Chapter NUTRITION

1 – Food Supplying System

Conceptual understanding

1. Write differences between

a) autotrophic nutrition – heterotrophic nutrition
b) Ingestion − digestion
c) Light reaction − dark reaction
d) Chlorophyll – chloroplast

a. Autotrophic Nutrition Heterotrophic Nutrition

1. The nutrition in which an organism 1. The nutrition in which an organism cannot

synthesizes its own food from simple synthesize its own food and depends on
inorganic compounds is called other living beings for food is called
autotrophic nutrition. heterotrophic nutrition.
2. It is of two types - photo autotrophic 2. It is of different types – saprotrophic
nutrition and chemoautotrophic nutrition, parasitic nutrition and holozoic
nutrition. nutrition.
3. Photoautotrophs use light as a 3. Saprophytes derive their nutrients by
source of energy and chemo decomposing organic matter, parasites
autotrophs use chemical energy for obtain their nutrients by living in or on the
the preparation of food. body of another organism (host) and in
holozoic nutrition organism ingests the
food and digests it.

Eg: Green plants, algae, sulphur Eg: Bacteria, fungi, leech, plasmodium
bacteria etc., deer, lion, humans etc.,

b. Ingestion Digestion

1. The process by which food is 1. The process in which large complex

taken into the alimentary canal molecules present in the ingested food are
(eating) is called ingestion. It is broken down into simpler forms in the
different in different animals alimentary canal is called digestion.

2. It is a physical process. 2. It includes mechanical processes such as

chewing, churning and grinding food as well
as chemical action of digestive enzymes and
other substances (bile, acid etc) on food.
3. Occurs in oral or buccal cavity. 3. Occurs in oral cavity, stomach and small
intestine.

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c) Light reaction Dark reaction

1. It is also known as photo chemical 1. It is also known as biosynthetic phase.

phase.

2. It occurs only in presence of light. 2. It occurs in presence and also in absence

of light.
3. It occurs in the thylakoid membranes 3. It occurs in the stroma of chloroplast.
of the chloroplast.

4. In this phase photolysis of water 4. In this phase reduction of carbon dioxide

occurs. to carbohydrate takes place.

5. The products of light reactions are 5. Product of dark reactions is glucose.

ATP, NADPH and molecular oxygen.

6. These reactions are also called as 6. It is also called as Calvin Cycle.

Hill’s reactions.

d) Chlorophyll Chloroplast

1. It is a green colored pigment. 1. It is a cell organelle (green plastid)

present only in plant cells.

2. It is situated in thylakoid 2. They are present in green leaves

membrane. and other green regions of the
plant.

3. It is an organic molecule with 3. They are ovoid or disc shaped

one atom of magnesium and its structures bounded by two
structure is similar to the haem semipermeable membranes.
of haemoglobin.

4. They trap the solar energy. 4. Chloroplast prepares the food

through the process called
photosynthesis.

NOTE: Pelletier and Caventou extracted “Chlorophyll” and named it. Julius Von Sachs
observed that chlorophyll is found in chloroplast of a cell. Arnon isolated
chloroplast from plant cell.

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2 Give reasons
a) Why photosynthesis is considered as the basic energy source for most
of the living world?
Ans:
1. Plants are capable of synthesizing food (carbohydrate) by utilizing energy
present in light from simple inorganic compounds like CO2, water and
minerals.
2. The food produced by plants forms source of energy for all animals and
humans.
3. It is the only process which adds oxygen to atmosphere which makes our
living possible.
4. Besides providing energy as food, photosynthesis has led to the formation of
large reserves of energy in the form of coal, petroleum, wood and biomass.

b) Why is it better to call the dark phase of photosynthesis as a light

independent phase?
Ans:
1. Dark phase of photosynthesis does not require the presence of light i.e it
does not depend on light.
2. It occurs in the presence or absence of light, so it is also called as light
independent phase.

c) Why is it necessary to destrach a plant before performing any

experiment on photosynthesis?
Ans:
Glucose, the main product of photosynthesis is stored in plants in the form of
starch. Starch formation is taken as an index for photosynthesis. To get
better results from related experiment, it is necessary to destarch a plant
before performing any experiment on photosynthesis.

d) Why is it not possible to demonstrate respiration in green plant kept in

sunlight?
Ans:
1. When the plant is kept in sunlight, it performs photosynthesis and respiration
simultaneously.
2. The oxygen evolved in photosynthesis becomes raw material for respiration.
3. The rate of respiration will be measured by calculating the amount of oxygen
absorbed from the environment.
4. But, it is not possible when the plant is kept in sunlight because the oxygen
released during photosynthesis is utilized in respiration. So the experiments
on respiration are done during night when there is no sunlight.
3. Give examples
a) Digestive enzymes: Pepsin, Trypsin, Amylase, lipase
b) Organisms having heterotrophic nutrition: Animals, humans, fungi.
c) Vitamins: Vitamin A (Retinol),Vitamin B1(Thiamine), Vitamin C(Ascorbic
acid), Vitamin D (Calciferol) etc.
d) Food deficiency diseases: Kwashiorkor, Marasmus

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4. Where do plants get each of the raw materials required for photosynthesis?
Ans:
1. Green plants get carbon dioxide through stomata of leaves.
2. Water along with minerals is absorbed from the soil by root system.
3. Sunlight is trapped by the leaves with the help of chlorophyll and accessory
pigments.
4. Thus, plants make their own food from carbon dioxide and water by using
sunlight in the presence of chlorophyll is called photosynthesis.

