Download important facts and handy facts physics chapters. motion and electric

IMPORTANT FACTS AND HANDY FACTS
PHYSICS CHAPTERS.
MOTION AND ELECTRIC CURRENT AND ITS EFFECTS
Motion is relative as it is always described with
respect to some other object. For Eg. Earth is moving
with respect to sun, A car is moving on the road with
respect to stationary trees.
What are the different types of motion?
Rectilinear: Motion of soldiers moving in a march
past.
Circular: Motion of the merry go round.
Rotational Motion: Earth moving on its own axis.
Vibratory: String of a guitar.
Oscillatory: Motion of a simple pendulum.
When a body covers equal distance in equal interval
of time and it has a constant speed, then it is said to
have Uniform motion.
When a body covers unequal distance in equal
intervals of time and it does not have a constant
speed, then it is said to have a non uniform motion.
Electric Current: The flow of electric charge is called
electric current. In an electric circuit, the charge is
often carried by moving electrons. The SI unit of
electric current is Ampere (A). The SI unit of electric
charge is Coulomb.
Electric Circuit:The path through which electric
charge moves is called electric circuit.
Symbols in Electric Circuit: Different components of
electric circuit are shown by certain symbols. Use of
symbols makes it easy to represent an electric circuit.
Use of standard symbol makes it easy to understand
for anybody. For example; a TV mechanic can
identify different components of a TV by looking at
its circuit diagram.
.
Time Measurement Devices
SAND CLOCK,WATER CLOCK,SUN DIAL,PENDULUM
STOP WATCHES AND CLOCKS.
Sun Dial: It works on the principle of shadow of
gnomon formed on the surface.
Pole of sundial is known as Gnomon.
• Disadvantages:It does not work on cloudy days
and during the night time.Generally ,it does not
give time in seconds
Pendulum:
Metal Ball of pendulum is known as bob.
Oscillation: 1 complete to and fro motion of the
metal bob is known as oscillation.
Time Period: Time taken to complete 1
oscillation is known as Time Period.
Frequency: Number of oscillations which take place
in 1 second is known as frequency.
Electric Cell: It is a device which produces electric
charge because of some chemical reactions. The
cell which is used in a torch is called dry cell. The
wet cells are used in car batteries. A normal dry cell
gives an output of 1.5 Volt (V).
Battery: A group of cells is called battery. More than
one cell is used in most of the devices; because
these devices need more than 1.5 V of power.
Closed Circuit: When the circuit is complete, it is
called closed circuit. Current flows only in a closed
circuit. Open Circuit: When the circuit is
incomplete, it is called open circuit. Current does
not flow in an open circuit.
Time Period of a pendulum depends on Length of a
pendulum. Galileo Galilei found that time period of
a pendulum is fixed if the length of a thread is fixed.
Stop Watch and Quartz Watch.
These watches are very accurate.
Stop watches can measure time upto milli seconds.
DISTANCE TIME GRAPHS
Distance time graph for a uniform motion is a
diagonal straight line.
Distance time graphs for a non uniform motion
is a curve.
Distance time graph for a ody at rest is a
straight horizontal line parallel to time axis.
Heating effect of current
When electric current flows through a conducting
wire, the temperature of wire increases. This is
called heating effect of electric current.
Devices Which Work on Heating Effect of Electric
Current:
Incandescent bulb is an example of a device which
works because of the heating effect of electric
current. The filament of bulb is made of tungsten.
Tungsten has very high melting point and that is
the reason it is used in electric bulb. Moreover,
argon gas is filled inside the bulb. Argon prevents
the filament from catching fire. Electric iron, water
heater, geyser, toaster, etc. are some other
devices which work on heating effect of electric
current.
ELECTRIC CURRENT AND ITS EFFECTS CONTINUED..
Elements of Heating Appliances:
A heating appliance has a highly coiled wire or a
metallic rod. The highly coiled structure increases the
surface area and thus provides more heat. The
elements are usually made of constantan which is a
metal with very high melting point.
Electric Fuse:
Electric fuse is a safety device which is used in
household wirings and in many appliances. Electric
fuse has body made of ceramic and two points for
attaching the fuse wire. The fuse wire melts
whenever there is overload in the wiring. This breaks
the circuit and helps in preventing damage to costly
appliances and to the wiring. In electrical devices a
glass fuse is often used. This is a small glass tube, in
which lies the fuse wire.
Electric Bell: Electric Bell is composed of two rods of
cast iron. Coil is made around the iron rods. A
metallic strip is placed parallel to the coils. The
metallic strip is fitted with a hammer at one end.
Another end of the strip is connected to the circuit. A
gong is placed in a position so that it can be hit by
the hammer. When current flows in the circuit, the
cast iron rods become electromagnet and attract the
metallic strip. The metallic hammer hits the gong
because of that. Once the metallic strip is pulled
towards the electromagnet, it gets disconnected
from the point and there is a break in the circuit. A
spring pulls the metallic strip back because no
magnetism is left in the electromagnet. This cycle
continues and the electric bell produces a ringing
sound.
MCBs (Miniature Circuit Breaker):
MCBs have been replacing electric fuse from
wirings at most of the places. The electric fuse
has a big practical problem. Whenever the wire
fuses, one needs to replace the wire to resume
electric supply. More often than not, this proves
to be a cumbersome task. Miniature circuit
breakers break the circuit automatically. One
just needs to switch it on to resume the electric
supply. Many models of MCBs have a built in
mechanism by which the electric supply is
automatically resumed.
Short Circuit and Overloading:
Short Circuit: When live and neutral wire gets
connected, current exceed the safety limit and the
amount of heat produced increases heavily leading
to fire.
Overloading: When too many appliances gets
connected to a single socket, the amount of
current5 exceed the safety limit. It leads to a
situation of short circuit.
Magnetic Effect of Electric Current: Hans Christian
Oersted (1777 – 1851) was the first to show that
electric current also produces magnetic effect. He
kept a magnetic compass near a current carrying
conductor. It was observed that the magnetic
compass shows deflection, when the current passes
through the conductor.
Electromagnet: Magnetic effect of electric current
has been used in making powerful electromagnets.
For this, wire is wrapped around an iron rod in many
turns and electric current is supplied to the wire. As
long as the current is supplied the iron rod behaves
like a magnet. More number of turns makes more
powerful magnet. Electromagnet is used in electric
bells and also in powerful cranes.
In order to avoid damage due to short circuit and
overloading, fuse is used. Fuse is a safety device
which melts and break the circuit when current
exceeds the safety limit.
Fuse is connected in series to the live wire to
avoid fire caused due to short circuit and
overloading.
LIGHT
Light travels in a straight line.
The ray of light which strikes the surface is
called the incident ray.
• The ray of light which leaves the surface is
called the reflected ray.
• A line perpendicular to the surface is
imagined at the point of reflection.
• The angle between the incident ray and the
normal is called the angle of incidence.
•
The angle between the reflected ray and the
normal is called the angle of reflection.
Angle of incidence=Angle of reflection
The incident ray, reflected ray and the normal all lie
on the same plane.
These are the Laws of reflection of light.
•
Reflection:Bouncing back of light when it is
incident on the reflecting surface.
