormones which help in digestion.
• Digestion in animals consist of following steps :
• Ingestion : The process of intake of food.
• Digestion : It is the breakdown of large and complex molecules into simpler, smaller and soluble forms.
• Absorption : Taking up of the digested food through intestinal wall to blood.
• Assimilation : In this process absorbed food in taken by body cells.
• Egestion : The process by which undigested matter is expelled out.
• Digestive system is regulated by various hormones secreted by some endocrine glands.
• Alimentary canal was first of all developed in the phylum Platyelminthes but only mouth was present in them.
• Coiled and well developed alimentary canal was developed in annelida till mammals.

2.2 Nutrition In Lower Animals : 

2.2 (a) Nutrition in Amoeba :
It is a unicellular organism living in water.
• Mode of nutrition of holozoic.
• The process of obtaining food is the phagocytosis (cell eating)
• Steps involved in digestion of amoeba are :
(i) Ingestion : Since it is unicellular so a single cell is responsible for carrying out all the vital activities. Food is ingested with the help of pseudopodia. Animal engulfs the food particle lying near it by forming pseudopodia around it and forming a food vacuole while is considered at its temporary stomach.
(ii) Digestion : The enzymes from surrounding cytoplasm enter the food vacuole and break down the food into smaller & soluble forms.
(iii) Absorption : The digested food is now absorbed by cytoplasm by simple diffusion and then the food vacuole disappear.
(iv) Assimilation : The food absorbed in amoeba is used to obtain energy from respiration, for its growth and reproduction.
(v) Egestion : Undigested food is thrown out of the cell.
2.2 (b) Nutrition is Grasshopper :
• It has a well developed digestive system having an alimentary canal and digestive glands.
• The various organs of digestive system of grasshopper are Mouth Oesophagus Crop Gizzard Stomach Ileum Colon Rectum.
Mouth→  Oesophagus→  Crop→  Gizzard→  Stomach→  Ileum→  Colon→  Rectum.
• Glands associated with it are :
(i) Salivary glands (ii) Hepatic caeca
• Digestive system of a grasshopper can be divided into three parts.
(i) Foregut : mouth to gizzard
(ii) Midgut : gizzard to ileum (actual stomach)
(iii) Hindgut: stomach to anus.
• The process involves:
(i) Ingestion : If feeds on green leaves so it takes food through its mouth with the help of it’s forelegs and mouth parts.
(ii) Digestion:
(A) It starts from the mouth.
(B) A pair of salivary glands secretes saliva and release it into the mouth through the salivary duct.
(C) Saliva mixed with food and lubricates and soften the food.
(D) Digestion of starch begins here.
(E) This slightly digested food enters into the crop through a food pipe i.e. esophagus.
(F) Crop stores the food temporarily.
(G) Now the food moves to gizzard. Here it is finally crushed and masticated an then moves to stomach.
(H) In stomach hepatic caeca release its secretions in the form of digestive enzymes, thus the food is then completely digested at this site.
(iii) Absorption : The digested food moves to small intestine (ileum) and absorbed through its walls.
(iv) Assimilation : Nutrients are assimilated whenever required by the cells for the fulfillment of the growth, energy and repair of the body.
(v) Egestion : Undigested food is then passed through hindgut (where H2O absorbed) and expelled out through anus in the form of elongated dry faecal pallets.
• The excretory organ of the grasshopper is malphigian tubules present at the junction of hindgut and midgut.

2.3 Nutrition In Humans :
• Humans have highly evolved and complicated digestive system consisting of an alimentary canal and different types of digestive glands.
• Alimentary canal consist of following organs :