5. Explain the process of photosynthesis with the help of flow chart.

Ans:
1. Photosynthesis is the process by which green plants make their food from
carbon dioxide and water by using sunlight in the presence of chlorophyll.

2. Equation for photosynthesis:

light
6CO2 + 12H2O 
chlorophyll
C6H12O6 + 6O2 + 6H2O

Flow Chart

Sun Light
Oxygen given off into air
Water Chlorophyll traps
absorbed from light energy to Water
the roots make food Converted
Sugar Starch
Carbon dioxide Stored food in other
enters through the parts of the plant turns
stomata of the leaves iodine dark blue.

Photosynthesis

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3. During photosynthesis several events occur in the chloroplasts of leaves.

They are
a. Conversion of light energy to chemical energy.
b. Photolysis of water (splitting of water molecule).
c. Reduction of carbon dioxide to carbohydrate.
4. Light is required for several events of the photosynthesis (Light phase) while
other reactions continue in absence of light (dark phase).
5. Glucose, water, and oxygen are the end products of photosynthesis.

6. Name the three end products of photosynthesis.

Ans: The end products of photosynthesis are glucose, water and oxygen. Glucose is
converted to starch and stored in plant parts.

7. What is the connecting substance between light reaction and dark reaction?

Ans: Energy rich molecules ATP and NADPH synthesized during light reactions are the
connecting substances between light reaction and dark reaction.

8. Most leaves have the upper surface more green and shiny than the lower
ones. Why?

Ans: 1. Mesophyll tissue in leaf is differentiated into upper palisade parenchyma and
lower spongy parenchyma.
2. More number of chloroplasts are present in the palisade tissue and it
absorbs more light energy than spongy tissue.
3. This is the reason why leaves have the upper surface more green than the
lower one.

9. Explain the structure of chloroplast with a neatly labeled sketch.

Ans:
1. Green plants consist of special membrane bound organelles called
chloroplasts.
2. Chloroplasts occur in the mesophyll cells of the leaves.
3. Typical chloroplasts are ovoid or disc shaped and consists of three
membranes. It is bounded by two semi permeable membranes and the third
membrane is thylakoid membrane.
4. The intermediary fluid filled portion of the chloroplast is called stroma. It
consists of enzymes necessary for photosynthesis.
5. The stacks of thylakoid membranes stalked one above the other like a pile of
coins is called grana.
6. The adjacent grana are inter connected by stroma lamellae.
7. The photosynthetic pigments chlorophylls and other accessory pigments
are organized in the thylakoid membranes to form reaction centers.
8. Light reactions occur in grana and dark reactions occur in stroma.

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STRUCTURE OF CHLOROPLAST

9. Chlorophyll is such a pigment which contains one atom of Magnesium.

10. Two major kinds of chlorophylls – chlorophyll a and chlorophyll b are

associated with thylakoid membranes. Around 250 to 400 pigment molecules
are grouped as light harvesting complex or photosynthetic unit in each
granum.

10. What is the role of acid in stomach?

Ans: The gastric glands of the stomach secrete gastric juice which contains hydrochloric
acid and enzymes.
Role of acid in the stomach
1. It kills the bacteria that enter through the ingested food.
2. It converts the inactive pepsinogen into active pepsin which digests proteins.

11. Mention the names of organs and glands which help in digestion.
Ans:
s.no. Name of the organ Name of the gland
1. Mouth (Buccal cavity) 1. Salivary glands
2. Pharynx 2. Gastric glands
3. Oesophagus 3. Liver
4. Stomach 4. Pancreas
5. Small intestine 5. Intestinal glands
6. Large intestine
7. Rectum and Anus

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12. How is the small intestine designed to absorb digested food? Explain.
Ans:
1. Transport of products of digestion from the small intestine into blood is called
absorption.
2. Intestine is a narrow-coiled tube of about 6.25 meters length.
3. Internally it consists of small finger like projections called microvilli.
4. Villi enhance the surface area of absorption.
5. Each villus is provided with network of blood vessels and lymph vessels.
6. Products of digestion are first absorbed into the villi and then into the blood
vessels and lymph vessels.
7. Presence of villi in intestine helps in maximum absorption of digested food.