The ability of mirrors to make left of an object
appear right and vice versa is known as lateral
inversion.
Spherical Mirrors:
•
CONVEX MIRROR:
Image is formed behind the mirror (virtual image)
It is right way up( erect)
It is smaller in size.
CONCAVE MIRROR:
Image is formed on the screen when the object is
away from the mirror. It is real and inverted
When the object is very close to the mirror, image
formed is virtual, erect and magnified.
•
DISPERSION OF LIGHT: Newton had shown
that light rays that we obtain from the sun
consist of seven different colours – red,
orange, yellow, green, blue, indigo and
violet. When rays of the sun are made to
pass through a glass prism, we will see the
seven different colours.
Why is an image formed by a plane mirror?
An image is formed because light emanates from
an object in a variety of directions. Some of this
light (which we represent by rays) reaches the
mirror and reflects off the mirror according to
the law of reflection. Each one of these rays of
light can be extended backwards behind the
mirror where they will all intersect at a point (the
image point). Any person who is positioned along
the line of one of these reflected rays can sight
along the line and view the image - a
representation of the object.
Image is formed behind the mirror and that to
not by the actual intersection of reflected rays.
So, it is a virtual image. It is erect image. It is of
the same size as us. It is at the same distance
from the mirror as we are from the mirror.
A rainbow is seen when the sun appears in the sky
after the rains. The moisture in the atmosphere
behaves like tiny prisms, dispersing the sun’s rays
into seven colours (Vibgyor). The red colour
appears on the top of the rainbow and the violet
colour appears at the bottom. A Newton disc is a
disc with segments in rainbow colours. When the
disc is rotated, the colors fade to white; In this way
Isaac Newton demonstrated that white light is a
combination of the seven different colors found in
a rainbow. A Newton Disc can be created by
painting a disc with the seven different colors. A
combination of red, green and blue in the circular
disc will yield the same result. This is due to the
phenomenon called persistence of vision.
WIND, STORMS AND CYCLONES.
1.
What is wind? What is the cause of wind?
Moving air is called wind. Air moves from
high pressure region to the low pressure
region. It is caused due to the difference in
air pressure between the two places. Due to
the heat of the sun air becomes warm,
producing a low pressure. So, the warm air
rises up and the cool air from
the surrounding moves towards the area.
2. What is cyclone and how is it formed?
A. Winds blowing at a speed of 120 km per
hour or above are known as cyclone. A cyclone is
known by different names in different parts of
the world. It is called ‘hurricane’ in the American
continent. It is called typhoon in Japan, China
and Philippines. In Australia, it is called WillyWillies.
Summer Monsoon Winds: In summer near the
equator, the land become warm and the
temperature of the land increases. The air above the
land becomes warm and rises up. This causes the air
from the ocean blow towards the land. These are
known
as
Summer
Monsoon
Winds.
Winter Monsoon Winds: In winter, the direction of
the wind flow gets reversed. It blows from the land
to the oceans. These are known as Winter Monsoon
Winds.
5.
What is Thunderstorm? Thunderstorms
develop in hot, humid tropical areas very frequently.
The rising temperature produces strong upward
rising winds. These winds carry water droplets
upward. At a certain height these tiny water droplets
freeze and fall down again.
Formation of cyclone: The formation of cyclone is a
very complex process. Due to heat of the
atmosphere water gets evaporated and changes to
water vapour. When water vapour changes back to
water due to condensation, the heat is released to
atmosphere and warms the air around. Then the hot
air rises up causing a drop in pressure. More air from
surrounding regions not only rushes in but also starts
spiraling. This cycle is repeated. This chain of events
ends with the formation of a very low-pressure
system with very high speed winds evolving around
it. This weather condition called a cyclone. Factors
like wind speed, wind direction temperature and
humidity contribute to the development of cyclone.
3. What are the different reasons for wind
current?
A. The different reasons for wind currents are :
i) Uneven heating between the equator and the
poles due to shape of earth and its inclination.
ii)
Uneven heating of land and water.
Because of their swift movement, the water and ice
particles rub against each other and build up a
negative electric charge in the cloud. The electric
charge is then released by the clouds by the stroke
of
lightning
and
thunder
is
produced.
6. What are the precautions in thunderstorms?
A. The precautions in thunderstorms are as below.
1. It is well advised not to take shelter under an
isolated tree, because an isolated tree is prone to
lightning. While in a forest, it is advised to take
shelter under a small tree.
2. Do not lie on ground.
3. Do not take shelter under an umbrella with a
metallic rod, as pointed metallic materials are
prone to lightning.
4. Do not sit near a window. Open garages,
storage sheds, metal sheds are not safe places to
take shelter.
5. If one is in water, he should get out and go
inside a building.
6. A bus or car is a safe place to take shelter
.7.
What are tornadoes?
A.
A tornado is a dark funnel shaped cloud
that reaches from the sky to the ground. The neck
of the funnel sucks up anything which comes in
its way. The tornadoes may form within cyclone.
The wind in a violent tornado can circle around at
a speed of 300 km per hour.
4. What are monsoon winds?
A. The seasonal winds bring rain between June and
September in India and South Asia are known as
Monsoon winds.There are two types of monsoon
winds.
They
are
1.
Summer Monsoon winds ( Sea breeze)
2.
Winter Monsoon wind ( Land breeze)
8.
What
is
eye
of
a
storm?
A.
The centre of a cyclone is a calm area. It is
called the eye of the storm. The diameter of the
eye varies from 10 to 30 km. It is a region free
of clouds and has light winds.
9.
Steps taken by government for cyclone
warning.
A.
The steps taken by government for cyclone
warning
are
as
under.
1.With the help of Satellite Weather Observation
Radars, the formation of cyclone, its direction and
intensity is detected by the meteorological
department.
2.
The news of the formation of cyclone , its
direction and intensity etc is immediately
telecasted and broadcasted at least 48 hours
before the arrival of the cyclone.
3.Cyclone warning is telecasted and broadcasted
every
hour
or
half
hour.
10. Describe the action on the parts of the
people.
1. We should not ignore the warning issued by
the
meteorological
department through
television, radio or news papers.
2. We should make necessary arrangement to
shift the essential household goods, domestic
animals and vehicles etc to safer places.
3.Avoid driving on roads through standing water.
4.Keep ready the phone numbers of all
emergency services like police, fie brigade and
medical centers.
11. What are the other precautions if you are
staying
in
a
cyclone
hit
are?
A. The precautions in a cyclone hit area are as
under.
1. Do not drink water that could be contaminated.
Always store drinking water for emergency.
2. Do not touch wet switches and fallen power
lines.
3. Do not go out just for the sake of fun.
4. Do not pressurize the rescue force by making
undue
demands.
5. Cooperate and help your neighbours and friends.
HEAT.
Transfer of heat:Heat is transferred by conduction,
convection and radiation.
Conduction:Transfer of heat from one particle to
the adjacent particle. In solids, heat is transferred
by the process of conduction. In this process, the
transfer of heat takes place through adjacent
molecules.
Ex: When one end of an iron rod is put over flame
then part which is nearer to the flame is heated
first and heat is gradually transferred to the other
end of the rod. This happens because particles of
iron rod which are nearer to the flame receive the
heat and transfers this to the adjacent particles.
