Shubharambha Science & Env 6 -2077 press re

6. Match the following:

Sugar distillation

Filtrate Coca cola

Sediments Filtration

Distillate Sedimentation

Carbon dioxide Solute

7. Encircle the pure substance from the following:

Salt, Water, Flour, Soil, Coca Cola, Iron
8. Which method is used to separate the following mixtures?

a. Mixture of salt and water b. Mixture of sand and iron filings

c. Mixture of water and kerosene d. muddy water

9. Draw a neat and labelled diagram of the process of sedimentation
and decantation.

10. Draw a neat and labelled diagram to show of filtration process.

11. What is evaporation? Describe the process of evaporation with the
help of a well labelled diagram.

Glossary : A tool for separating larger solid particles from smaller
solid particles.
Sieve
: combination of two or more substances.
Mixture : process of allowing insoluble solid to materials to settle
Sedimentation
down in a mixture.
Decantation : process of transferring the clear liquid without

Filtration disturbing sediments.
: process of separating an insoluble solid from a liquid by
Distillation
filter paper.
Winnowing : process of changing a liquid to vapour and cooling the
Sieving
vapour to get back the liquid.
: process of separating mixture with the help of wind.
: a process of separation of mixture by the help of wind.

Blooming Science & Environment Book 6 101

11Chapter Air

Learning Outcomes Estimated Periods: 4+2

On the completion of this unit, students will be able to:

 introduce air as a mixture and explain know properties of air.
 tell some physical and chemical properties of air
 explain role of different gases present in air.

Introduction

Air is found everywhere. Air is essential for all the living organisms to survive.
During respiration, a living organism breathes in oxygen present in air, and exhales
the carbon dioxide. All green plants use carbon dioxide present in air while preparing
food in the process of photosynthesis.

Composition of Air

Air is a mixture of many gases. Nitrogen gas is the most abundant of all the gases in

the air. The composition of air is generally the same everywhere, but the percentage

of water vapour and carbon dioxide may vary from place to place. The approximate

composition of the air, by volume, is as follows:

Gases Volume (%) others (1%) oxygen
(20.90%)

Nitrogen 78.1

Oxygen 20.9

Carbon dioxide 0.03 nitrogen
Inert gases 0.95 (78.10%)
Other gases 0.02

Water vapour and impurities are present in small amounts. The oxygen present in
the air makes respiration and combustion (burning) possible. Oxygen is a reactive
gas. Besides nitrogen, oxygen, carbon dioxide and water vapour, air also contains
helium, neon, argon and krypton in small quantities. These gases are called inert
gases. Nitrogen gas is taken in by plants to produce proteins. If the air around us
contained mostly oxygen, then even small fires would turn into huge explosions and
cause great damage. Some activities to prove components of wir are described below

102 Blooming Science & Environment Book 6

1. Oxygen is present in air.

Activity 1

Oxygen is present in the air.
Materials required: A bell-jar, phosphorus, a crucible, water and a trough
Methods:
1. Place a small quantity of Phosphorus in the crucible.
2. Keep the crucible on the surface of the water in the trough.
3. Cover the crucible with the bell jar
4. Mark the initial level of water in the bell-jar.
5. Burn the phosphorus and close the bell-jar mouth with a cork.
6. The oxygen present inside the bell jar is used by the burning Phosphorus. This

decrease the volume of the air in the bell jar.
7. As the jar begins to cool, the water level slowly rises in the bell-jar.
8. The water level eventually occupies 1/5 of the space in the bell-jar, compared with

the starting measure.
This proves that oxygen is present in the air and consists of about 20% of the air.

Gas jar

Phosphorus

Trough

Water

Activity 2

Oxygen is needed for burning.

Materials required: A gas jar, water trough, some water and burning candle.

Method:

i) light a candle and keep it at the middle of water trough.

ii) Slowly fill some water in it without disturbing burning candle.

iii) Gently cover the burning candle with gas jar and observe.

Observation:

The candle extinguished soon and the water level rise up in the gas jar.

Conclusion: crucible or small
cork plate
bell jar

candle

trough
water

Blooming Science & Environment Book 6 103

2. Water vapour is present in air

Activity 3

Water vapour is present in the air.
Materials required: A glass, some ice and some water.
Method:
1. Pour a little water into the glass and then put some pieces of ice

into it.
2. Leave the glass undisturbed for few minutes.
Observation:
You can see water droplets on the outer surface of the glass.
Conclusion:
1. The outer surface of the glass is cold, which causes condensation of the water

vapour that is present in the air.
2. This forms droplets of water on the outer surface of the glass.

This proves that water vapour is present in the air.

3. Carbondioxide is present in air

Activity 4

To prove that carbondioxide is present in the air Beaker

Materials required: a beaker, lime water Lime
Method: water

1. Take some lime water in a beaker or in a cup.

2. Leave the beaker or cup open for 2 to 3 hours.

Observation:

After 3 hours, it will found that the colourless solution turned into milky.

Conclusion:

It proves that air contains carbondioxide which converts the colourless lime water
into milky.

Properties of Air
 Air has weight and occupies space.
 When the air is pure, it is odourless, tasteless and colourless.
 Air moves from one place to another.
 Air, on heating, expands.

104 Blooming Science & Environment Book 6

 Air can be compressed.

 Oxygen present in air causes rusting of some metals.

 Oxygen is needed for burning the things

Rusting

The reddish brown layer on the surface of iron, when it is exposed to moist air for a

long time, is known as rust. The process of the formation of rust, caused by oxygen

and water vapour is known as rusting. Scan for practical experiment

Activity

Moist air causes iron to rust.

Materials required: Steel wool, a test tube, water, visit: csp.codes/c6e16
a beaker and a stand.

Method:

Place wet the steel wool in the test tube. The steel wool should stick at the bottom
of the test tube.

Now, invert the test tube in the beaker, which contains water.

Mark the level of water in a test tube with the help of a marker.

Leave the apparatus undisturbed for 2-3 days.

What will you observe?

What happens?

You will see that the steel wool becomes rusted and the water level in the test tube
rises.

This shows that moist air is responsible for rusting of iron.

rusted steel wool

steel wool

test tube stand
steel wool water

stand

Blooming Science & Environment Book 6 105

Air has weight

Activity

Air has weight.
Materials required: Two identical footballs
and a pan balance
Method:
Weigh both empty footballs, to confirm they
are of the same weight.
Fill one football with air and leave the other
football empty (without air).
Weight the two footballs again.
What differences will you see in their
weights?
What happens?
The ball filled with air shows a greater
weight, because of the air it contains.
The other football does not show any weight.

Uses of Air
 Air helps things to burn. The oxygen present in the air is responsible for

burning.
 All living organisms need oxygen during the respiration process.
 All green plants utilize carbon dioxide gas from the air to prepare food during

the process of photosynthesis.
 All living organisms utilize nitrogen from the air, directly, indirectly, while

preparing cells in their body.
 Air is used to fill balls, vehicle tyres, etc.

Uses of various Component of Air

Nitrogen
 Nitrogen helps in the growth and development of plant.
 Animals use nitrogen in manufacturing protein or indirectly.
 It is filled inside the electric bulb.
 It is used to manufacture various chemical fertilizers like urea, ammonium
sulphate etc.

106 Blooming Science & Environment Book 6

Oxygen
 Oxygen is used by all living organisms for respiration. It is also called as ‘ life
gas’.
 It is essential for burning the things.
 It is given to the patients in hospitals having respiratory problem.
 It is carried by mountainers, sea-divers and people working in deep mines for
breathing.

Carbon dioxide
 Carbon dioxide is used by all green plants to manufacture food in the process of
photosynthesis.
 It is used to extinguish fire.
 It is also used in aerated drinks like soda-water, coke, beer, etc.

Water vapour
 It helps to protect the leaves of plants from drying.
 It makes the fruits and vegetables fresh.
 It prevents from drying up of animal's skin.
 It is helpful in dew formation.