13. How are fats digested in our bodies? Where this process does takes place?
Ans:
1. Small intestine is the site of the digestion of fats.
2. In the duodenum fats are converted to small globule-like forms with the help
of bile juice secreted by the liver. This process is called emulsification.
bile juice
Fats 
duodenum
Fat globules.
3. Lipase present in pancreatic juice and intestinal juice acts on emulsified fat
globules to convert them into fatty acids and glycerol.

lipase
Fat globules   fatty acids  glycerol

14. What is the role of saliva in the digestion of food?

Ans:
1. Saliva is a watery fluid secreted by salivary glands into the buccal cavity.
2. The food cut and crushed by our teeth in the buccal cavity mixes with saliva
and becomes wet and slippery.
3. Saliva contains an enzyme ptyalin which help in break down of complex
carbohydrates into simple sugars.

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15. What will happen to protein digestion as the medium of intestine is gradually
rendered alkaline?
Ans:
1. In the stomach, proteins are partially digested with the help of enzyme
pepsin.
2. When small intestine receives bile juice and pancreatic juice nature of the
food gradually changes from acidic to alkaline.
3. The small molecules of proteins are further broken down to amino acids
which are absorbed into the blood through villi of small intestine.

16. What is the role of roughage in the alimentary tract?

Ans: Roughage is the fibrous and indigestible substance that is obtained from vegetable
foods that do not provide any nutrients when consumed.
Role of roughage
1. Roughage cleans the alimentary canal and keeps it healthy.
2. It helps in the smooth passage of food through the alimentary canal.
3. Constipation can often be avoided by having plenty of roughage in the diet.

17. What is malnutrition? Explain some nutrition deficiency diseases.

Ans:
Eating of the food that does not have one or more than one nutrient in required
amount is called malnutrition.
Kwashiorkor: This is caused due to deficiency of proteins.
Symptoms:
1. Body parts become swollen due to accumulation of water in intercellular
spaces.
2. Very poor muscle development.
3. Swollen legs.
4. Fluffy face, difficult to eat, diarrhoea and dry skin.
5. Loss of appetite.

Marasmus: It is due to deficiency of both proteins and carbohydrates in the diet. It

generally occurs when there is immediate second pregnancy or repeated child
births.

Symptoms:
1. Child becomes lean and weak.
2. Less developed muscles.
3. Dry skin and diarrhoea.
4. Prominent ribs
5. Dry and wrinkled skin.

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Asking questions and making hypothesis

18. How do fungi and bacteria obtain their nourishment?

Ans:
1. Non-green plants such as fungi and bacteria cannot prepare their food.
2. They are saprophytes. They obtain their nutrients by the decomposition of
organic matter by releasing enzymes.
Eg: bread molds, yeast, mushroom, bacterium e.t.c.

19. If we keep on increasing CO2 concentration in air what will be the rate of
photosynthesis?
Ans:
1. The volume of CO2 in the air is 0.03%.
2. Increase in the concentration of CO2 in the
air increases the rate of photosynthesis up
to certain extent.
3. Beyond certain increase in the CO2
concentration some other factors like light
may act as limiting factor and there will not
be any increase in rate of photosynthesis
and it stays constant.

20. What happens to plant if the rate of respiration becomes more than the rate of
photosynthesis?
Ans: 1. During day time, the rate of photosynthesis is usually higher than that of
respiration while at night it is just reverse in most plants.

2. If the rate of respiration becomes more than the rate of photosynthesis, all
the synthesized carbohydrates are completely utilized during respiration and
there will be no food for the storage. The plant becomes weak and dies
gradually.

Experimentation and field investigation

21. Why do you think that carbohydrates are not digested in the stomach?
Ans:
1. Digestion of carbohydrates requires alkaline medium.
2. The enzymes( ptyalin and pancreatic amylase) which act on carbohydrates are
active in alkaline medium.
3. Where as in the stomach, due to the presence of HCl (hydrochloric acid) the
medium becomes acidic. So, the enzymes for digestion of carbohydrates
become inactive.
4. Hence, there is no possibility of digestion of carbohydrates in the stomach.

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22. What process do you follow in your laboratory to study presence of starch in
leaves?
Ans:
Aim : To study the presence of starch in leaves.
Apparatus : Beaker, test tube, tripod stand, Bunsen burner, asbestos gauze,
water, methylated spirit, leaf.
Procedure :
1. Detach the leaf from the plant.
2. Dip the leaf in boiling water for a minute. This process destroys the enzymes
in the leaf and suspends all the chemical changes taking place in it.
3. Boil the leaf in methylated spirit over a water bath. The leaf becomes
colourless due to the removal of chlorophyll. The leaf also becomes hard and
brittle.
4. Spread the leaf in a dish and add a few drops of tincture iodine solution on it.

Observation: The leaf turns blue–black colour indicating the presence of starch.
Result Confirmation: The experiment proves that starch is present in leaves

Precautions:
1. Be careful while using Bunsen burner.
2. Don’t boil test tube directly on the flame
3. Take the leaf carefully from the test tube by using a brush.