Subsequently, the adjacent particles transfer the
heat to the next adjacent particles. This process
continues and heat reaches to the other end of the
rod. Thus, heat transfer in solid takes place through
conduction.
Convection in air: Air gets heated because of
convection; the way water gets heated. Air near the
source of heat gets heated and rises above. This
leaves a gap; which is filled by the colder air from
the surrounding. The convection current thus starts
in air which results in heating up of air.
When you place your palm above a flame you will
feel the hotness of the flame. But when you will
place your palm below the flame the area will be
colder. This shows how the colder air from below
moves up; due to convection current.
Conductor and Insulator:
Materials which allow heat to pass through it are
called conductor or good conductor of heat, such
as iron, copper, aluminium, etc. All metals are good
conductors of heat. Since, mercury is a metal and
found in liquid state at room temperature, that’s
why it is used in thermometer.
Since metals are the good conductor of heat that’s
why kitchen utensils are made of metals or alloys of
metals.
Materials which do not allow heat to pass through
them are called bad conductor or poor conductor
of heat. They are also called insulators. Example:
rubber, wood, plastic, etc. This is the cause that
handles of frying pan or other kitchen utensils are
made of plastic.
Land and Sea Breeze:
Sea Breeze: In coastal areas, the breeze that
moves from sea surface to the land is called sea
breeze. This happens because, during daytime,
land gets heated more quickly than water. As a
result, warm air from land rises up; leaving a gap.
To fill that gap, colder air from the ocean surface
rushes towards the land. This phenomenon
continues and a continuous flow of cold air keeps
coming towards the land. This gives rise to the
phenomenon which is called the sea breeze.
Because of this, people living in coastal areas
prefer to live in a sea facing house.
Convection:
The transfer of heat because of movement of the
molecules of the medium; via mass transfer; is called
convection or convection of heat.
Water and air are bad conductors of heat. But they
do become hot, in spite of being bad conductors.
Heat transfer in fluids takes place through
convection.
Convection in water: When water is heated in a pan,
the particles of water which are near the source of
heat; get heated first. Because of heating, they
become light; and rise in water. The gap which is
created because of rise of hot particles is filled cold
particles of water from the surrounding area. Thus a
cyclical movement of particles begins and ends up
heating the whole water of the pan. The cyclical
movement in fluids because of heating is called
convection current.
Land Breeze: In coastal areas, the breeze which
moves from land towards the sea is called land
breeze. In the night, the land cools down more
quickly than the ocean surface. This makes the air
over the water surface warmer than air over the land
surface. Warmer air over the water surface rises in
the air and air from the land rushes towards the
water surface to fill the gap. This phenomenon
continues which creates a flow of air from land to the
sea. This phenomenon is called land breeze.
Radiation:
All hot bodies emit heat by the process of radiation.
Radiation of heat does not require a medium.
Sunlight comes to the earth because of radiation as
there is no medium present between the
atmosphere of the earth and the sun.
One can feel the heat of bonfire by standing around
it. We get warmth from the room heater because of
radiation.
Reflection and absorption of heat: When heat falls
over an object some of the heat is absorbed by the
body and some of the heat is reflected. The
temperature of an object increases because of
absorption of heat.
In conventional room heater you can see the
reflector attached with it. The reflector of the
room heater reflects the heat towards the person
sitting or standing near the room heater.
Reflection is the cause that umbrella is used to
protect from heat of the sun in summer. Dark
color absorbs more heat while light color reflects
most of the heat. That’s why wearing light colored
clothes is preferred in summer, dark colored
clothes are preferred in winter.
Dark clothes absorb more heat and keep one
comfortable in winter. On the other hand, light
clothes reflect most of the heat and keep one
comfortable in summer.
Heat
Heat is the transfer of energy from a hot body. The
sense of touch is not reliable and cannot be always
used to say how much hot anything is. Thus, hotness
of anything is measured in terms of TEMPERATURE
in reliable way. To measure temperature a device
called THERMOMETER is used.
Unit of heat:There are three units which are used to
measure the temperature: Degree Celsius,
Fahrenheit and Kelvin.
Degree Celsius: Degree Celsius is written as °C and
read as degree Celsius or simply Celsius. For
example 20°C; it is read as twenty degree Celsius.
Fahrenheit: Fahrenheit is written as °F and read as
degree Fahrenheit. For example 25°F; it is read as
twenty five degree Fahrenheit.
Kelvin: Kelvin is written as K. For example 100K; it is
read as hundred Kelvin.
Thermometer: Thermometer is a device which is
used to measure temperature
Now-a-days many kitchen utensils come in black
color, since utensils of black color absorb more
heat and thus cooking becomes faster.
Woolen Cloth: Woolen clothes are used in winter
season. Wool is a poor conductor of heat. In
addition to it; air gets trapped in woolen fiber to
further increase the poor conductivity of wool.
This prevents the radiation of heat of our body to
the surrounding and prevents the cold from
surrounding to affect our body. Thus, wearing
woolen cloth makes one comfortable in winter
season.
Thermometer is made of a long narrow glass tube;
with a bulb at one end. The narrow tube appears as
a continuous silver line; because it is filled with
mercury. Mercury is a metal which is in liquid state
at room temperature and it readily expands or
contracts at the slightest change in temperature.
Hence, mercury is used in thermometer.
Types of thermometer:
Laboratory Thermometer: is used to measure the
temperature. The scale of temperature is
graduated generally from –10°C to 110°C over the
glass tube. Each division of temperature scale is
further divided into 10 parts to read fraction of
temperature.
The end of the silvery thread shows the reading of
temperature. If mercury lining ends at 37, the
reading is 37°C.
4.Wash the bulb end of thermometer with an
antiseptic solution.
5.Give two or three jerks slightly. By doing this the
mercury level would fall. When it falls to 35°C or
below, put it below the tongue and wait for one
minute.
6.Take out the thermometer and read the
temperature. Temperature would be near 37°C.
7.The normal body temperature is 37°C. This can
differ from person to person.
Use of Laboratory Thermometer:
1.Take some water in a beaker.
2.Take a laboratory thermometer and 3.Immerse its
bulb end in water; holding it vertically. Ensure to dip
whole portion of bulb end. The bulb end should not
touch the bottom or side of the beaker.
4.Observe the movement of rise of mercury. When
it becomes stable, take the reading of the
thermometer.
5.Mark the reading when the thermometer is inside
the beaker only.
Clinical Thermometer: Clinical thermometer is used
to measure the body temperature. The scale of
temperature is graduated from 35°C to 42°C and or
from 94°F to 108°F. The temperature of human
body always remains within this range and this is
the range on the clinical thermometer. There is a
kink make near the bulb of clinical thermometer
which prevents the automatic fall of mercury level.
Maximum-Minimum Thermometer: Maximum –
minimum thermometer is used to measure the
daily temperature to prepare weather reports
Digital Thermometer: In digital thermometer,
reading of temperature is displayed digitally as
in digital watches. This is safer because no
mercury is used in this. It is important to note
that mercury is a highly toxic substance.
Precautions while using thermometer:
1.Take a clinical thermometer and hold it
horizontally with reading scale towards your
eye.
2.Do not hold the thermometer from the bulb.