Main Points to Remember

1. Air is very important and life is impossible without air.
2. The main components of air are nitrogen, oxygen, carbon dioxide and water

vapour.
3. Air is needed for burning.
4. Air contains one-fifth volume of oxygen and 78.1% of nitrogen.
5. A brown layer formed on the surface of iron in the presence of moist air, is

called rust.
6. Iron gets rusted in the presence of oxygen and water.
7. Rusting can be prevented by protecting the metal by coatings.
8. The presence of carbon dioxide in air can be shown by blowing air through

lime-water when it will turn milky.
9. The presence of water in air can be demonstrated by keeping a glass full of ice

when droplets of water will appear on the outer surface of the glass.
10. Air is very useful in many ways.

PRO J ECTWORK

Make a table to show the composition of air and show in a diagram in the form of chart
in chart chart paper.

Blooming Science & Environment Book 6 107

Exercises

1. Choose a word to fill the blanks in each of the following sentences.

(78.1, proteins, respiration, weight, burning, moist, neon, carbon dioxide,
occupies, oxygen, 20.9, rusting)

a. All green plants use ...................... gas when preparing food.

b. Helium, argon and ...................... are inert gases.

c. Nitrogen occupies ...................... percent by volume in air.

d. Oxygen occupies ...................... percent by volume in air.

e. During respiration, all human beings exhale ......................gas and inhale
...................... gas.

f. Nitrogen from the air is taken by some plants to produce .....................

g. Oxygen is used for the .................... and .................... processes.

h. ...................... air is responsible for ...................... of iron.

i. Air has ...................... and ......................space.

2. Are the following statements True (T) or False (F).

a. Very little oxygen and nitrogen are found in air.
b. Oxygen is the main cause of the formation of rust in iron.

c. Impure air is odourless.

d. Plants take in oxygen gas during respiration.

e. Air contains water vapour.

3. Match the following. 20.9
0.03
Nitrogen 0.095
Oxygen 78.1
Carbon dioxide 0.02
Inert gas
Other gases

4. Answer these questions

a. Name the gas present in large percent by volume in the atmosphere.
b. Name the atmospheric gas which is a supporter of combustion.

d. Write any four properties of air.

108 Blooming Science & Environment Book 6

e. Write any three uses of air.
f. How is rusting possible on iron?
g. How can you prove that air contains water vapour?
h. How do plants help in maintaining the percentage of gases in the air?
i. Write the composition of air.
j. What would happen if plants did not use carbon dioxide from the air?
k. What is the function of nitrogen?
l. What would happen if the air around us consists mostly of oxygen?
m. How can you prove that air has weight? Describe with a diagram.
n. Moist air causes the rusting of iron. Explain with a diagram.
o. Describe with diagrams that oxygen is present in the air.
p. Describe an experiment to show carbondioxide is present in air.

Glossary

rusting : a slow process of oxidation of iron with air

respiration : the process of release of energy from food

mist : fog

lime water : a solution of calcium hydroxide in water

Blooming Science & Environment Book 6 109

12Chapter Metals and Non-Metals

Learning Outcome

On the completion of this unit, students will be able to: Estimated Periods: 3

 introduce metals and non-metals and their properties.
 differentiate metals and non-metals.
 tell the uses of metals and non-metals in daily life.
 give general introduction of some metals (Iron, Copper, Silver and Gold)

used in daily life.

Elements that are mostly hard, shiny and good conductors of heat and electricity are
known as metals. The earth consists of many chemical materials. Minerals are found
mixed with sand and clay etc. There are about 118 known elements. More than three
fourth of them are metals. A typical metal is hard and shiny, tough and strong and is a
good conductor of electricity and heat. Metals have many uses in our daily life. Often
they are mixed or combined with other metals or substances to form alloys.

Spoon Can Gold Car

The materials generally contain various elements and compounds and are known as
minerals.

Almost any machine or device has at least one metal in it. The most widely used
metal is iron, but not in its pure form. It is combined with small amounts of the non-
metal carbon, to form the group of alloys known as steel. Making alloys is extremely
important in industry. Alloys of a metal are often harder and stronger than the pure
metal itself. The science of metals is called metallurgy. Gold, silver, iron, platinum
and copper are some examples of metals. Metals occur in a combined state in nature,
in the form of their compounds, like oxides, sulphides, sulphates, nitrates, chlorides,
etc. and these compounds are called ores.

Properties of Metals

 They are generally solids, except mercury and gallium, which are liquids.

 Molecules are very closely packed together with strong intermolecular force and
they are hard.

110 Blooming Science & Environment Book 6

 Metallic minerals shine.
 Many of them can be beaten into sheets. This property is known as malleability

and substances that show this property are called malleable substances.
 Some metals can be drawn out to form wires. This property is called ductility

and such metals are said to be ductile.
 Most metals are good conductors of heat and electricity.
 They produce a clear sound when they are struck.
 They show shining property called luster.

Activity 1

To prove that metals can produce sound and non-metals cannot.
Material required: An iron sheet, a wooden sheet, a rod and a stick.
Method:
Take the iron sheet and use the rod to hit the iron sheet.
Similarly, hit the wooden board with the stick.
What will happen?
The iron sheet is metal, which produces a big and sharp sound when it is struck with
a rod. When a wooden sheet is struck, it produces a dull sound that is less loud.

Activity 2

To prove all metals are good conductors of heat.
Material required: A burning candle, an iron
rod, a wooden stick
Method:
Take the iron rod and the wooden stick.
Heat the ends of the iron rod and the wooden
stick.
Which one feels hot where you are holding it?
Why can you not hold the iron rod for a long
time?
What will happen?
The iron rod becomes hot very fast and it is difficult to hold it after heating. This
does not happen with the wooden stick. Heat is transferred in the iron rod because
it is a metal, but heat transfers very slowly in wood. The wooden stick is a
non-mental.

Blooming Science & Environment Book 6 111

Uses of Metals
 Metals are used to make electric wires and utensils.
 Alloys, such as brass, bronze, etc, are made from metals.
 Jewelery and medals are made from gold, silver and copper.
 Vehicles like trains, aircraft, buses, cars and motorbikes are all made of metals.
 Weapons, knives, chairs, tables, windows and agricultural appliances are also

made of metal.
 It is also used in making coins.
Iron
Iron is a very popular metal from ancient time.
Its symbol is Fe derived from its Latin name
ferrum. It is 26th element of periodic table.
It is a silvery white and lustrous metal. It melts
at 1500oC and boils at 2500oC. It is heavier
than aluminum but lighter than silver and gold. It slowly reacts with air to make
brown layer over it which is popularly known as rusting of iron. Iron is used to make
weapons and for making construction materials like rods, bolts, pipes, way track,
vehicles etc.

Copper
The Latin name of copper is cuprum and its symbol is Cu.
It is 29th element of the periodic table. Copper is widely
used to make coin, so it is also called coinage metal. Its
m.p is 1000oC and b.p is 2350oC. It is heavier than iron.
Copper is widely used for making electrical goods and
cables because it is good conductor of electricity. It is used
in electroplating, to make dyes and pesticides.

Silver
Silver is also known as coinage metal. Its Latin name
is Argentum and its symbol is Ag. It is in 47th positions
in the periodic table. Its valency is 1. It is a white
lustrous metal. Its m.p is 960oC and b.p is 1955oC. It
is a good conductor of heat and electricity. Silver is
used in making coins, jewellery and to make curative articles. It is used in silvering
of mirror and to fill teeth.

112 Blooming Science & Environment Book 6

Gold

Gold is also known as coinage metal and very
expensive metal commonly called ‘Pahelo
dhatu’. Its Latin name is Aurum and its symbol
is Au. It is in 79th position in the periodic table. It is a soft lustrous yellow metal. Its
m.p is 1069oC and b.p is 2610oC. It is heavier than Cu, Fe and Ag. It is a best good
conductor of heat and electricity. It is widely used for making jewellery, coins and
metals. There is high demand of gold jewelleries in our society during marriage.

Non-Metals

Non-metals are soft elements that are dull in appearance. Carbon, nitrogen, oxygen
are some examples of non-metals. Non-metallic minerals are rock salt, quartz,
limestone, mica chalk.