23. How do you demonstrate the green plants release oxygen when exposed to
light?
Ans: Aim: To prove that oxygen is evolved from green plants when exposed to light.
Apparatus: Beaker with water, test tube, funnel, hydrilla twigs, glowing incense
stick.
Procedure:
1. Arrange the apparatus as shown in figure. And make two identical sets with
water plant (like Hydrilla).
2. Place some water plant hydrilla in a beaker containing pond water, and cover
these by a short stemmed funnel.

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3. Invert a test - tube full of water over the stem of the funnel.
4. Ensure that the level of water in the beaker is above the level of the inverted
funnel.
5. Place the apparatus in the sun for at least 3 hours.
6. Arrange the second set in the same way, cover it with black paper / cloth keep it
under shade.

Observation: After sometime, in the first set it is observed that gas bubbles come
from the hydrilla plant. These bubbles are collected at the end of the test tube
pushing the water into the beaker.

After sufficient gas is collected test - tube is taken out of the beaker carefully by
closing it with thumb.

When a glowing incense stick or match stick is inserted in the test tube, it bursts
into flames.

Result Confirmation: This shows that oxygen is evolved during the process of
photosynthesis.

Precaution: Be careful while removing the test-tube from the beaker by

closing it with thumb.

24. What process did you follow to prove that carbon dioxide is necessary for
photosynthesis (Mohl’s half leaf experiment)?
Ans. Aim : To prove that carbondioxide is neccessary for photosynthesis or Mohl’s half
leaf experiment
Apparatus:
Wide mouthed transparent bottle, KOH solution, potted plant, vertically split cork.
Idoine solution.

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Mohl’s half leaf experiment

Procedure:
 Arrange the apparatus as shown in the figure.
 Take a potted plant and keep it in the dark for three days for the removal of starch
from the leaves.
 Take a wide mouthed transparent bottle.
 Put potassium Hydroxide (KOH) solution or KOH pellets in the bottle.

KOH absorbs carbon dioxide in the bottle.

 Insert splitted cork in the mouth of the bottle.
 Insert one of the leaves of destarched plant through a split cork into transparent
bottle containing KOH pellets or KOH solution.
 Leave the plant in sunlight.
 After a few hours, test this leaf and other leaf of this plant for starch with Iodine
solution.

Observation :
 The part of the leaf outside the bottle turns blue-black because starch is formed in
that part due to photosynthesis.
 The part of the leaf inside the bottle does not turn blue - black because the
carbondioxide is present inside the bottle is absorbed by potassium hydroxide
solution.

Precaution:
 The part of the leaf kept inside the bottle should not touch KOH.
 The apparatus should be kept air tight by applying grease or Vaseline

Result:
 This experiment proves that CO2 is necessary for photosynthesis.

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25. Write the procedure to prove that sunlight is necessary to form starch
in green plants?
Ans. Aim: To prove that sunlight is necessary to form starch in green plants.
Apparatus: Potted plant, light screen, iodine solution.

Procedure:
 Take a potted plant and destarch it by keeping in the dark for three days.
 Cover one of its leaves with black paper on which a design is cut.
 Fix the paper on the leaf in such a manner that light does not enter the dark part.
 Place this plant in the sun for few hours.
 After few hours of exposure to bright sunlight, test the leaf which is covered by
black paper for the presence of starch.
Observation:
 It will be observed that only the parts of the leaf, which could get light through the
cut design, turns blue - black showing the presence of starch.
Precautions:
 Cover the black paper carefully.
 Do not fold the leaf.
Result:
 This experiment proves that sun light is necessary for photosynthesis.

Information skills and Projects

26. Visit a primary health center and collect the information about children at
different ages suffering from malnutrition.
Ans:
s.no. Age group No. of children with malnutrition
1. 0-1 year Proteins Calories Vitamins
2. 1-3 year 1 2 1
3. 3-5 years 4 2 1
4. 5-7 years 3 1 3
5. 7-10 years 3 1 3

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Communication through drawing and model making

25. Would the survival of organisms become difficult if there are no green plants
on earth? Why? Why not?
Ans:
1. Plants are autotrophs that can synthesize food for themselves as well as for
animals and human beings.
2. By the process of photosynthesis, green plants produce food and oxygen.
3. The entire oxygen of the atmosphere is derived from photosynthesis. It is useful for
the process of respiration.
4. Plants not only produce food and give out oxygen, but they also give us shelter,
clothes, fuels and medicines.
5. Plants absorb carbondioxide thus save the earth by reducing its concentration.
6. If there were no plants there would be no life on the earth.

26. Draw the label diagram of human digestive system? List out the parts where
peristalasis takes place.

Peristalsis occurs in :
a. Oesophagus
b. Stomach
c. Small intestine
d. Large intestine

27. Raheem prepared a model showing the passage of the food through different
parts of the alimentary canal? Observe this and label its parts.

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28. Observe the following diagram and write a note on light dependent, light
independent reactions.