Rotate the thermometer slightly clockwise and
anticlockwise. By doing this you will see a shiny
thin silvery thread.
CHAPTER- GARBAGE IN, GARBAGE OUT
Question 1- Why is disposal of garbage an
immense problem?
Answer- It is an immense problem because of the
amount of garbage generated. If it is burnt , it
generates smoke and poisonous gases, which
pollute the air. If it is thrown into river or the sea,
it pollutes the water. If you deposit it on the land,
it pollutes the land and also affects the quality of
groundwater.
SEGREGATING WASTES
*The first step in disposal is to segregate the garbage
into biodegradable and non biodegradable wastes.
*Segregation of wastes is necessary because the two
kinds of waste require different methods of disposal.
*Segregation has to start from home so every house
should have two garbage bins- one for biodegradable
wastes and the other for non biodegradable wastes.
*In some cities , the municipality provides two
different colored dustbins- blue for garbage that can
be recycled and the green for biodegradable wastes.
RECYCLING BIODEGRADABLE WASTES
VERMICOMPOSTING
• Biodegradable wastes can also be recycled into
compost by another method for composting, using a
type of worm called red worm. They look like
earthworms.
LANDFILL
•
•
A low lying area of landfill is a site of
disposal of waste materials by burial and is
the oldest form of waste disposal
At the landfill, the useful part of the garbage
is separated out and the non-useful part is
spread on the ground and covered with soil
and when the landfill site is completely
filled, it is converted into park or a
playground
REUSING AND RECYCLING PAPER
Tear waste paper into small pieces and put them in a
blender .Add some water and run the blender to get the
paper pulp. Pour the pulp in the tub that already has
water in it, and let it stay undisturbed for a few hours.
Take out the pulp portion with the help of a wire mesh
strainer and let the water drain out.
Spread the paste on a wire mesh patting gently to get a
uniform layer.Cover with a newspaper and gently pat it
dry.Let it dry under sun for e few days. Your recycled
paper is ready. You can also add some colour and flower
petals to the pulp before spreading and drying to get
different kinds of recycled paper.
METHOD OF VERMICOMPOSTING
Dig a pit about 1 meter in depth. Spread a layer of sand at
the bottom. Throw in biodegradable wastes such as plant
wastes, paper and coffee and tea remains into it. Sprinkle
some water and place a few red worms in it. Cover loosely
with grass.
The red worms eat the wastes and convert it into compost.
Avoid putting wastes that may contain salt, pickles, oil
vinegar , meat and milk preparations as food for your red
worms, else the disease causing small organisms start
growing in the pit.
Gently turn over the top layers of the pit every 3-4 days.
After about 3-4 weeks the contents of the pit will be
completely changed into excellent compost.
Now put some waste in the corner of the pit so that most
of the red worms shift to this corner.
CLASSIFICATION OF WASTE
Waste can be classified into two types- biodegradable
and non-biodegradable.
a) BIODEGRADABLE WASTES- Plants waste such as fruit
and vegetable peels, leaves egg shells, paper (paper is
made from plants) and animal wastes like bones and
meat can be decomposed and mixed with the soil. These
are known as biodegradable wastes.
Biodegradable waste decomposes very quickly.
b) NON BIODEGRADABLE WASTES-Non biodegradable
wastes cannot be decomposed or take a very long time
to decompose. It includes plastic bags, packaging
material, glass bottles, metal containers like cans etc.
•
RECYCLING BIODEGRADABLE WASTES
COMPOST-The nutrients present in biodegradable wastes
like fruit and vegetable peels, leaves and farm wastes can
be recycled back into the soil by allowing the wastes to
decompose in a compost pit.
The bacteria and fungi that are present in the soil
decompose the wastes and restore the nutrients to yield
manure or compost. This method is called composting.
•
The manure thus obtained is rich in nutrients.
•
Composting is clean , cheap, safe and it
considerably reduces the amount of garbage to be
disposed.
*Take out the compost from the rest of the pit and dry
it in the sun. This can be used as manure in the garden.
Red worms do not have teeth but a structure called
gizzard which helps them in grinding their food.
Powdered egg shells or sea shells could be mixed with
the wastes which would help red worms in grinding
their food.
*This method works in warm and humid conditions as
red worms reproduce the best under such conditions
and their number can double in a month. Red worms
can't survive in very hot or very cold conditions.
CHAPTER- NUTRITION IN ANIMALS
THE MOUTH
THE FOOD PIPE- OESOPHAGUS
DIGESTION IN STOMACH
•
•
•
•
Saliva is a digestive juice that contains an
enzyme called amylase.
Tongue is a muscular organ that pusges the
food towards mouth, helps to mix the food
with saliva.
The tongue has taste buds present on its
surface which help in distinguishing the
tastes- sour , salty, sweet and bitter.
•
•
•
After the food is swallowed, it slides down
the pharynx into the esophagus (food pipe).
The esophagus leads from your mouth to the
stomach.
It is made of muscles which gently push the
food down to your stomach in a wave like
action called PERISTALSIS.
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DIGESTION IN THE SMALL INTESTINE
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The mucous protects the lining of the
stomach, the acid kills many bacteria that
enter along with the food and makes the
medium in the stomach acidic helping the
digestive juices to act.
The digestive juices break down the
proteins into simpler substances.
The stomach is thick walled, flattened U
shaped and the widest part of alimentary
canal.
It receives food from the food pipe at one
pipe and opens in small intestine at the
other end.
The inner lining of stomach secretes
mucous, hydrochloric acid and digestive
juices.
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It is highly coiled and is about 7.5m long.
Receives the secretions from the liver and the
pancreas .The wall of small intestine also
secretes juices.
The liver , the largest gland in the body secretes
bile juice which helps in the digestion of fats and
is stored in a sac called GALL BLADDER.
The pancreatic juice acts on carbohydrates , fats
and proteins and changes into simpler forms.
The intestinal juice completes the digestion of all
components of food.
The carbohydrates get broken down into simple
sugars such as glucose , fats into fatty acids and
glycerol and proteins into amino acids
ABSORPTION IN THE SMALL INTESTINE
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The digested food is then absorbed by small
intestine through thousands of small finger like
projections in the inner walls of small intestine
known as VILLI.
The villi increase the surface area of
absorbtion of digested food.
Each villus has a network of fine blood
capillaries close to the surface.
The food absorbed on the surface of villus
passes into the blood in the capillaries.
The food absorbed into the blood is
transported to different parts of the body
where it is used to provide energy and
materials for growth and repair of body tissues.
This is called assimilation.
LARGE INTESTINE
RUMINANTS
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The large intestine is widerand shorter
than small intestine about 1.5m long.
Its function is to absorb water and some
salts from the undigested food.
The waste food which is now almost solid is
stored in the last part of large intestine
called rectum and passed out of the body
through the anus .This is called egestion.
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Ruminants are plant or grass eating animals that
digest their food in two steps.For ex. Cows,
goats, sheep and bison
The grass is rich in cellulose and many animals
including humans can’t digest cellulose.
Food that is swallowed goes into the first
chamber called the RUMEN where it is partially
digested into cud.
It then goes to the second chamber from where
it is returned to the mouth for chewing.This
process is called RUMINATION and the animals
are as ruminants.