Properties of Non-Metals Scan for practical experiment

1. They may be found in solid, liquid or gaseous states.

2. They are softer than metals.

3. They do not shine or reflect light and do not have a
metallic lustre.

4. They do not conduct heat and electricity.(except graphite) visit: csp.codes/c6e17

5. They cannot be beaten into sheets ie. they are non-
malleable.

6. Non-metals are not ductile, so wire cannot be made from them.

7. They do not produce a bell like sound when they are struck.

Uses of non-metals
1. Non-metals are used as insulators in electric wires and electrical appliances.
2. These are used to fill up the balloons.
3. Some non-metals like hydrogen and oxygen are used as fuels in rockets.
4. Non-metalslike Sulphur is used to make explosive materials.
5. A form of carbon (diamond) is used in jewellery and a form of carbon (graphite) is
used in pencil to write.

Alloys

Mixtures of metals that are prepared by melting and mixing different metals together,
in definite proportion by weight, are known as alloys.

Properties of Alloys

1. They are hard, malleable and ductile.

2. They show resistance to corrosion (chemical attack by atmosphere, water and
soil)

3. Alloys are good conductors of electricity and heat.

Blooming Science & Environment Book 6 113

Name of alloys Composition Properties Uses

Steel Iron, nickel, Resists corrosion Cutlery and machine parts
Magnalium chromium
Light, tough and Scientific instruments,
Aluminium, resists corrosion aircraft
Magnesium

Bronze Copper, tin Hard Statues, coins, medals

Brass Copper, zinc Can be easily moulded, Cartridge cases, musical

resists corrosion instruments, machine parts

Metalloids

There are some elements like arsenic, antimony and germanium that show the
properties of both metals and non-metals. Such elements are called metalloids.
Thus, elements that show the properties of both metals and non-metals are called
metalloids. Metalloids possess the following characteristics:

1. They are poor conductors of heat and electricity.

2. They possess metallic lustre.

3. They form alloys.

4. They are neither malleable nor ductile.

Differences between Metals and Non-metals

Metals Non-metal

1. Metals are found in solid state. 1. Non-metals are found in solid, liquid or
2. Metals are hard. gas states.

2. Non-metals are soft.

3. Metals produce sharp sound. 3. Non-metals do not produce sharp sound.

4. Metals have lustre. 4. Non-metals have no lustre.

5. Metals can be drawn into thin wire. 5. Non-metals cannot be drawn into thin

(Ductile) wire.(Non-ductile)

6. Metals can be made thin by 6. Non-metals cannot be made thin by

hammering. (Malleable) hammering.(Non-malleable)

7. Metals are good conductors of heat 7. Non-metals are bad conductors of heat

and electricity. and electricity.

Main Points to Remember

1. Matter occupies space and has mass and exist in three states.
2. An element is a substance that cannot be split up into two or more simpler

substances.

114 Blooming Science & Environment Book 6

3. All the elements can be grouped into metals, non-metals and metalloids.
4. Metals are shiny, generally heavy and good conductors of heat and electricity.
5. Non-metals are not shiny and are usually found in soft solid or liquid or

gaseous states. They do not conduct electricity.
6. Elements that show the properties of both metals and non-metals are called

metalloids.
7. Two or more metals or non-metals are mixed together in liquid state to form

alloy.
8. Brass, steel and stainless steel are some examples of alloy.
9. Copper, silver and gold are called coinage metals.
10. The science of metals is called metallurgy.

PRO J ECTWORK

1. Collect some substances in your surroundings. Identify what are metals and
what are non metals.

2. Visit your kitchen and make a list of items that are made of metals and alloys.

Exercises

1. Fill in the blanks.

a. Wood is …………………. conductor of heat.
b. Plastics are ……………….. conductor of electricity.
c. ……………………….. is a good conductor of heat.
d. …………………… produces tinkling sound.
e. ……………………… are not ductile.
2. Correct the following statements.
a. Most of the non-metals are soft.
b. Non-metals possess luster.
c. Non-metals are the good conductor of electricity.
d. Diamond is the hardest metal known.
e. Gold is lighter than iron.
3. Answer the following questions.
a. Write down the names of five substances that are lustrous in our daily life.
b. Write down the names of metals and non-metals that are used in building

construction.

Blooming Science & Environment Book 6 115

c. Write down three names of metals that are used in making coins.
d. Write four methods by which we can identify metals and non-metals.
e. How can you prove that iron is good conductor of heat?
f. How can a blind man identify the given plate is made of iron or plastic?
g. Distinguish between metals and non-metals.
h. Define alloys with examples.
i. When a touch, iron is cooler than wood. Why?
j. What are the properties of non-metals?
k. Define metalloids with examples.
4. Arrange the following in the order of hardness.

Iron, soil, aluminium, silver, ice, brick
5. Write uses of gold and silver.

6. Write boiling point and melting point of iron, silver, copper and gold.

Glossary

coinage : money
metallurgy : study of metals
malleability : able to be shaped and bent
ductility : readily shaped
alloys : mixture of two more metals
metalloid : properties lies in between metals and non-metals
corrosion : decay or rust
lusture : shining

116 Blooming Science & Environment Book 6

13Chapter Some Useful Chemicals

Learning Outcome Estimated Periods: 5
On the completion of this unit, students will be able to:

 tell about use of some chemicals used in daily life.
 describe the sources and uses of some chemicals like ediple salt, soda

turmeric, chook and yeast.

We use many different things made up of various chemicals in our daily life. We
use different chemicals from morning to evening for various life activities. Some
chemical substances we use for cleaning purpose and some others in our kitchen
also. We will be studying about some useful chemicals in this chapter.

The chemicals discussed here in this chapter are; Edible salt, Edible soda, Turmeric,
Acetic acid( chook amilo), Yeast, Ghee and Sugar.

a. Common salt

Common salt, which is widely used in our daily life is also called Table salt or Edible
salt. The chemical name of common salt is Sodium chloride(NaCl). It is obtained by
evaporating sea water or brine from brine wells. Mining a rock salt is also a major
source.

It is soluble in water and salty in taste. So, it is the most useful substance in our
kitchen. it is used in preparing various types of vegetable curry, fish,meat, pickles,
etc. It makes the food tasty as well as it is used as the preservatives for fish, meat,
pickles, etc. for their future use.

Common salt is also used as the source of iodine. Iodine is needed in small quantity
for our body. It helps to make a child active and prevents from goiter so, iodine is
mixed in common salt. The salt mixed with iodine is called iodized salt.

A packet of salt Salt in vessel Sea water evaporation

b. Baking Powder (Baking soda)
Baking powder commonly called as Edible soda or ‘ Khane soda’ is a chemical
mainly used in bakeries. Its chemical name is sodium bicarbonate (NaHCO3).The
baking powder is used in making bread, cake and biscuits as it makes these soft and

Blooming Science & Environment Book 6 117

large. It is also used in making 'selroti' and 'doughnet'. Edible soda is also used by the
people suffering from hyper acidity as it neutralizes the acidity of stomach.



c. Turmeric Powder (Besar)

Turmeric powder is widely used in our kitchen is a yellow coloured powder commonly
called ‘Besar’. It is obtained from the underground stem of turmeric plant. The
underground stem also called rhizomes are collected, cleaned and dried after cutting
into small pieces. Then these are ground to fine powder and is made ready to use.

Turmeric powder is used as spices in vegetables, pulses, pickles, fish, meat, etc while
cooking to make them attractive. It also provides various nutrients like proteins,
minerals, vitamins, etc. Because of its medicinal values it is also used in cosmetics
and medicines. Hot soup of turmeric, salt, cumin seeds, garlic, etc. is used in the

treatment of common cold.

Turmeric plant Rhizone Turmeric pieces Turmeric powser

d. Sour Juice (Chook/Amilo)

Concentrated sour juice which is also called as ‘ Chook’ or ‘Amilo’ is a common
chemical used in our kitchen. It is a dark thick liquid with strong sour taste. Chemically
it contains Citric acid. It is obtained from the juice of citrus fruits like lemon, lime,
etc. The juice is obtained by squeezing the citrus fruits and then it is boiled to obtain
thick dark coloured juice.

It is used to give sour taste to the pickles, vegetables, chutney, etc.It is a very good
source of vitamin ‘C’

Pieces of lemon Sour juice

118 Blooming Science & Environment Book 6

e. Yeast

Yeast is a unicellular, microscopic and non- green plant. It grows well in sugar rich
substances. Commonly it is used in our daily life in the form of ‘marcha’. It contains
vitamins B and E, proteins and an enzyme which converts various foodstuffs
containing carbohydrate into alcohol. Yeast is used to manufacture alcoholic drinks.
It is also used in baking bread, cakes, biscuits, etc.