Ans: The given diagram shows the structure of chloroplast and the reactions taking place
in it.
1. Photosynthesis is the process by which green plants make their food from
carbon dioxide and water by using sunlight in the chlorophyll of green leaves.

light
2. 6CO2 + 12H2O 
chlorophyli
 C6H12O6 + H2O + O2

3. During photosynthesis several events occur in the chloroplasts of leaves.

They are
a. Conversion of light energy to chemical energy.
b. Photolysis of water (splitting of water molecule).
c. Reduction of carbondioxide to carbohydrate.

4. Light is required for several events of the photosynthesis (Light phase) while
other reactions continue in absence of light (dark phase).

Light phase (Light dependent )

It is also known as photochemical phase. The steps involved in this phase are:
Step–I: The chlorophyll on exposure to light energy becomes activated by
absorbing photons.
Chl  Chl* (activated chlorophyll)

Step – II: The energy is used to split water molecule to release oxygen.
This reaction is known as photolysis of water and as it was discovered by Robert
Hill, it is also called as Hill’s reaction.

Step – III: OH- ions through a series of reactions produce water and oxygen.
ATP and NADPH (assimilatory powers) are formed at the end of light reaction.

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Dark Phase (Light independent phase)

1. It is also known as biosynthetic phase.

2. It doesn’t depend on light i.e., it occurs in the presence and absence of light.

3. In this phase CO2 is reduced to carbohydrate (glucose) in a cyclic pathway.

4. These cyclic reactions are discovered by Melvin Calvin. So these reactions

are called Calvin cycle.

5. The ATP and NADPH formed in light reactions provides energy for the
synthesis of glucose from carbondioxide.

6. Finally the glucose is converted to starch.

Glucose, water and oxygen are the end products of photosynthesis.

Appreciation and aesthetic sense and values

29. What facts about green plants do you appreciate?

Ans:
1. The leaf is the important site of photosynthesis.
2. This plant organ is treated as a wonderful natural machine that uses solar
energy for the preparation of food.
3. Every organism directly or indirectly depends on plants for its food.
4. With all his scientific knowledge and technical skills, man has not produced
anything similar to leaf for utilization of solar energy in the preparation of
food.
5. This machine provides food and supports life by providing oxygen for all
organisms. Nature has given us such a wonderful machine free

Application to daily life and concern to biodiversity

30. What food habits you are going to follow after reading this chapter? Why?
Ans: After reading the chapter – Nutrition, I would like to follow the following food habits.
1. Having simple, well-balanced meals.
2. Eating them in a leisurely manner.
3. Thoroughly masticating the food.
4. Avoiding strenuous exercise soon after eating food.
5. Drinking plenty of water.
6. Intake of fiber rich food to avoid constipation.
7. Decreasing consumption of coffee or tea per day.
8. Taking leafy vegetables at least 2 or 3 times a week.
9. Maintaining regular timings for daily food consumption.

All these food habits will help in efficient functioning of digestive system.

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Choose the correct answer

1. Structure of chlorophyll is similar to [ ]

(A) Haemoglobin (B) sugar (C) fatty acid (D) amylase

2. Identify the correct statement about the Priestley’s experiment. [ ]

(A) By the introduction of mint plant mouse died in the bell jar and candle
extinguished.
(B) By the introduction of mint plant mouse alive in the bell jar and candle
exitinguished.
(C) There will be no relation between mint plant, mouse and candle.
(d) There will be an exchange of gases between the mint plant and mouse which
makes the candle glow and keeps the mouse alive.

3. Light reaction of photosynthesis results in formation of ______. [ ]

(A) O2 (B) NADPH + H+ (C) ATP (D) All of these

4. Which of the following are NOT essential for photosynthesis? [ ]

(A) CO2, optimum temperature (B) Glucose and oxygen
(C) Water and minerals (D) Light and chlorophyll

5. Given along side is a sketch of a leaf partially covered with black paper which is
Used in a photosynthetic experiment. Identify the part(s) of the leaf which will
become blue-black when dipped in iodine solution? [ ]

(A) I only (B) II only (C) I and III (D) II and III

6. Which part of the plant takes in carbon dioxide from the air for photosynthesis?
[ ]
(A) Xylem (B) Stomata (C) Leaf veins (D) Sepals

7. These are capable of converting light energy into chemical energy. [ ]

(A) Heterotrophs (B) Amoeba (C) Autotrophs (D) Bacteria

8. Which of the events listed below occur in the light reactions of photosynthesis?
(A) NADP is produced [ ]
(B) NADPH is reduced to NADP+
(C) carbon dioxide is incorporated into PGA
(D) light is absorbed and oxidizes chlorophyll

9. Equation of photosynthesis was first proposed by [ ]

(A) Arnon (B) C.B.Van Neil (C) Hill (D) Jackson

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10. The source of oxygen evolved during photosynthesis is [ ]