Ruminants have large sac like structure
called rumen between esophagus and small
intestine.
The cellulose of the food is digested here by
the action of bacteria not bacteria not present
in humans.
FEEDING AND DIGESTION IN
AMOEBA
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Amoeba has a cell membrane, a rounded
nucleus and many small vacuoles in its
cytoplasm.
It pushes out one or more finger like
projections called pseudopodia or false
feet formovement and capture of food.
On sensing food it pushes the pseudopodia
around the particle and engulfs it and the
food becomes trapped in a food vacuole.
Digestive juices are secreted into the food
vacuole and food is broken down into
simpler substances.
The undigested food is expelled out by the
vacuole.
MILK TEETH AND PERMANENT TEETH
* The deciduous (also called primary or milk) teeth is
the first ones to appear and they are fully formed by
age of 3. The complete deciduous (because they fall
like leaves of deciduous tree) teeth is 20. At age of 6
the first permanent teeth appear by displacing their
predecessors.
* The complete permanent teeth is 32.Permanent
teeth are stronger than the milk teeth. Wisdom tooth
appears between ages of 17-21, although not
everyone gets it. They are called wisdom teeth
because they appear when we grow older and
supposedly wiser.
TYPES OF TEETH
The Incisors (8 incisors are the very front human
teeth) are the teeth in the very front. They're the
sharpest teeth, built to cut food and shaped to
shovel the food inward.
The Canine (4 canine teeth) teeth are in the
corners of your mouth. Because they're meant
for grasping and tearing food, they have very
long roots.
HUMAN TEETH
•
The human tooth has two primary components:the
crown and root. The crown is the portion of the
tooth that projects above the gums while the root
is that portion that anchors the tooth to the bone.
The enamel covers the crown of the teeth and is
the hardest known substance in the human body.
STEPS INVOLVED IN NUTRITION
The various processes involved in nutrition, in
animals that take solid food are as follows:
1 Ingestion: The process of taking in food
through the mouth is known as ingestion.
2 Digestion: It is the process of breaking
down food- physically and chemically – into
simple and soluble form.
3 Absorption: The process of absorption
takes place in the small intestine. Here, the
digested food is absorbed in the blood
through the villi, which are sac-like
structures.
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INTRODUCTION
Animal nutrition includes nutrient requirement,
mode of intake and its utilization in the body.
The components of food are complex
substances which need to be broken down into
simpler substances.
The breakdown of complex components of food
into simpler substances is called digestion.
HUMAN DIGESTIVE SYSTEM
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The alimentary canal of digestive tract is divided
into various compartments 1) Buccal cavity 2)
food pipe or oesophagus 3) stomach 4) small
intestine 5) large intestine ending in rectum and
6) anus
The inner wall of stomach and small intestine
and various glands associated with the canal
such as salivary glands, liver, gall bladder and
pancreas are the organs that secrete digestive
juices that help convert complex substances in
food into simpler substances.
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TYPES OF TEETH
Premolars (8 premolars) are located just behind
your Canine teeth. Premolars have a more flat
chewing surface because they're meant for
crushing food.
The Molars (12 molars are the back human
teeth) are the last teeth towards the back of your
mouth. Molars are much bigger than the
Premolars and have bigger, flatter chewing
surfaces because their job is to chew and grind the
food into smaller pieces.
.DIFFERENT WAYS OF TAKING FOOD
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Bees and humming birds suck the nectar
of plants
Infants of human and many other animals
feed on mother’s milk.
Snakes like python swallow the animals
they prey upon
Some aquatic animals filter the food
particles floating nearby and feed upon
them.
Digestive juices are also secreted by the inner
walls of the stomach and small intestine.
THE MOUTH
• The process of taking in food is called
ingestion.
• The food is taken in is chewed and broken into
smaller pieces mechanically with the help of
teeth present in the mouth. The process of
breaking down the food physically is called
mastication.
• The saliva in the mouth secreted by salivary
glands helps to breakdown starch of the food
into sugars
CHAPTER- NUTRITION IN PLANTS
OTHER MODES OF NUTRITION
Depending on the mode of nutrition of
heterotrophs, all the heterotrophic plants can be
divided into:
a) PARASITIC PLANTS
• A parasitic plant is the one that derives
some or all of its nutrition from another
plant.
• The plant from which it obtains nutrition is
called the host.
• Since they deprive the host of its valuable
nutrients, it is called a parasite.
• For ex Cuscuta or Amarbel a plant parasite
and lice, leeches and mosquitoes (which
suck our blood) are also parasites.
SAPROTROPHS
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Saprotrophs are organisms like fungi and
bacteria that grow and feed on dead plants
or animals.
They do not have chlorophyll, hence can’t
perform photosynthesis. Because of the lack
of chlorophyll, these organisms can either
be colorless or can come in variety of colors.
They secrete digestive juices on dead and
decaying matter and convert it into a
solution and then absorb the nutrients from
this solution.
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INSECTIVOROUS PLANTS
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In some places, where soil is deficient in
nutrients especially in nitrogen, the plants
feed on insects to obtain nutrition. Such
plants are called as insectivorous plants.
Some common examples of insectivorous
plants (carnivorous plants) are: Pitcher
plant, Venus fly trap ad Bladderwort.
Insectivorous plants feed on insects to
obtain the nitrogen compounds needed for
their growth, hence are “partial
heterotrophs” as they get some food by
photosynthesis and some by eating insects.
FUNGI CAN BE USEFUL AS WELL AS
HARMFUL
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SYMBIOTIC PLANTS
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Some organisms live together and share
shelter and nutrients. This relationship is
called symbiotic relationship.
For ex. In lichens, a chlorophyll containing
partner, which is an ‘alga’ and a non-green
plant ‘fungus’ (Saprotrophs) live together.
This fungus provides shelter, water and
minerals to the alga and alga provides food
which it prepares by photosynthesis
Another example of symbiotic relationship is
provided by Rhizobium bacteria and
leguminous plants.
For ex. Fungi such as mushrooms and
yeast are useful as mushroom can be eaten
as vegetable whereas yeast is used to
produce alcohol.
Some fungi are also used for making
medicines. For ex. Penicillium fungus is
used in making antibiotic called penicillin.
Fungi can also cause diseases in plants and
human beings. The skin disease (called
ringworm) in humans is cause by fungus.
NITROGEN FIXATION BY RHIZOBIUM
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Crops require good supply of nitrogen in the
soil which after a harvest become deficient in
nitrogen.
Nitrogen is abundant in the atmosphere , but
the plants cannot take it directly from the
atmosphere.
Plants used nitrogen in soluble form so the
bacterium Rhizobium can take atmospheric
nitrogen and convert it into a soluble form.
Rhizobium , which cannot make its own food,
gets food and shelter from the leguminous
plants like it lives in the roots of gram, peas
moong etc.
NUTRIENTS- Components of food like
carbohydrates, proteins, fats, vitamins
and minerals that are necessary for our
body are called nutrients.
NUTRITION -the process of taking in
food by an organism and its utilization
by body is called nutrition.
MODES OF NUTRITION IN PLANTS
•
The mode of nutrition in which organisms
make food themselves from simple
substances is called autotrophic nutrition.