Yeast plant Marcha Locally alcohol fermentation

f. Sugar

Sugar is a white crystalline substance used to make things sweet in our kitchen. Its
chemical name is sucrose. It is prepared by extracting and refining sugarcane juice.
Different fruits like grapes, banana, mango, apple, etc. also contain sugar in them.

Sugar available in the form of white crystals is soluble in water and sweet in taste. It
is used in making tea and various types of sweets, like laddu, peda, jeri, rasbari, etc.

It is also used to preserve some food items.

Sugar cane plant Sugar white crystals Sweets

g. Ghee

Ghee is the oily substance mainly used as the source of fat. It is made from the
animal’s milk. It is a semisolid substance at normal temperature. It is also prepared
from vegetable oil which is called vanaspati ghee or ‘Dalda Ghee’. Its chemical
name is Triglyceride. It contains mainly fat and different vitamins like A, D, E and
K. It is needed for our body in small quantity but excessive use of ghee or fat can be

harmful to our body.

Blooming Science & Environment Book 6 119

Main Points to Remember

1. Sodium Chloride (NaCl) is called common salt or kitchen salt and widely used
in cooking. The kitchen without salt is impossible nowadays.

2. Sodium Bircarbonate (NaHCO3) is a white crystalline solid which is also called
eating soda or baking soda and used in cooking and baking.

3. Turmeric is a herbaceous perennial plant of ginger family. It is yellow in colour
and used in cooking vegetables, dal etc.

4. Lemon is obtained from citrus plant, obtained in liquid form when squeezed. It
is used in vegetables, pickles etc.

5. Yeast is a microscopic plant that feeds on sugar and it is used in alcoholic
beverages like beers, spirits and wines.

6. Sugar is found in the form of white crystal and used to make various types of
sweets.

7. Ghee obtained from animals milk or vegetable oil is used as the source of fat.

PRO J ECTWORK

Make a list of chemicals used in your kitchen and mention their uses.

S.No Chemicals Uses

Exercises

1. Fill in the blanks.
a. Sodium chloride is commonly called .............................
b. The molecular formula of baking soda is .............................
c. ............................. is widely used in alcoholic beverages.
d. ............................. is used in tea to make it tasty.
e. Lemon juice is found in .............................fruit.

120 Blooming Science & Environment Book 6

2. Write true or false

1. Turmeric is yellow in colour with bitter taste.
2. Common salt is also called baking powder.
3. Sugar is found in crystalline form.
4. Lemon juice is obtained from citrus plant.
5. Yeast is a microscopic plant.
3. Match the following

Lemon NaHCO3
Yeast Spices
Baking soda
Ginger Citrus plant
Common salt
4. Answer these questions. Sodium chloride

Alcoholic beverages

a. Make a list of some useful chemicals used in our daily life and mention
their main use

b. What is common salt? Write its molecular formula and uses.
c. Write the uses of chook. From where do we get lemon juice?
d. Write 1/1 advantages of being used common salt and lemon juice.
e. Write few sentences about baking soda.
f. What is yeast? Write its uses.
g. Turmeric is called cash crops, why?
h. Draw a bud of yeast. It is called saprophytic, why?
i. Which vitamin and enzymes can be found in yeast?
j. NaCl is also called kitchen salt, why?
k. Which compound is used in bread?
l. Write down main uses of sugar and ghee.

Glossary

texture : quality
ingest : swallow
Ingredients : items of food
recipe : method
baking : boiling
thrive : flourish
aesthetic : visual
fermentation : breakdown of carbohydrate by micro-organism
pathogens : disease by virus or bacteria

Blooming Science & Environment Book 6 121

14Chapter Living Beings

Learning Outcome

On the completion of this unit, students will be able to: Estimated Periods: 12+2

 differentiate animals and plants on the basis of their physiological characters.
 classify animals and plants on the basis of their adaptation.
 observation and explain animals and plants on the basis of their habitat.
 differentiate dicotyledonous and monocotyledonous plants.
 classify the invertebrate animals.
 identify aquatic and terrestrial plants.
 explain the relationship between organism in the Scan for practical experiment

environment.
 outline the life spans of different types of plants.
 explain different types animals and their habitats.
 tell about phylum of invertebrates.
 explain about flower, seeds and their parts.

Biology and its Importance visit: csp.codes/c6e18

Biology is the systematic study of living beings. Plants and animals are the living
beings. Biology can be divided into two branches; Zoology and Botany. Zoology is
the study of animals and Botany is the study of plants. Biology is concerned with our
daily life. Even when we are working or enjoying ourselves, we are doing activities
related with biology. For example, a farmer who works in the field, not only know
about the plants, but also knows a lot about the insects in the farm. The gardeners
know a lot about the different kinds of flowers.

Activity

Observe some living-beings found in your surroundings. What are they? Where are
they found? What do they look like? What advantages and disadvantages do human
beings take from them? Discuss with your friends or teachers about the above questions
and find the answers.

We learn many things in Biology. There are living beings in our surroundings. Some
are advantageous and some are dangerous to us. From plants and animals we get food,
clothes, medicines, wood and raw materials for industries etc. There are some animals
which harm us like mouse, mosquito, monkey and poisonous snake. There are also
some plants which are harmful to us such as poisonous mushroom and weeds on the
field. There is no animal which is only harmful or only useful. Some are more harmful
but some of them are most useful.

122 Blooming Science & Environment Book 6

Mosquito Butterfly Sparrow Tiger

After studying these living beings we know a lot of things. For example, we know
about different ways of preparing medicines and their uses. Improved varieties of
plants and animals can be developed. And to get more and more advantages we should
put our full effort. To learn these all, we should study Biology.

Characteristics of Living Things

All the living things show the following characteristics:

1. Shape and size : All the living things usually have a definite shape, size and
appearance which help us in recognizing them.

2. Individuality : All the living things have their own identity i.e., they exist as a
complete unit. Their body cannot be separated out in parts as we cannot have
one half of a body.

3. Structural organization : All the organisms are made up of microscopic units
called cells. Cells are organized into tissues, tissues into organs, organs into
system and system into complete individual organism.

4. Metabolism : Living organisms acquire and utilize the energy. They need
energy for various activities through chemical changes taking place witching
the cells. This process is called metabolism.

5. Locomotion : Living organisms move here and there to perform their daily
activities [for food, recreation, etc]. The force for locomotion originates within
their body. The plants do not show movement to such a degree as the animals
do.

6. Growth : We are all familiar with the growth of a baby into an adult. Growth is
an increment in the cellular mass through the formation of new protoplasm with
or without the division of cells. Plants grow throughout their life. In contrast,
most animals have definite growth period.

7. Nutrition : All the living organisms require energy to perform their vital
activities. The process of getting food for liberation of energy is called nutrition.

8. Respiration : All the living organisms respire throughout their life as it is the
process of oxidation of foodstuffs for the liberation of energy.

Blooming Science & Environment Book 6 123

9. Adaptation : Adaptation is the process of adjustment in the environment. All the
organisms tend to adjust in their external environment.

10. Reproduction : It is an outstanding characteristic of the living beings. All the
living organisms reproduce again and again in their lifetime to continue their
generations. They reproduce by a variety of methods.

11. Age and death : All the living organisms have a definite age and after living
for a certain period, they will die.

Differences between Living beings and Non-living things

In our surroundings, things are separated into living beings and non-living things.
human beings plants and animals are living beings whereas a rock, water, air, table
etc and non-living things. Living beings are different from non-living things in many
ways. The table given below reflects the differences between the living beings and
the non-living things.

Differences between Living beings and Non-living Things

Living beings Non-living things
1. Living beings need food, air and
1. Non-living things do not need food,
water. air and water.
2. They respire.
3. They excrete. 2. They do not respire.
3. They do not excrete.
4. They are sensitive so they respond 4. They are not sensitive so they do
to changes around them.
not respond to changes around
5. They can move from one place to them.
other on their own.
5. They cannot move on their own.
6. They reproduce.
7. They grow. 6. They do not reproduce.
8. They are made up of cells. 7. They do not grow.
8. They are not made up of cells.
9. They have definite shape and size. 9. They do not have definite shape and

10. They have a definite life span after size.
which they die. 10. They do not have a definite life

span. They exist forever.