(A) H2O (B) CO2 (C) Chlorophyll-a (D) Glucose

11. Which of the following element is needed for biosynthesis of chlorophyll? [ ]

(A) Copper (B) Magnesium (C) Calcium (D) Chlorine

12. Oxygen was discovered by [ ]

(A) Priestly (B) Lavoisier (B) Arnon (D) Van Neil

13. In photosynthesis, the first step is [ ]

(A) Photolysis of water (B) Production of NADPH2
(C) Photoexcitation of chlorophyll (D) Synthesis of ATP

14. Light and dark phases of Photosynthesis take place in ______ and ______ of the
chloroplast respectively. [ ]
(A) Stroma and grana (B) Stroma and lamellae
(C) Thylakoid and quantosome (D) Grana and stroma
15. Who discovered the importantance of light in photosynthesis? [ ]
(A) Von Sachs (B) Arnon (C) Ingenhousz (D) Watson

16. Which of the following are products of the light reactions of photosynthesis that are
utilized in the Calvin cycle? [ ]
A) CO2 and glucose B) H2O and O2
C) ADP, Pi , and NADP+ D) ATP and NADPH

17. Pelletier and Caventou obtained an extract of the green coloured substance.
What was it? [ ]
(A) Chlorophyll (B) Nucleus (C) Mitochondria (D) Stomata

18. The name ‘chloroplast’ was coined by [ ]

(A) Arnon (B) Julius Von Sachs (C) Van Neil (D) None

19. Light reaction takes place in the following part of chloroplasts. [ ]

(A) Grana (B) Stroma (C) Matrix (D) Cristae

20. “Assimilatory power” is [ ]

(A) ATP (B) ADP (C) NADP (D) ATP and NADPH

21. Dark reaction takes place after light reaction [ ]

(A) After 1 hour (B) After 10 hours (C) After 24 hours (D) Simultaneously

22. Reduction of carbon dioxide takes place in [ ]

(A) Dark reaction (B) Light reaction (C) Glycolysis (D) Respiration

23. Enzyme which does not act on proteins/peptides is [ ]

(A) Trypsin (B) Pepsin (C) Peptidases (D) Amylase

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24. Food vacuoles are seen in [ ]

(A) Fungi (B) Amoeba (C) Cuscuta (D) Leech

25. Dodder plant draws water and minerals from host plant through [ ]
(A) Roots (B) Haustoria (C) Rhizome (D) Mycorrhizae

26. The enzyme present in pancreatic juice converts emulsified fats into glycerol and
fatty acids is _____ [ ]
(A) Amylase (B) Rennin (C) Lipase (D) Pepsin

27. Elimination of undigested food through anus is called [ ]

(A) digestion (B) absorption (C)excretion (D) defecation

28. Ptyalin enzyme is present in [ ]

(A) Bile juice (B) Gastric juice (C) Saliva (D) Intestinal juice

29. Intake of fiber rich food avoids [ ]

(A) Digestion (B) Absorption (C) Constipation (D) Assimilation

30. Enzyme trypsin is secreted by [ ]

(A) Pancreas (B) Liver (C) Kidney (D) Lungs

31. Pancreatic amylase converts carbohydrates into [ ]

(A) Sucrose (B) Maltose (C) Galactose (D) Glucose

32. This is a fat soluble vitamin. [ ]

(A) A (B) D (C) E (D) All of these

33. Vitamin K is synthesized by bacteria in _________ [ ]

(A) Mouth (B) Duodenum (C) Small Intestine (D) Large intestine

34. This is a protein deficiency disease. [ ]

(A) Marasmus (B) Kwashiorkar (C) Obesity (D) Rickets

35. This occurs due to the deficiency of both proteins and calories. [ ]
(A) Marasmus (B) Scurvey (C) Kwashiorkar (D) Night blindness

36. Ascorbic acid is the chemical name of [ ]

(A) Vitamin-A (B) Vitamin-C (C) Vitamin-D (D) Vitamin-K

37. This vitamin is available in morning sun rays. [ ]

(A) Vitamin-A (B) Vitamin – D (C) Vitamin – K (D) Vitamin – C

38. Fertility disorders are due to the deficiency of [ ]

(A) Vitamin-E (B) Vitamin-K (C) Vitamin-D (D) Vitamin-A

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39. Blood clotting is delayed due to the deficiency of [ ]

(A) Vitamin-E (B) Vitamin-K (C) Vitamin-D (D) Vitamin-A

40. Consumption of excess fat results in: [ ]

(A) Kwashlorkar (B) Marasmus (C) Obesity (D) vitaminosis

41. ‘Beri Beri’ is due to the deficiency of [ ]

(A) B1 (B) B2 (C) B3 (D) B6

42. Deficiency of Niacin causes this disease. [ ]

(A) Rickets (B) Pellagra (C) Glossitis (D) Burning feet

43. Water soluble vitamin is: [ ]

(A) Vitamin-B12 (B) Vitamin-K (C) Vitamin-D (D) Vitamin-A

44. Pernicious anaemia is due to the deficiency of [ ]

(A) Cyanocobalamine (B) Riboflavin (C) Thiamine (D) Biotin

45. Weak bones, delayed dentition, knocknees, swollen wrists are the symptoms of the
following disease. [ ]
(A) Scurvy (B) Rickets (C) Pellagra (D) Glossitis