Such plants are called autotrophs.
HETEROTROPHIC NUTRITION
• Those organisms which cannot make food
themselves by the process of photosynthesis
and take food from green plants or animals,
are called heterotrophs and their mode is
heterotrophic mode of nutrition.
PHOTOSYNTHESIS
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AUTOTROPHIC NUTRITION
A chemical reaction takes place in the
leaves of plants as these raw materials carbon dioxide and water react.
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Carbon dioxide from air is taken in
through the tiny pores called stomata
present on the surface of leaves.
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SECTION THORUGH LEAF
Each stomata are surrounded by two
crescent shaped guard cells.
The products of the reaction are glucose
and oxygen.
The carbohydrate ultimately gets
converted into starch and oxygen is
released.
LEAVES OF VARIOUS COLOURS
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The leaves having colors other than green
also have chlorophyll in them .Actually, the
large amount of red, violet, brown or other
pigments in such leaves masks the green
color of chlorophyll. So, photosynthesis also
takes place in leaves of othercolors such as
red, violet, brown, etc.
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PHOTOSYNTHESIS
Green plants have the unique ability of
trapping the solar energy and converting
it to chemical energy which is stored in
the food. This process is called
photosynthesis.
Green plants can make their own food
from raw materials like carbon dioxide
and water in the presence of chlorophyll
(a green pigment present in the leaves)
and sunlight.
Hence we can say that chlorophyll, sunlight,
carbon dioxide and water are necessary to carry
out photosynthesis.
The process of photosynthesis can be represented
by a word equation as follows:
Carbon dioxide+ Water
Glucose + Oxygen
(from air) (from soil)
(a carbohydrate) (Goes to air)
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Algae are a large group of simple, plantlike organisms that contain chlorophyll
and produce food by photosynthesis just
like plants.
Algae however differ from plants
because they do not have proper roots,
stems and leaves.
The green color of algae is due to the
presence of chlorophyll in them.
CHAPTER- THE LIVING ORGANISMS AND ITS SURROUNDINGSCLASS VI
HABITAT AND ADAPTATION
• Are suited to the place where they live. The body
features of all organisms.
• The sea and desert are very different surroundings
and different kinds of plants and animals are found
in these two regions.
• For ex. The body structure of a camel helps it to
survive in desert conditions like:
i) Camels have long legs which help to keep their
bodies away from the heat of the sand.
ii) They excrete small amount of urine, their dung is also
dry and they do not sweat.
iii) I t has padded hoofs to enable it to walk on sand.
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HABITAT AND ADAPTATION
All living beings, plants and animals are called
organisms.
The process of specific features or certain
habits of an organism which help it to survive in
its surroundings are called ADAPTATION.
All organisms need a place to live where they can get
plenty of food, shelter and protection from enemies
and adverse conditions. The area or surroundings in
which an organism lives is called its HABITAT.
FIXED – The flowers, leaves and roots of these plants
float on water but their stems remains fixed to a place.
The roots are poorly developed. For ex water lilly and
lotus.
The stem of lotus is very long, thin and has air canals
in it. The petals and leaves have a waxy coating on
them to prevent from rotting.
c) SUBMERGED- Some plants like hydrilla, vallisnaria
remain submerged in water. Some of these plants have
narrow ribbon like leaves which can bend in water.
In some submerged plants the leaves are needle
shaped through which the water can easily flow
without damaging them.
HABITAT AND ADAPTATION
The body structure of a fish helps it to survive in sea
conditions like:
For ex. A fish has a streamlined body which helps it to cut
through water and move forward. It has fins to change its
direction. It has gills which help it to absorb the dissolved
oxygen in water.
A turtle has a soft body which can hide inside its
exoskeleton. It can live both on land and water.
It has a tall which helps it to swim.
COMPONENTS OF A HABITAT
A habitat has two components-Biotic and Abiotic.
a) BIOTIC COMPONENTS- plants and animals present
in a habitat.
b) ABIOTIC COMPONENTS- The non-living
components of a habitat lime the rocks, soil, air,
water, sunlight and temperature etc. are called
abiotic components of the habitat.
FEATURES OF AQUATIC HABITATS
Aquatic plants and animals are the ones which live in
water.OCEANS•
Some sea animals like squids and Octopus lives in the
depths of oceans and doesn’t have a streamlined shape.
They stay deeper in the ocean, near the seabed and
catch any prey that moves towards them. However when
they move in water they make their body streamlined.
• These use the oxygen dissolved in water through their
gills. Some animals like dolphins and whales that do not
have gills. They breathe in air through nostrils or
BLOWHOLES that are located on the upper parts of their
heads.
SOME AQUATIC HABITATS
ii) PONDS AND LAKES
In terrestrial plants, roots normally play a very
important role in the absorption of nutrients and
water from the soil.
However In aquatic plants, roots are much reduced in
size and their main function is to hold the plant in
place.
The stems of these plants are long, hollow and light.
FLOATING- These do not have well developed roots
and float with the current of water. Their flowers and
leaves remain above water. For ex. Duckweed.
i)
DESERTSThere are desert animals like rats and snakes ,which do
not have long legs like camel and to stay away from the
heat they stay in burrows during day and come out in
night. Their eyes are also adapted to see at night.
Desert plants like cactus lose very little water through
transpiration. The leaves in these plants are either absent,
very small, or they are present in the shape of spines
which help in reducing transpiration.
The leaf-like structure in cactus is its stem which helps in
carrying out PHOTOSYNTHESIS.
The stem is also covered with a thick waxy layer, which
helps to retain water
Most desert plants have roots that go very deep in the soil
for absorbing water.
MOUNTAIN REGIONS
The trees in mountain regions are normally cone
shaped and have sloping branches.
The leaves of some trees are needle like which helps
the rainwater and snow to slide off easily.
Animals like YAKS,have long hair to keep them
warm.
Snow leopard has thick fur on its body including feet
and toes which protects them from cold when they
walk on snow.
The mountain goat has strong hooves for running up
the rocky slopes of the mountains.
iii) GRASSLANDS
Lions have long claws in the front of their legs that
can be withdrawn inside the toes. Its light brown
colour helps it to hide in dry grasslands when it
hunts for PREY(animals to eat).
The eyes in the front of the face allow it to have a
correct idea about the location of its prey.
A deer is another animal that lives on forests a nd
grasslands and has strong teeth for chewing hard
plant stems of forest.
A deer has long ears to hear the movements of
predators(the animals which hunts other animals
for food).
The eyes of deer are on its side of its head which
allow it to look in all directions for danger.
LIVING BEINGS AND THEIR CHARACTERISTICS
*Some animals may have different mechanism for the
exchange of gases , which is a part of respiration
process.
For ex. Earthworms breathe through their skin.
Fishes have gills to use oxygen dissolvedin water.
*Exchange of gases in plants mainly takes place through
their leaves that have tiny pores in them and use oxygen
and give out carbon dioxide to the air.
*Plants produce their food only during daytime whereas
respiration takes place day and night.
*The amount of oxygen released in the process of food
preparation by plants is much more than the oxygen
they use in respiration.
ADAPTATION AND ACCLIMATISATION
If we go to high mountains, we feel breathlessness for
some time due to lack of oxygen in the air and soon our
body adjusts itself and we become normal.