2.3 (a) Mouth :
It is small slit through which food is ingested.
2.3 (b) Buccal Cavity :
Mouth opens into a chamber called as buccal cavity. Roof of buccal cavity is called hard palate. At the floor of this cavity thick muscular structure is present called tongue. it helps in chewing swallowing, testing and speaking. Tongue has various types of papilla having taste buds.
• Jaws present in buccal cavity are provided with four different types of teeth :
(i) Incisors : For cutting
(ii) Canines : For tearing
(iii) Premolars : For grinding
(iv) Molars : For grinding
• Dental formula of humans :
(A) Milk teeth →These are temporary, arise at 6 - 11 month age, 20 in
 Half upper jaw /  Half lower jaw  = 2102 / 2102
(B) Permanent teeth→   arise at   6 – 12 years, 32 in number
 Half upper jaw /  Half lower jaw  = 2123 / 2123
• Three pairs of salivary glands are found in mouth which release their secretions into the buccal cavity.
2.3 (C) Oesophagus :
Also called as food pipe. It leads the food from mouth to stomach, Oesophagus has highly muscular walls, no digestion occurs here.
2.3 (b) Stomach :
It is a ‘J’ shaped bag present on left side of abdomen. It contains several branched and butular glands present on the inner surface of its wall, which secret gastric juice.
2.3 (e) Small Intestine :
It is a coiled and narrow tube having 3 regions : Duodenum , jejunum, ileum.
• On the inner wall of small intestine numerous finger like projections are found which are called as villi, they increase the surface area of absorption.
• Duodenum is proximal part of small intestine receives secretion from liver and pancreas.
2.3 (f) large Intestine :
Small intestine opens into large intestine from w here the undigested food material is passed to anus through rectum. It is divided into three parts:
(i) Caecum (ii) Colon (iii) Rectum
2.3 (g) Digestive Glands :
(i) Salivary glands : 3 pairs of salivary glands are found in mouth cavity. It helps in chemical digestion. They secret at enzyme called salivary amylase or ptyalin. It helps in digestion of starch.
(ii) Gastric glands : Present in stomach. They secret hydrochloric acid, protein digesting enzymes and mucus.
(iii) Liver : It is the largest gland, secrets bile into the small intestine.
Bile contains bile juice and bile pigments. Bile is alkaline in nature and it is temporarily stored in gall bladder and helps in digestion of fats, it also helps in absorption fats.
(iv) Pancreas: It lies parallel to and below the stomach. It secrets pancreatic juice into small intestine. Pancreatic juice contains tyrosine and pancreatic amylase. Besides these 2 enzymes pancreas secretes 2 hormones also i.e. :- insulin and glucagons so it has both exocrine as
well as endocrine functions. Both bile and pancreatic juice are released into the duodenum by a common duct.  

MCQ Questions for Class 10 Science Nutrition :-

Question : Compensation point refers to the intensity of light at which
(A) Rate of respiration = rate of photosynthesis
(B) Rate of respiration> rate of photosynthesis
(C) Rate of respiration < Rate of photosynthesis
(D) None of the above is correct
Answer : A
Question : Among the following which is a parasitic plant ?
(A) Plasmodium
(B) Cuscuta
(C) Amoeba
(D) Rhizobium
Answer : B
Question : The nutrition in mucor is
(A) parasitic
(B) autotrophic
(C) saprophytic
(D) holozoic
Answer : C
Question : In amoeba the digestion is intracellular because
(A) amoeba is unicellular
(B) amoeba is multicellular
(C) amoeba is found is pond
(D) amoeba is microscopic animal
Answer : A
Question : Digestion of food in human starts from
(A) duodenum
(B) small intestine
(C) mouth
(D) large intestine
Answer : C
Question : The digestion of food is completed in the
(A) ileum
(B) duodenum
(C) stomach
(D) large intestine
Answer : A
Question : The most important function of villi in the small intestine is
(A) to provide strength to the intestine
(B) to provide space for capillaries and lacteals
(C) to provide increased surface area for absorption of digested food
(D) to provide habitat for bacteria
Answer : C
Question : Which of the following sections does not contain enzymes ?
(A) Bile
(B) Pancreatic juice
(C) Intestinal juice
(D) Saliva
Answer : A
Question : Chewing is an example of
(A) chemical digestion
(B) mechanical digestion
(C) involuntary action
(D) hydrolysis
Answer : B
Question : The final product of digestion of carbohydrates and proteins are
(A) glycerol and amino acid respectively
(B) glucose and amino acids respectively
(C) amino acids and glycerol respectively
(D) amino acids and glucose respectively
Answer : B

3.1 Intestinal Glands :

They secrete intestinal juice and mucus.



3.1 (a) Digestive System :

This system involves following processes :

(i) Ingestion : Intake of food is done through mouth, food is then chewed and masticated and sent to esophagus through pharynx by swallowing.

(ii) Digestion : Saliva secreted in buccal cavity starts digestion of starch into maltose. This partly digested food is then passed to stomach by esophagus through peristaltic movement. Food is churned in stomach for about three hours and broken down into smaller pieces. Due to presence of hydrochloric acid, medium of stomach becomes acidic. In acidic medium protein digestive enzyme pepsin breaks down proteins into peptones. Gastric Lipase is also secreted here which partially breaks down lipids.