Activity

Observe five living beings and five non living-things around your surroundings. Try to
get their differences according to the table given above and write down the differences
you got. Discuss the ones you don’t know with your teacher.

124 Blooming Science & Environment Book 6

Differences between Plants and Animals

Plants Animals
1. Plants can manufacture their 1. Animals cannot manufacture their

own food by the process of own food. They obtain their food
photosynthesis. from plants or other animals.

2. Plants do not move from one place 2. Animals can move from one place to
to another. They are fixed to a place. another on their own.

3. Plants reproduce mainly through 3. Animals reproduce by giving birth to
seeds or spores. Some plants babies, by laying eggs or by dividing
reproduce through leaves, stem or their bodies into two parts.
roots.
4. Animals grow only up to a certain
4. Plants grow throughout their life. age.

5. Plants are less sensitive because 5. Animals are highly sensitive because
of the absence of sense organs and of the presence of sense organs and
nervous system. nervous system.

6. Plants have green colouring matter 6. Chlorophyll is absent in animals.
called chlorophyll.

A. Plant Life

Classification of plants on the basis of their habitat

An organism lives in a surrounding environment, which is known as its habitat.
Different plants have different types of habitat. According to their habitats, plants are
categorised into two types: i) Aquatic and ii) Terrestrial.

Aquatic Plants

Plants that grow in water are known as aquatic plants. These types of plants are called
hydrophytes. The body of these plants contains lots of air spaces that help them to float on
water.

Spirogyra Water hyacinth Hydrilla

Blooming Science & Environment Book 6 125

Lotus Water lily Vallisnaria

Their roots are poorly developed, but absorb minerals from the water. Their leaves
are broad, having big stomata that are able to transpire more amount of water from
the leaf. Their stems are poorly developed, soft and may be hollow inside.

The bodies of aquatic plants are covered with waxy substance that protects them from
decay. Such plants may be fully submerged in water or partly submerged or floating.
Aquatic plants are especially adapted to live in water. Some of them are flowering
and others are non-flowering. Spirogyra, water hyacinth, hydrilla, vallisnaria, lotus
and water lilly are some examples of aquatic plants.

Activity

• Discuss the different types of aquatic plants you have
seen.

• Observe different types of aquatic plants and discuss
their colour, shape, size, stems and roots, and compare
them with terrestrial plants.

Activity

To observe algae
Materials required: Pond water with scum, a glass slide, a microscope.
Method:

1. Collect some green scum from a nearby pond.

2. Put some drops of water containing the green scum on a
glass slide and observe under the microscope.

What happens?

Some green filament like structures are seen.
Conclusion

In the current of fast rivers, tiny algae encrust themselves onto the stones on the river
bed. In slower currents, by the bank, river plants anchor themselves firmly with roots.

126 Blooming Science & Environment Book 6

Terrestrial Plants

Those plants that grow on land are known as terrestrial plants. They have well-
developed plant bodies. According to the different climates, they are of different
types.

a. Plants of hot and wet climate

These plants grow in the coastal regions or on plain (Terai) regions of land, in
a warm and wet climate.

Rubber Coconut Papaya

These plants require more minerals and salts from the soil. They grow generally
tall .

b. Plants of hot and dry climate

These types of plants grow in the desert where the climate is warm and dry. Such
plants are called xerophytes. Their leaves are thick, having fewer stomata and
leaves are often reduced to spines or thorns, which decreases the transpiration
rate. They have fleshy stems with highly developed roots that help to absorb
water from the soil.

Aloevera Agave Cactus

Activity

Bring one potted cactus plant and discuss its different parts.

Blooming Science & Environment Book 6 127

c. Plants of moist and shady climates

Some plants need less sunlight and grow in moist and shady places, like under
trees or on hills. The plant body is not so well developed and they are non-
flowering plants. They are small in shape and size.

Mushroom Moss Marchantia Fern

d. Plants of cold climate

Some plants grow in cold climate with well developed roots and stems
and having narrow leaves, covering with wax (latex) which decreases the
transpiration rate. These plants are tall tree and some are small in size.

Cycas Thuja Pinus

Some types of cacti, such as the saguaro cactus, can expand their stems like concertinas.
This enables to hold as much water as possible when it rains.

Differences between Aquatic and Terrestrial Plants

S.No Aquatic Plants S.No Terrestrial Plants

1. They are also called water plants. 1. They are also called land plants.
Roots are highly developed.
2. Roots are poorly developed. 2. The stem is strong and hard.
Waxy substance is rarely found.
3. The stem is soft and flexible. 3.
The leaves have less and small
4. The plant body is usually covered 4. sized stomata.
with waxy substance. They are highly developed.

5. The leaves have numerous large 5.
sized stomata.

6. They are poorly developed. 6.

Classification of plants on the basis of their life span

The period of time that a plant remains alive is known as its life span. Plants grown in
different seasons and according to their life span (duration), they are of three types.
annual plants, biennial plants and perennial plants.

128 Blooming Science & Environment Book 6

a. Annual plants

These plants live only for a few months to one year. The life cycle of these
plants is completed in a particular season and then they die.

Mustard Potato Rice Maize Tomato

b. Biennial plants

Biennial plants live for two years or for two seasons They grow in the first
season and store food in their leaves, roots or stem. In the next season the
plants produce flowers, fruits and seeds after which they die, e.g. cabbage,
carrot, etc. However these plants behave as annual plants if they are grown in

the tropical and sub-tropical regions.

Radish Cabbage Turnip

c. Perennial Plants

Those plants that live for many years are called perennial plants. Every year
there is an increase in height and thickness of the plants. They bear flowers,
fruit and seeds every year. Trees like mango, banyan, etc. and shrubs like

lemon, hibiscus, etc are the examples of perennial plants.

Mango Guava Banana plant

Activity

Visit nearby garden and fields. Observe the plants like gram, pea, carrot, rose, maize,
rice, banana, tomato, bean, mustard and many others that are found in that area.
Discuss their characteristics. Separate the plants into annual, biennial and perennial.

Blooming Science & Environment Book 6 129

Monocotyledonous and Dicotyledonous plants

There are many plants in nature. Among these some produce flowers and some do
not produce flowers. The flowering plants are called phanerogams. The flowering
plants produce fruits and seeds from their flowers when they grow fully. The seeds
are developed inside the flowers. The plants like cycas, pine, etc. contain the seeds
but they do not have true fruits which enclose the seeds. But some plants like
mustard, pea, mango, maize, etc. contain the seeds in the fruits. Such plants are
called angiospermic plants. Shape and size of the seeds vary according to the plants.The
plants that have only one cotyledon in their seed they are called as monocotyledonous
plants. such plants have fibrous root system and have long narrow leaves with
parallel venation. Some plants have two cotyledons in their seeds and they are
called dicotyledonous plants. Such plants have tap root system and broad leaves
with reticulate venation. Pea, mustard, mango, orange, etc. are the example of
dicotyledonous plants where as maize, paddy, millet, banana, onion, etc. are the
examples of monocotyledonous plants.

Flower Terminal Bud Male
Steam Inflorescence
Fruit Female
Steam Inflorescence

Leaf
Leaf Sheath

Dicotyledonous plant Monocotyledonous plant

Differences between Monocotyledons and Dicotyledons

Monocotyledons Dicotyledons

1. The seeds have only one cotyledon. 1. The seeds have two cotyledons.

2. The plants with such seeds have 2. The plants having such seeds have tap
fibrous root system. root system.

130 Blooming Science & Environment Book 6

3. The leaves of such plants are narrow 3. The leaves of such plants are small
and long with parallel venation. and broad with reticulate (net like)
venation.

4. Examples: seeds of rice, maize, millet, 4. Examples: seeds of pea, gram, bean,

barley, wheat, etc. rose, pumpkin, cucumber, etc.