These small and temporary changes in the body which
make an organism better suited to its changed
surrounding are called ACCILIMATISATION which are
different from ADAPTATION.
All living beings show response to stimuli
•
The change in the environment of an organism
is called STIMULUS and the reaction of that
organism to the stimulus is called RESPONSE.
For ex. If we accidently touch a very hot object, our hand
is withdrawn immediately .Here the hotness is the
stimulus and our action is the response.
• Many plants such as sunflower bends towards
sunlight.
• Some flowers bloom only at night.
• Some plants like mimosa leaves close or fold
when someone touches it.
• These are all responses of plants to external
conditions.
LIVING BEINGS AND THEIR CHARACTERISTICS
*All living things need food.
*All living things show growth.
*All livings respire- Respiration is the process through
which the body obtains energy from the food it takes.
The two main processes of respiration are:
i) EXTERNAL RESPIRATION or BREATHING- taking in
air rich in oxygen(inhalation) and giving out air rich in
carbon dioxide(exhalation).
ii) INTERNAL RESPIRATION or CELLULAR
RESPIRATION- Using oxygen to break down food to
release energy. It occurs in body cells.
In respiration, glucose molecules react with oxygen
and break down into carbon dioxide and water to
release energy.
C6H12O6+6O2
6CO2 + 6H2O+Energy
All living beings excrete- The throwing away of
unwanted or harmful wastes products from the body
is called excretion.
f) All living beings reproduce- Some animals like fish,
birds, snakes etc. lays eggs. These are also called as
Oviparous animals.
•
Some give birth to their young ones like
human beings , cat, dogs etc. These are also
called as Viviparous animals.
• Plants reproduce by different methods ,either
through seeds or through parts other than
seeds.
• VEGETATIVE PROPAGATION- It is a type of
reproduction in which new plants are
produced from the vegetative parts of a plant
like roots, stem, buds and leaves.
CHEMISTRY
Process to obtain wool from sheep: Steps given
below are followed to obtain wool from sheep or other
wool bearing animals
Step 1 – Shearing - The fleece (hair) of sheep is shaved
off along with a thin layer of skin. In olden days this was
done using pair of metal blades. But now-a-days machine
is used to cut off the fleece. This is similar to shaving of
beards or hair. This process is called shearing.
Shearing is done generally in summer so that sheep could
get new hair by winter to get protection against cold.
Step -2 – Scouring – Fleece, after shearing, is washed
properly to remove dirt and grease. The washing of fleece;
after shearing; is called scouring.
Step- 3 – Sorting – After scouring, fleece are sorted
according to texture. This process is called sorting.
Types of Silk: Different types of silk worm produce
different types of silk; in terms of luster and texture. For
example; tassar silk, mooga silk, kosa silk, etc. are
produced by different types of silk moth. Mulberry silk is
the most common silk moth.
Rearing of silkworm: Rearing of silkworm is known as
SERICULTURE. Silkworms are reared on mulberry leaves
as they feed on mulberry leaves.
Life cycle of silkworm:
Female silk moth → Lays eggs → After about 14 days
eggs are hatched into larva → Grown into Pupa →Weave
a net and enclosed itself → Produce liquid protein from its
salivary glands moving it’s head in the shape of ‘8’ forming
cocoon→ Live in the cocoon for some time → After
coming out of cocoon grows into silk moth
.
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Nylon is the first fully synthetic fibre made
by man without using any natural raw
materials (pNylon is the first fully synthetic
fibre made by man without using any
natural raw materials (plants and animals).
• It was prepared from coal, water and air.
• Nylon polymer is a polyamide - a polymer
that is made up of 2 different monomers, a
diamine and a dicarboxylic acid, combined
alternately to form long chains.
• Nylon fibres are very strong, fairly elastic ,
lightweight and lusturous and easy to wash.
lants and animals).
•
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Rayon is a semi synthetic fibre because
although it is obtained from a natural
resource called wood pulp(polymeRayon is
a semi synthetic fibre because although it is
obtainedRayon is a semi synthetic fibre
because although it is obtained from a
natural resource called wood pulp(polymer
cellulose), yet it is a man made fibre
because it is obtained by chemical
treatment of wood pulp in factories.
Rayon is chemically identical to cotton but
it has shine like silk. as artificial silk.
Step – 4 – After sorting, fluffy fibers; called burr; are picked
out from hair. Burr is the fiber that gives wool.
Step 5 – Dying – After sorting and picking out of burrs,
these are dyed in desired colors.
Step 6 – Spinning – The fibers are then straightened,
combed and rolled into yarns.
Wool yarn is used in knitting sweaters and woolen cloths,
i.e. fabric
Silk moth to silk:
After they are laid by the silk moth; eggs are stored over a
clean cloth or paper strips. When larvae are hatched from
eggs, they are kept in clean bamboo trays with fresh
leaves of mulberry. Larvae feed on mulberry leaves for
about 20 to 25 days. After that, larvae move into tiny
chambers of bamboo in which they start spinning cocoon.
They do it by secreting liquid protein from their salivary
glands. Finally they enclose themselves in cocoon.
Cocoons get hardened because of exposure to air.
Obtaining of silk from cocoon:
First of all, cocoons are boiled and then silk fiber is
separated out; using machines. Machine unwinds the silk
thread from cocoons. The process by which silk fiber is
obtained is called REELING THE SILK.
Silk thread so obtained is woven into different types of
cloths, i.e. fiber.
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Polyester(poly+Polyester(poly+ester) is
another synthetic fibre which contain
many ester groups.
Esters are the organic chemical substances
which give fruits their sweet smell.
Terylene is a popular polyester fibre.
Most of the properties of polyester fibres
(like terylene)are similar to those of nylon.
Polyester fibres are , however stronger
than nylon fibres
Polyester fabric is strong ,wrinkle resistant
, easy to wash and dry.
ester) is another synthetic fibre which
FOOD
Food
Importance of food
• Food provides energy.
• Food is needed for growth.
• Food helps in maintaining good health.
• Food maintains body functions.
• Food is necessary to heal wounds.
Edible parts of the plant
a) Roots: carrot, turnip, radish and beetroot.
b) Stem: sugarcane, potato, ginger.
c) Leaves: sources of calcium. spinach, cabbage,
Amaranthus, curry and Onion leaves etc.
d) Flowers: pumpkin, banana, cauliflower.
e) Fruits: fleshy or dry e.g. mango, guava, orange,
apple, pear, grapes, banana , almonds, cashew nut
brinjal, tomato, lady's finger, beans, bottle guard,
snake gourd, bitter gourd .
Components of Food
Nutrients are nourishing components of food that
are required by our body.
Energy-giving food :They release energy and help in
body growth.: Carbohydrates and fats
Body-building food: Proteins they help in body
growth and repair of damaged parts of the body.
Protective food: Vitamins and minerals they protect
us from many dieases. They give us resistance
against disease causing germs.
1) Carbohydrates: sugar, starch and cellulose.
Sugar is sweet. Glucose is the instant sugar.
Fructose fruit sugar. Common sugar sucrose
Lactose milk sugar.
Starch in grains like rice, wheat, maize, tubers like
potatoes etc.