• Secretion of gastric juice is stimulated by the sight, smell or thought of food.

• Now the partly digested food moves to small intestine i.e. in the duodenum. Duodenum receives the secretion from liver and pancreas through a common duct they are bile and pancreatic juice, and alkaline in nature. So the digestion and emulsification of facts occurs at this place.

• Here in the duodenum fats are emulsified by bile, remaining proteins are digested by trypsin and starch by pancreatic amylase.

NOTE : Duodenal wall secretes bicarbonate ions which make the medium alkaline.

• This partially digested food now enters in the ileum where intestinal juice i.e. “Succus entericus” is secreted. At this place digestion is completed.

Carbohydrates→  Glucose

Proteins  →Amino acids

Fats →  Fatty acids and glycerol 

(iii) Absorption : After digestion molecules are broken down into simpler water soluble forms now they are to be utilized, so they pass through the wall of small intestine which contains blood capillaries and enters into the blood. For absorption of fat lymph capillaries are present called as lacteals.

NOTE : Wall of small intestine have tiny finger like projections called villi, they increase the surface area for absorption.

(iv) Assimilation : The process of utilizations of food is called assimilating. The nutrients dissolved in blood are carried to all parts of the body where they are utilized.

(A) For building up and replacement of cells.

(B) For obtaining energy. This energy is released by the process of oxidation during respiration.

(v) Egestion : The undigested food is then collected in large intestine where water is absorbed and remaining waste is expelled out or egested through anus.


MCQ Questions for Class 10 Science Nutrition :-


Question : In amoeba the digestion of food is

(A) extracellular
(B) intracellular
(C) intercellular
(D) none of the above

Answer :  B

Question : Through mastication of food is essential because
(A) mastication of food makes the teeth stronger
(B) it makes the process of swallowing the food easier
(C) by this process bigger pieces of food are broken down into smaller pieces.
(D) bigger pieces of food are broken down into smaller pieces and saliva is properly mixed with it

Answer :  D 

Question : The wave of contractions that pushes the food through the alimentary canal is called
(A) peritoneum
(B) peristalsis
(C) cyclosis
(D) polarisation

Answer :  B

Question : In amoeba absorption of the digested nutrients occurs in
(A) contractile vacuole
(B) plasma membrane
(C) cytoplasm
(D) pseudopodia

Answer :  A

Question : Coiled and well developed alimentary canal first developed in
(A) Protozoans
(B) Mammals
(C) Arthropods
(D) Poriferans

Answer :  C

Question : Digestion of starch starts from
(A) stomach
(B) intestine
(C) esophagus
(D) mouth

Answer :  D

Question : The path taken by food material after ingestion is represented by
 (A) Mouth Pharynx Oesophagus Stomach
(B) Mouth Pharynx Oesophagus Small Intestine
(C) Mouth Oesophagus Stomach Pharynx
(D) Oesophagus Mouth Pharynx Stomach

Answer :  A

Question : Teeth involved in cutting of food material are called
(A) canines
(B) incisors
(C) molars
(D) premolars

Answer :  B

Question : Ptyalin enzyme is secreted by
(A) salivary glands
(B) mouth
(C) esophagus
(D) stomach

Answer :  A

Question : Villi are present on
(A) stomach
(B) large intestine
(C) small intestine
(D) mouth

Answer :  C 



1 Give the appropriate terms to the following statements

a. Any substance taken into the body for purpose of providing nutrition.

b. Conversion of complex food particles into simpler food particles in presence of enzymes.

2 Name the enzymes found in the pancreatic juice.

3 What are the raw materials used in photosynthesis.

4 What is the role of gastric HCl ?

5 What is life process? Give some examples for life process?

6 Name the type of nutrition

a. Fungi like bread mould, yeast, mushroom breakdown the food materials outside the body and absorb it.

b. Cuscuta, lices and ticks derive nutrition from plants or animals without killing them




7 How does Amoeba intake food? Briefly mention.

8 Which digestive secretion does not contain any enzyme but is very important in the process of digestion. Comment on it.

9 a) What are the major events occurring during the process of photosynthesis?

b) Name the energy transformation taking place in the process of photosynthesis.


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