46. Consider the following statements:

(i)Chlorophyll ‘a’ is yellow-green in colour and chlorophyll ‘b’ is blue-green in colour
(ii)Oesophagus doesnot possess digestive glands but action of salivary amylase on
Starch continues in it.
Which of these statement(s) is/are correct? [ ]
(A) Only(i) (B) Only(ii) (C) Both (i) and (ii) (D) Neither(i) nor(ii)

47. The chemical name of vitamin ‘E’ is [ ]

(A) Tocoferol (B) Phylloquinone (C) Calciferol (D) Retinol

48. Night blindness, Xerophthalmia are due to the deficiency of [ ]

(A) Vitamin-A (B) Vitamin-K (C) vitamin-D (D) Vitamin-E

49. The passage of digested food through the walls of small intestine into circulatory
System is called [ ]
(A) ingestion (B) digestion (C) absorption (D)assimilation

50. This vitamin is abundantly available in citrus fruits and sprouts. [ ]

(A) Vitamin-K (B) Vitamin-C (C) Vitamin-D (D) Vitamin-E

51. Scurvy is due to the deficiency of this vitamin. [ ]

(A) B12 (B) C (C) D (D) K

52. The emulsification of fats is carried out by [ ]

(A) lipase (B) bile (C) pepsin (D) HCl

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53. Dodder belongs to the family [ ]

(A) Fabaceae (B) Leguminaceae (C)Solanaceae (D) Convolvulaceae

54. Carbohydrate digestion does not occur in: [ ]

(A) Stomach (B) Buccal cavity (C) Small intestine (D) All of these

55. The main reason for boiling green leaf in methylated spirit is [ ]
(A) To make the leaf thin and soft
(B) To remove the chlorophyll present in the leaf
(C) To make the leaf thick and hard
(D) To kill the tissues present in the leaf

KEY
1 A 2 D 3 D 4 B 5 C
6 B 7 C 8 D 9 B 10 A
11 B 12 A 13 C 14 D 15 C
16 D 17 A 18 B 19 A 20 D
21 D 22 A 23 D 24 B 25 B
26 C 27 D 28 C 29 C 30 A
31 B 32 D 33 D 34 B 35 A
36 B 37 B 38 A 39 B 40 C
41 A 42 B 43 A 44 A 45 B
46 B 47 A 48 A 49 C 50 B
51 B 52 B 53 D 54 A 55 B

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NUTRITION - FOOD SUPPLYING SYSTEM

ADDITIONAL QUESTIONS

I. Conceptual Understanding
1. What are the end–products of the digestion of starch, proteins and fats?

2. Why is small intestine the most important organ of the digestive system?

3. Define the following terms:

(i) Peristalsis (ii) Malnutrition (iii) Emulsification (iv) Enzyme

4. Describe different types of heterotrophic nutrition

.
5. What is bilious or liverish? What is the reason for this condition?

6. Amoeba is a heterotrophic. What does this statement mean?

II. Asking Questions and Making hypothesis

1. What questions do you ask to know about scientists related to
photosynthesis?

2. Life owes its existence to chlorophyll. Give reasons

3. Only animals have a specific digestive system. Give reason

4. Why water is necessary for our body? Give any four reasons.

5. Given below a set of terms. Rewrite the terms in the correct order so as to be in
logical sequence as per the directions given in brackets:
(i) Water molecules, oxygen, grana, hydrogen and hydroxyl ions, photons.
(photosynthesis).
(ii) Destarched plant, iodine added, washed in water, a leaf boiled in alcohol,
placed in water, a leaf boiled in alcohol, placed in sunlight. (testing for
presence of starch).

III. Experimentation and field investigation

1. A candidate studied the importance of certain factors of photosynthesis. He took a
potted plant and kept it in the dark for over 24 hours. In the early hours of the next
morning, he covered one of the leaves with dark paper in the centre only. Then he
placed the plant in sunlight for a few hours and tested the leaf which was covered
with black paper.
(a) What aspect of photosynthesis was being investigated?
(b) Is there any control in this experiment? If so, state it.
(c) Why was the plant kept in the dark before the experiment?
(d) Describe step by step, how the candidate proceeded to test the leaf for the
presence of starch.

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2. Observe the given diagram of an experimental set–up and answer the following
questions.

(a) What is the purpose of this experiment?

(b) Will it work satisfactorily? Give reason.
(c) What alternation(s) will you make in it for obtaining expected result?
(d) Would you take any step before starting the experiment? Describe this step and
explain its necessity.

3. If you perform the hydrilla experiment by wrapping a black paper around the set up
completely what would be the result?

4. How does the purpose of de-starching a leaf help you to prove about the
importance of factors related to photosynthesis?