Main Points to Remember

1. Living things can be divided into two groups. They are plants and animals.
2. Each and every plant has its own habitat.
3. The surrounding environment where an organism lives is called its habitat.
4. Plants that grown in water are called aquatic plants or hydrophytes.
5. Plants that grown on land are called terrestrial plants.
6. Plants such as coconut and rubber grown in hot and moist climate.
7. Plants that are found in dry and hot climate are called xerophytes, e.g. cactus,

opuntia, etc.
8. Ferns and mushrooms are found in cool, moist and shady places.
9. Pine and dhupi are found in cold hilly climate.
10. On the basis of the duration of life cycle, plants are classified into annual,

biennial and perennials.
11. Annual plants complete their life cycle within one year.
12. Biennial plants complete their life cycle within two years.
13. Perennial plants live for many years.
14. Monocotyledonous plants have only one cotyledon in their seeds and

dicotyledonous plants have two cotyledons in their seeds.

PRO J ECTWORK

Collect the names of plants that you can recognize in your surrounding. To
recognize the plants take the help of your parents or teachers or seniors. Classify
the plants on the basis of different characteristics like flowering and non-flowering,
habitat, life span, seeds, etc. and make different tables to show the classification.
Submit your project work to york teacher and present in your class.

Blooming Science & Environment Book 6 131

Exercises

1. Write ‘T’ for correct and ‘F’ for the incorrect statements:

a. Coconut trees is found in desert.
b. Hibiscus is a biennial shrub.
c. Cactus cannot grow in dry regions.
d. Mango is a perennial plant.
e. Pine is found in hot climate.
f. Onion is a dicot plant.
2. Match the following:

Water lily moist and shady
Mango thorn
Opuntia broad leaf
Banana perennial
Fern poorly developed root
3. Fill in the blanks.

a. Opuntia grows in ……………… place.
b. Rice and wheat plants live for ………………….. season(s).
c. Plants that grown in deserts have …………………. stem.
d. The lotus plant has root, …………… and leaf.
e. Perennial plants live for ……………
4. Draw the diagrams of the following plants:

a. opuntia b. pine c.fern d. mushroom e. mustard

5. Answer the following questions:

a. Define terrestrial plants with examples.
b. What kind of plants are called aquatic plants?
c. Why is the stem of terrestrial plants strong?
d. Why is the stem of aquatic plants weak?
e. Why is the stem of aquatic plants waxy?
f. Why are the leaves of desert plants reduced to spines or thorns?
g. Terrestrial plants have well developed transport system. Why?
h. What kind of plant is called perennial plant?
i. What are xerophytes? Give examples.
j. Define hydrophytes with examples.

132 Blooming Science & Environment Book 6

6. Differentiate between:

a. Annual plants and biennial plants
b. Aquatic plants and terrestrial plants.
c. Manocot plants and dicot plants
7. Name any two:

a. Plants that float on water.
b. Plants found in cold climate
c. Plants that prefer dry and hot climate.
d. Moist and shade loving plants.
e. Plants that grow in mountain.
f. Dicotyledonous plants
g. Mono

8. Observe the following plants and write their names and habitats.

Glossary : The land along the edge of the sea or ocean.

Seashore : Tiny pores present on the surface of the leaves for the
Stomata exchange of gases.

Cuticle : The waxy layer that covers the aerial parts of a plant.
Tropical
Sub-tropical : The altitude of land below 1000 meter from sea level.

Adaptation : The altitude of land between 1000m to 2000m from sea
Terrestrial plants level.
Aquatic plants
Annual plants : adjustment of living things.
Perennial plants
: land dwelling plants.

: water living plants.

: Plants that survive only for one year.

: plants that survive for more than two years.

Blooming Science & Environment Book 6 133

B. Animal Life

Classification of animals on the basis of their habitat

Animals have different types of habitats. Their characteristics, external and internal
features are modified according to their habitat. According to the habitat, animals can
be classified into the followings groups.

a. Aquatic animals and

b. Terrestrial animals

Aquatic animals

These animals live in water. Their body is best suited to live in water. For this they
have developed some special body features.

The aquatic animals are also of two types.
1. Primary aquatic animals
2. Secondary aquatic animals

1. Primary aquatic animals: The animals that live in water are called aquatic

animals. These animals never had terrestrial ancestors. This includes varieties

of fish, snail, octopus, starfish, etc. Scan for practical experiment

visit: csp.codes/c6e19

The body of a fish is streamlined or boat shaped. It is covered with waterproof
scales. The body is provided with paired and unpaired fins for swimming and
tail for changing direction while swimming. They take dissolved oxygen from
water through the gills.

Some fish and water insects like giant water bug have swim bladder in their
bodies. Due to the bladder, they do not sink even when they stop swimming.

Sea horse Snail Octopus

134 Blooming Science & Environment Book 6

Shark Star fish

Snails, octopus, starfish, etc. are also aquatic animals and they all have
special body structure and modification for their survival.

Activity

Bring a fish from a market and study its scale, fins and tail. Identify the number of paired
and unpaired fins and note it down in your science note-book with an appropriate figure.

2. Secondary Aquatic animals: The animals which had terrestrial ancestors but
have adapted themselves for life in water are called secondary aquatic animals.
These include many groups such as Amphibian, e.g. frog. Reptiles, e.g. turtle,
crocodile, snake tortoise, etc. Birds like duck, penguin, crane, etc and Mammals
like dolphin, whale and seal, etc.

All these breathe in atmosphere. So crocodile, whale, dolphin take out their
head at certain intervals for taking oxygen from atmospheric air. As they are
adapted in water, their body shape is streamlined. Neck is reduced and external
ears have disappeared.

Penguin Frog Dolphin Turtle

Water birds have webbed feet for swimming. Amphibians like frogs are able
to live both on land and in water. In water they swim with their webbed feet
and breathe through the skin. On land, they breathe through lungs. Tadpoles
(larvae of frog) live completely in water and have fins and gills.

In whales and turtles, the limbs are modified into paddles which help them in
swimming in water.

Whale Turtle

Blooming Science & Environment Book 6 135

Activity

Look at the birds you find in water. Look at their feet and beak carefully. Also observe
parrot, pigeon, etc. their feet and beak. What difference do you notice? Note it down.

Birds Beak Feet
Duck
Parrot
Pigeon

Discuss with your friends
a. Why can some animals swim and some cannot?
b. Why don’t the birds have same type of beaks?
c. How do mosquito larva and tadpole turn into mosquitoes and frogs?

Activity

Collect water with some tadpoles and larva of Larva
mosquito from a nearby pond. Keep them in two Tadpole
separate vessels. Observe regularly to see the
development of frog and mosquito respectively.

Note down the changes you see with suitable
figures.

Terrestrial animals

Different animals on land have different habitats. Some stay in hot places and some
in cold. Some stay in holes underground. Animals, which stay in cold places have
long and thick hair, their feet are small but very strong. It is hard for them to live on
hot places.

Buffalo Rhinoceros

Elephant, buffalo, rhinoceros stay in hot places. Their body is covered with skin
only. They do not have long and thick hair on their body. Worms, snakes and rabbits
stay underground:

Birds also live in different places. Some live in hot places and some in cold. Animals,
which live on land, have lungs, skin and trachea to breathe. They have wings or feet

to move.

136 Blooming Science & Environment Book 6

Bird Snake Worm Rabbit

Some animals live in water, some on land and some fly. They also have different
characteristics. Animals which fly have streamlined body and wings to fly.

Activity

You know some birds live in hot and some in cold places. Name any five of each and
also write their similar and dissimilar characters.

Birds are flying

These are the animals that live on land. The terrestrial habitat is more varied than the
aquatic habitat. Animals living on land are divided in the following groups:

1. Animals living in cold climate: They have developed thick body surface with
thick and long hairs. They have a thick layer of fat just below the skin to keep
them warm in the cold climate.

Polar Bear Yak

Examples: Yak, Polar Bear,etc.

2. Animals living in hot climate: Their body is covered with thin hairs. Their
skin is thick.

As there is scarcity of water in hot climate they have to retain water for survival.
So, their skin can absorb moisture.

Blooming Science & Environment Book 6 137

Rhinoceros Buffalo Camel

Examples: Camel, Rhinoceros, Buffalo, etc.

Camel (the ship of the desert) can even live without water for many days in
desert. The running animals like tiger, dog, leopard etc. are also called cursorial
animals.

3. Aerial animals: These animals spend most of their time flying in air. These
are called aerial animals. The birds possess hollow bones, boat shaped body
(streamlined body), wings and tail for flying purpose.