Cellulose cannot be digested by human beings
f) Seeds: Grains., pulses and oil seeds.
Grains include rice, wheat, jowar, maize, ragi etc.
Pulses include grams, peas, beans etc.
Oil seeds include groundnut, sesame, mustard,
coconut, sunflower seed etc.
Poultry farm is the place used to rear birds for their
eggs and meat.
Dairy farm is the place where buffaloes, goats,
cows, sheep, pigs etc are kept in shed for rearing.
We rear animals for their milk and meat. Milk is
also used to prepare dairy products.
Aquaculture includes rearing of fish, crabs, lobsters
etc. Fish provide their meat for us. Fish can be
marine or freshwater fish.
. Animals and their food:Based on food they eat
a) Herbivores: Animals which eat only plants(grasseating animals) e.g. Cow, sheep, goat, deer, buffalo.
2)Proteins: Proteins help in healing of wounds.
Proteins also help in repair of damaged parts in
the body.
3) Fats: Fats are energy-giving food. They provide
us with more energy
From Animal: milk, butter, ghee, cheese and meat.
From plants ( oils).Seeds like mustard, sesame,
groundnut, soyabean, coconut, sunflower,
safflower
4)Vitamins& minerals: Protect our body from
diseases. Green vegetables &leafy vegetables,
beans, pulses whole grains, unpolished rice .
5) Water: It protects us from dehydration, easy
passage of food. It dissolves many substances in it,
forms the liquid medium of blood ,acts as main
transport channel throughout the body.
.b) Carnivores: Animals which eat only small
animals (flesh-eating animals) e.g. Tiger, lion,
jackals, vultures etc.
c) Omnivores: Animals which eat both plants and
animals . e.g. Human being, bear, crow etc.
d) Decomposers: Organisms which feed on dead
plants, dead animals and rotten materials and
decompose for their food .Bacteria and Fungi
e)Scavengers: Organisms which feed on dead
animals . e.g. Vulture
6) Dietary fibres:(roughage) easy digestion of
food, they provide us bulkiness in the stomach.
Test to confirm the presence of
1)carbohydrate (starch)-Iodine Test (Blue black
colour confirms the presence)
2)Proteins-copper sulphate and caustic soda
(Violet colour confirms the presence)
3)Fats-An oily patch on the paper indicates the
presence of fat.
Deficiency Diseases:1)Protein Energy
Malnutrition (PEM)-Kwashiorkor and Marasmus
2) Iron deficiency: Anaemia.
3) Iodine deficiency: Goitre
4) Vitamin A: Night blindness
5)Vitamin B1: beriberi.
6) Vitamin C: scurvy
7) Vitamin D: rickets
Getting to know Plants
Based on the size, nature of the stem and the life
span, plants are classified into herbs, shrubs, trees,
creepers and climbers.
a) A herb: non-woody plant that has green and
tender stem with few branches on it &has a very
short life,. Mustard, Tulsi, Wheat, Gram
b)A shrub is taller than a herb and has stem
branching out at its base, bushy plant. The stems
are not hard but thick. Sunflower, Rose, Lime
c) A tree is a woody plant that has many branches
on a single stem. Mango , Neem , Peepal tree
d) Creepers are the plants with weak stems and
hence cannot stand straight.
Depending on the presence of flowers, a) Flowering
e.g. Mango, Papaya, Guava.
b) Non-floweringe.g. Fern, Moss.
Depending on the way they obtain food
a) Autotrophs . e.g. Most of the green plants.
b)Heterotrophs e.g. Insectivorous plants
Parts of a plant:Root: Underground and look
brown in colour. The tiny thread-like structures
over the roots are the root hairs. The tip of the
root is covered by root cap which is preventive in
function. Root and the root hairs form the root
system
Modifications of roots.
1.Storage roots: Carrot, turnip, radish etc
2.Respiratory : pneumatphores(Mangrooves)
3.Parasitic roots . e.g.Cuscuta.
4.Climbing roots . e.g. Money plant, betel.
5.Reproductive roots
6.Prop roots :. Banyan tree
Types of rootsRoots are of two types - tap root
and fibrous roots.
2)Stem :seen above the ground. It bears the
leaves, flowers and fruits of a plant.
Modifications of stem.
1.Storage of food: are tubers (e.g. Potato),
rhizome (e.g.Ginger) and bulb (e.g.Onion).
Body Movement
Locomotion is brought about by the combination of
muscular and skeletal system. The bending and
movement of the skeleton is brought about by
special structures called as joints.
Joints Joint is a point at which two separate bones
meet. Joints are held at position by strong cords
called as ligaments.
a) Fixed or immovable joints :sutures between the
bones of the cranium,ribs in the breast bone, bones
of the hip girdle.
b) Slightly movable joints :joints of the lower jaw
c) Freely movable.1)Ball and socket joint: Shoulder
joints and hip joints.
2)Pivot joint: joint which joins the neck to the head.
3)Hinge joint: the elbow joint and the knee joint.
4)Gliding joints: ankles,wrist & between vertebrae.
Movement in bones:Joints along with muscles can
bring about movement in bones.
Skeleton:is an internal framework of all the bones
and cartilage in the human body. Bone is a type of
fibrous connective tissue. Bones also anchor the
muscles. Cartilage is a soft elastic tissue that
covers the bones at the region of the joints.
Types of bones
a)Round and long: in limbs.
b)Ring like bones with outgrowths: vertebrae Flat
and strong: skull
c)Girdles: shoulder region and pelvic region.
Parts of skeleton
a)Axial skeleton includes the skull, vertebral
column and the rib cage.
b)Appendicular skeleton includes shoulder bone,
pelvic bone, arm bone, and the leg bone.
2.Photosynthesis: In some desert plants,
3.Protective structures: rose, Supportive
structures: In climbing plants,
4.Storage of water: cactus and jade
3) Leaves have chloroplasts which have
chlorophyll in them.
Parts of leaf: leaf base., petiole, lamina.,mid-vein.
veinlets. Veins help in transportation of food and
water. parallel venation and reticulate venation
Types of leaves1):Simple 2)Compound
Arrangement of leaves. Arrangement can be
alternate,opposite, whorl etc.
Functions of leaf 1)photosynthesis 2)transpiration
Modifications of leaf a) tendrils b) store food
c)insectivorous plants,
4)Flower:reproductive structure
5)Fruit: Fruit is basically the fertilised ovary.
1.Gait of earthworms:Earthworm is a small
annelidan .Possesses setae which help in their
movement. Earthworms move forward by
repeated contractions and relaxations of their
muscles in the skin.A slimy substance secreted
by the earthworm helps in its movement.
2.Gait of cockroaches:Cockroach is an
arthropod with six jointed legs which help it to
walk, and two pairs of wings help it to fly.
3.Gait of snails:Snail is a small molluscan with
thick exoskeleton.Single muscular foot for
locomotion.
4)Gait of fish:Fish vertebrate with vertebral
column in its body. possess a streamlined
body, fins,.tail flaps which help them swim
5)Gait of snakes: vertebrates with vertebral
column. Have long back bone & many
interconnected muscles that help them to
slither.
6)Gait of birds: arboreal in habit. They fly in the
air(wings). They can also walk. Birds have light
and hollow bones.