IV. Information Skills and Projects

1. Fill the following table

Name of
Deficiency
Sno the Resources Symptoms
diseases
vitamin
1. Niacin
2. Scurvy
3. Calciferol
Carrot, papaya, cod
4.
liver oil, mango, milk
Delay in blood clotting,
5.
over bleeding
6. Glossitis

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2. Complete the following by filling in the blanks numbered 1 to 10 with the appropriate
word/term:
Photosynthesis involves light reaction and dark reactions. During light reaction, the
chlorophyll present in the (1) _________ gets activated by absorbing light energy.
This energy splits (2) _________ molecules into (3) _________ and oxygen and
releases electrons. This process is called (4) _________. The (5) _________ ions
are picked up by NADP to form (6) _________. During this process ADP is
converted to (7) _________. This process is called (8) _________. During the
dark phase, the compound produced at the end of light reaction reacts with carbon
dioxide to form (9) _________. This product is converted to starch. The process is
called (10) _________.

3. Fill the following table.

Name of the
S.No Type of nutrition Process of obtaining food
organisms
1. Yeast Through cell membrane
2. Autotrophic nutrition
3. Tapeworm
4. Man
5. Swallowing

4. Write a flow chart on sequence of digestion of carbohydrates, proteins and fats in

different parts of human digestive system.

5. Collect information on gastroenterology and how it helps in detecting digestive

system disorders.

V. Communication through drawing, model making

1. Draw a neat labeled diagram of a transverse section of leaf.

2. Observe the figure given below and answer the

following questions:
(i) What does the figure represent?
(ii) Label the parts 1 – 3.
(iii) Mention its role.

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3. Observe the figure given and answer the

following questions:
(i) What does this figure show?
(ii) Label the parts marked 1–12.
(iii) Mention the functions of parts 1,
3, 4, 6, 8 and 10.

4. Given below is a schematic diagram to illustrate some aspects of photosynthesis.

(a) Fill up gaps, in blank spaces (1–4), by writing the name of the correct items.
(b) What phenomenon do you think arrows A and B indicate respectively?

VII. Application to daily life, concern to biodiversity

1. Why there are no enzymes to digest vitamins?

2. How thorough chewing of food helps you in digestion?

3. Prepare a possible menu for your dinner which would provide all the necessary
nutrients.

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4. Neelima is studying in class IV .She fell sick last week and visited a doctor with her
parents .He observed the symptoms and informed that Neelima is suffering from
Kwashiorkor. What symptoms of Kwashiorkor did the doctor observe?

5. Sudheer observed a parasitic plant with twines in his surroundings. He was

surprised to see a leafless plant with special structures. Read the following
questions and answer them.
a) What plant did Sudheer identify? Which genus does it belong to?
b) Why it is parasite?
c) What are those special structures called? How do they help the plant?
d) What are the leaves of parasitic plant reduced to?

QUESTIONS FROM PREVIOUS PAPERS

One mark questions

1. Mention the sources of Retinol.
2. Mention any two facts about nutrition in Amoeba ,that you appreciate.
3. What are heterotrophs? How do they obtain their food?
4. Write the equation that represents photosynthesis.
5. Draw the flow chart showing the process of nutrition.
6. How many types of vitamins are there? What are they?

Two marks questions

1. If haustoria do not develop in cuscuta , what do you think would happen?

2. You are aware of health aspects of alimentary canal . Write the related good
practices that you follow.

3. What disasters occur on earth, if photosynthesis stops?

4. Mention the symptoms which are common to kwashiorkor and marasmus.

5. Identify the following diagram and write the function of it.

6. What kind of food do you include in your diet in order to maintain good eye sight?
Why?

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Four marks questions

1. Describe the photo chemical phase of photosynthesis.

2. Name the parts present in the human alimentary canal.Mention the organs where
carbohydrates , proteins and fats are digested. What is the role of roughage in
digestion?

3. In the experiment to prove that ‘light is essential for photo synthesis”, what changes
did you observe in the leaf – tested with iodine? What precautions did you take
before and during conducting this experiment?

4. What procedure do you follow to test the presence of starch in leaves?

5. Read the table given below and answer the following questions.

6. Write about the enzymes that are released by the digestive system, the substances
they act upon and the end products formed.

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i). If salivary glands does produce saliva, what happens?

ii). Name the gland that produces enzymes that can digest carbohydrates, proteins and
fats.
iii). What is meant by Emulsification?
iv). Mention the substances on which the pancreatic juice acts?

7. Observe the given diagram and answer the questions.

i) What can we prove with this experiment.

ii) What are the apparatus and materials used in this experiment?
iii) What would be the result of this experiment if it is conducted in shade?
iv) What do you do to test the result of this experiment?

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8. Observe the given experiment set up and write your observations and conclusions.

i) What differences do you find between the experimental set up II and III? Why?
ii) What is common in set up II and IV?
iii) What is the role of mint plant in set up IV?
iv) What did you conclude from this experiment?

***

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