Butterfly Sparrow Housefly

Examples: housefly, butterfly, sparrow, pigeon, dove, etc.

4. Arboreal animals: Animals like monkeys, squirrels, spend most of their time
in trees, are called arboreal animals. They have well developed palm with

fingers and grasping tail for the adaptation.

Monkey Squirrel

Examples : monkey, squirrel, etc.

5. Animals living in holes: They spend most of their life underground. i.e. in
holes under the ground. They have reduced eye sight. Mouth is usually pointed
to dig soil. They are also called fossorial animals.

Snake Earthworm Rabbit

Examples: earthworm, snake, rabbit, etc.

138 Blooming Science & Environment Book 6

6. Cave animals: The animals that live in caves are called cave animals. As there
is no sufficient light in caves, their eyes are reduced or become functionless.

They are adapted to starve or to live without food for a long time.

Scorpion Bat
Examples: scorpion, bat, mouse, slug, etc

Variation in animals on the basis of habit

All animals have to go in search of food for themselves and their babies. They do so at
a particular time of the day. On the basis of their habits, animals are divided into two
groups:

a. Diurnal Animals: The animals that are active during the daytime and take rest
at night are called diurnal animals.

Most birds, butterflies, dog, bear, human being, etc are the examples of the
diurnal animals.

b. Nocturnal Animals: The animals, which are active only during the night and
take rest during the day are called nocturnal animals. These animals can see
clearly even in dim light.

Cockroach, owl, different predators like lion, tiger, wolf, snake, earthworm,
fireflies, etc. are the examples of the nocturnal animals.

Main Points to Remember

1. The systematic study of living beings is called biology.
2. Living beings show fixed qualities like eating food, respiration, excretion,

sensitivity, movement and growth but non-living things do not show such
qualities.
3. When we are observing animals we know their food habit, movement, sensitivity
etc.
4. Animals have different body structure according to their habitat.
5. Aquatic animals breathe through gills or moist skin and terrestrial animals
breathe through lungs.
6. Animals living in cold climate have long and thick hairs.
7. Cave animals do not have functional eyes.
8. Fish have paired and unpaired fins to swim in water whereas whales have paddles.
9. Aerial animals have streamlined body, hollow and air filled bones and wings to
fly.

Blooming Science & Environment Book 6 139

10. Diurnal animals are active during daytime whereas nocturnal animals are
active during night.

11. There are differences between animals and plants. Plants differ from animals
in their mode of growth, food, movement, reproduction, sensitivity and cells.

12. We find different animals in different places.
13. Animals have different life styles and bodies.
14. In water animals respire through skin and gills. But on land, animals respire

through lungs, skin and tracheae etc.
15. All the birds cannot swim.
16. Animals which fly have stream-lined body and air spaces in them. They have

wings to fly.

PRO J ECTWORK

Collect the names of animals that you can recognize in your surrounding. (you can
take the help of your teachers, parents or seniors). Classify them on the basis of
their habitat. Show your work to the teacher and discuss in your class.

Exercises

1. Fill in the blanks.

a. The breathing organs of a fish are ……………………
b. In whales and turtles, the limbs are modified into …………..
c. The ………………… just below the skin keep the body of the animals of

the cold climate warm.
d. ………………….. of the cave animals are reduced or functionless.
e. Birds have ………………. body.

2. Tick mark (√) the correct statement and cross mark (x) for the wrong
statement.

a. A camel can survive without water for a long time.
b. A fish cannot breathe on land as it needs dissolved oxygen.
c. The paired and unpaired fins of a fish help it to swim in water.
d. A frog hibernates in winter season.
e. The heavy bones of a bird help it to fly.
f. Due to swim bladder, a fish can balance its body in water.
g. Arboreal animals spend most of their time in air.

140 Blooming Science & Environment Book 6

h. Earthworm is a cave animal.
i. Human beings are the examples of diurnal animals.
j. Cave animals are adapted to starving for a long time.

3. Match the following

Snow leopard soil animal
Snake hot climate
Frog hole
Rhinoceros snow
Earth worm hibernate
4. Answer these questions.

a. What is biology? Classify it.
b. Name the different divisions of animals according to their habitat.
c. What are primary aquatic animals? Give any four examples
d. What are secondary aquatic animals? Give any four examples.
e. Name any two animals found in cold climate
f. What are nocturnal animals? Give examples.
g. What are the common characteristics of aerial and arboreal animals?
h. Why do animals living in cold climate have thick and long hairs?
i. Why does a fish belong to primary aquatic animal group and a whale to

secondary aquatic animal group?
j. Define terrestrial animals with examples.
k. Define cursorial and fossorial animals with examples.
l. What are diurnal animals? Give examples.
5. Differentiate between

a. Terrestrial and aquatic animals
b. Primary aquatic and secondary aquatic animals
c. Plants and animals
6. Choose and copy the correct sentence only.

a. A crocodile takes out its mouth from water to breathe.
b. Yaks are found in Terai region only.
c. Amphibians can live both in water and on land.
d. A snake is basically an aquatic animal.

e. Habitat affects the structure and characteristics of animals.

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7. Identify the following animals and give a distinct characteristic of
each:

a. b. c.

d. e. f.

8. Write two examples of each:

a. Aerial animal
b. Animals live on trees
c. Animals that hibernate
d. Nocturnal animals.
e. Animals live in cave
f. Fossorial animals
g. Cursorial animals
h. Animals live in dry and hot places.
j. Animals which live in both land and water

Glossary

span : period

spore : a small sexual unit

slippery : very small

trachea : tube that carries air in insect

larva : one stage of life cycle

streamlined : boat shaped

burrow : a long hole under the soil

.

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C. Invertebrates

The surface of the earth is inhabited by a great variety of living organisms. Some
of them, such as amoeba or chlamydomonas are so small that they can be seen only
under the microscope. Others such as the whale or the banyan tree are so huge. A
general estimate number of species of living organisms existing today is more than
5 million. It is therefore very difficult to understand and remember about each and
every living organism. It is more precise to classify them into different groups on
common characteristics shared by all members of that group. Classification is the
arrangement of living beings into different groups on the basis of their similarities.

The great philosopher and biologist Aristotle was the first person to classify living
beings into plants and animals. He also classified all available contemporary animals,
so he is called the “Father of Biology”.

Animal Kingdom

There are large or small animals found in nature. On the basis of presence or absence
of vertebral column, animals are divided into invertebrates and vertebrates.

Animal Kingdom

Invertebrates Vertebrates

Protozoa Scan for practical experiment Pisces
Porifera Amphibian
Coelenterata Reptile
Platyhelinthes Aves
Nemathelminthes Mammals
Annelida
Arthropoda
Mollusca
Echinodermata

Invertebrates visit: csp.codes/c6e20

This group includes wide variety of simple structure animals. Invertebrate is
divided into nine phylum. Phylum protozoa includes unicellular animals but other
multicellular animals are included under metazoan. These animals are kept under
different phylum.

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1. Phylum - Protozoa (GK: protos = first, zoon = animals)

i. Animals which are made up of single cell: i.e. unicellular and cannot
seen by naked eyes (microscopic).

ii. They are mainly aquatic.

iii. All the vital activities like nutrition, excretion, respiration, etc. are
performed within the same cell.

iv. Locomotion takes place by pseudopodia or flagella or cilia.

v. Excretion takes place through the body surface or contractive vacuole.

vi. Reproduction takes place asexually by binary fission and sexually by
conjugation.

e.g. Amoeba, Paramecium, Plasmodium, Euglena, Plasmodium, etc.

Amoeba Euglena Paramecium

2. Phylum: Porifera (Lat. Porus = Pore, ferre = to bear)
i. The body is multicellular and diploblastic.
ii. They are aquatic and attached to substratum.
iii. The body surface bears numerous pores, called ostia. Water enters

through these pores.

iv. A large opening, the osculum is present at the top through which water is
thrown out.

v. Digestion is intercellular (within the cells)

vi. Respiratory, excretory and nervous system are not developed.

vii. Reproduction takes place by asexual (budding) and sexual both ways.

viii. They possess a great power of regeneration.

e.g. Sponge, sycon, etc.

Sycon Sponge (eusponge)

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3. Phylum: Coelenterata (GK., Koiles = hollow, enteron = intestine)

i. They are aquatic found in pond, well, sea etc.

ii. Some are attached with the substratum in water, while other are free
swimming.

iii. They are multicellular, diploblastic (two layers of cells) animals.

iv. A body cavity called coelenterons represents the digestive tube.

v. Mouth is surrounded by tentacle which helps in locomotion and
capturing food. It absorbs essential components and removes
unwanted substances from mouth.

vi. Reproduction takes place by asexual and sexual methods.

vii. Stinging cells are present on their tentacles which help to take food.

viii. Respiratory, excretory and circulatory systems are absent.

e.g. Hydra, obelia, corals, jellyfish, etc.

Hydra Sea anemone Jelly-fish

4. Phylum - Platyhelminthes (Gk. Platys = flat, helminth = worm)
i. They are dorsoventrally flat, unsegmented animals.
ii. They are triplobalstic ( 3 layer of cells).
iii. The body cavity or coelom is absent.
iv. They are mostly hermaphrodite.
v. Locomotary organs, respiratory, circulatory systems are absent.
vi. Sucker is present around the mouth but anus is absent.
vii. They are bilaterally symmetrical.
viii. Most of them are parasitic and few are free living and attached to stones.
ix. They cause various diseases in mammals.
e.g. Liver fluke, tapeworm, planaria.

Liverfluke Tapeworm

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5. Phylum-Namathelminthes or Aschelminthes (GK. nema = thread,

helminthes = worm)

i. They consist of mouth, anus and sucker.

ii. Most of them are free living and some are parasites
on plants and animals.

iii. Most of them are aquatic in fresh water, marine
water or terrestrial in soil.

iv. They lack respiratory and circulatory system.

v. These are unisexual, i.e. sexes are separated. Ascaris

vi. Body can be divided into two equal halves
(bilaterally symmetrical).

vii. Alimentary canal is straight with mouth and anus.

e.g. Ascaris, hookworm

6. Phylum - Annelida (annelus = ringeidos form)
i. The animals have long, cylindrical and segmented body.
ii. They are found on land in moist and damp places.
iii. Body skin is moist and respiration takes place through skin.
iv. Alimentary canal is well developed from mouth to anus.
v. Brain and nerve cells are well developed.
vi. Excretion and blood circulation organs are developed.
vii. They are hermaphrodite.
viii. Body can be divided into two equal halves i.e. bilaterally symmetrical.
ix. Locomotion is carried out by bristle or setae.
x. Body is triploblastic.

e.g. Earthworm, leech

Leech Earthworm

7. Phylum Arthropoda (GK: Arthros = jointed, podos = foot)

i. It is the largest phylum in animals.
ii. They are terrestrial, aquatic and as well as aerial.
iii. They bear joint appendages.
iv. Body is divided into three parts. i.e. head, thorax and abdomen. Some are

having fused head and thorax. i.e. cephalothorax.
v. Alimentary canal is well developed from mouth to anus.

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vi. Some have wings.
vii. Sexes are separate.
viii. Mainly life cycle completes in four stages. i.e. egg, larva, pupa and adult.

ix. Phylum includes honey bee, ant, millipede, centipede, mosquito, etc.

Crab Scorpion Cockroach Butterfly

Arthropod is divided into four classes: Crab

a) Crustacea: They are aquatic. Head is often fused with thoracic
segments to form cephalothoraxes. Respiration through gills or
body wall. Jointed appendages, are present, eg. crab, lice, cray fish,
etc.

b) Insects: They are terrestrial, body is divided into three regions
head, thorax and abdomen. They have three pairs of jointed legs
and two pairs of wings, eg. grasshopper, houseflies, cockroaches
etc. Cockroach

c) Myriapoda: They are terrestrial. Body is cylindrical and
segmented, each segment bears one of two pairs of legs, eg.
centipede, millipede etc.
Millipade

d) Arachnida: Mostly are terrestrial. Body is divided into
cephalothorax and abdomen. There are six pairs of appendages
on cephalothorax, eg. spider, scorpion, etc.

Scorpion

8. Phylum Mollusca: (Lt. mollis = soft)
i. They have soft and unsegmented bodies.
ii. They are aquatic (fresh water or marine) and terrestrial.
iii. Some animal’s body is covered by hard shell which is made up of calcium.

They have muscular feet for locomotion but in octopus tentacles help in
locomotion.
iv. Head of some animals may consist of tentacles.

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v. They are very sensitive to external stimuli like touch.

vi. Digestive, blood circulatory, excretory and nervous systems are well
developed.

vii. They are mostly unisexual.

viii. The body is usually divided into head, visceral mass and muscular foot.
e.g: Octopus, snail, slug, cuttle fish, unio, etc.

Snail Octopus Oyster Cuttlefish

9. Phylum Echinodermata (GK; Echinos = spiny, derma = skin)
i. Body is covered with spine which is made up of calcium carbonate.

These spines are very hard and are found on the dorsal side of body.
ii. They are aquatic and found in sea.
iii. They are unisexual.
iv. They have radially symmetrical body.
v. Star fish consists of five arms which looks like as star.
vi. A distinct head is absent and mouth lies on the ventral surface.
vii. Feeding and locomotion takes place by the tube feet.
e.g. Starfish, sea urchin, sea cucumber etc

Starfish Sea urchin

Main Points to Remember

1. The animals without backbone are called invertebrates and the animals with
backbone are called vertebrates.

2. Protozoa are microscopic in nature.
3. Porifera are pore bearing animals. They are commonly called as sponges.
4. Coelenterates have sac-like hollow body cavity called as coelenteron.
5. The word platyhelminthes is made of two sub words- ‘platys’ meaning ‘flat’

and ‘helminthes’ meaning ‘worm.’ These are flatworms.

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6. Nemathelminthes are commonly referred as round worm.
7. Annelida consists of animals which are mostly aquatic, marine or fresh water.

Some are burrowing or parasite and some are free living.
8. Arthropods are animals with jointed leg.
9. Molluscs are the soft bodied animals which show no segmentation.
10. Echinodermata are marine animals which possess spiny skin.

PRO J ECTWORK

1. Draw a tree sketch of animal kingdom in a chart paper and show to your
teacher.

2. Collect 10 different pictures of invertebrates and write their phylum and
one characters of each.

Exercises

1. State whether the following statements are true or false:

a. Animals are found in different shapes and sizes.
b. Animals with backbone are known as invertebrates.
c. Arthropods have six legs.
d. Mollusca have segmented body.
e. Porifera have pores.
2. Match the following:

Coelenterates Soft body

Platyhelmintes Spiny skin

Nemathelminthes Pores bearing

Annelida Sac-like body

Protozoa Flat worms

Mollusca Round worms

Echinodermata Segmented body

Porifera Unicellular

3. Name any two animals of the following types:

a. Protozoa b. Porifera c. Coelenterates
f. Arthropods
d. Annelids e. Mollusca

g. Echinodermata

4. Answer the following questions in brief:

a. What are the two important sub kingdom of animal kingdom?
b. What are vertebrates? Give examples.

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c. What are invertebrates? Give examples.
d. How many types of invertebrates are there?
e. What are the characteristics of roundworm?
f. Give any two important features of porifera.
g. Why platyhelminthes are called as flat worms?
h. “Snail is Mollusca”, how can you say this?
i. Which group of animals contain the largest number?
j. Define the term parasite with examples.
k. What are hermaphrodites?
5. Write two characters of each of the following.

a. Coelenterates b. Platyhelmintes c. Nemathelminthes
f. Mollusca
d. Annelida e. Protozoa

g. Echinodermata h. Porifera

6. Name the phylum of given animals.

amoeba, hydra, sponge, jellyfish, tapeworm, earthworm, ant, cockroach, snail,
starfish, liverfluke

7. Write down the differences between the followings.

a. Protozoa and metazoa b. Snail and earthworm
c. Jelly fish and star fish.

Glossary

unicellular : single celled organism
multicellular : having more than two cells
invertebrates : animals without backbones
aquatic : living in water
saprophytic : a plant grows on dead organic matter
porifera : animals having large pores in their bodies
mollusca : soft bodies and segmented animals
arthropods : a group of insects

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