A. Kidneys removes extra salts and water from the blood
B. The urine is stored in Urinary bladder
C. Through urethra urine is excreted out of the body.
D. Ureter transfer urine from the kidneys to the urinary bladder.

Cell Organelles	Main Functions
Cell wall	Surrounds and protects the cell. Make the cell stiff and strong.
Cell membrane	Holds and protects the cell. Controls the movement of materials in and out of the cell.
Cytoplasm	A watery gel - like material in which cell parts move.
Mitochondria	Produce and supply most of the energy for the cell.
Chloroplasts	Capture the energy from sunlight and use it to produce food for the cell by photosynthesis.

The expansion of substance on heating is called, the thermal expansion of that substance 
(i) Gaps are left in between rails while laying railway track :
So that there is enough margin for the tracks to expand and contract due to the temperature changes. If that gap is not left then the tracks might have enormous stress in them while expanding due to heat, which can damage them.
(ii) Gaps are left in between two joints of a concrete bridge:
Thermal expansion takes place due to the increase in the kinetic energy of the constituent molecules as they are heated. Thermal expansion is the reason we leave some gaps between section of h concrete bridge.

(i) Computers are used in various fields.
(ii) In textile shop it is used for billing.
(iii) Computers are used to control large and small machines.
(iv) Computers are most important educational tools for teachers and learners.
(v) In Railways it is useful to book tickets and for other purposes.
(vi) It is also used in banks, ATM's, Post offices and in many places.
(vii) We can save many data and convert it into information.

S.no	Property	deficiency disease
1	vitamin A	Night blindness
2	vitamin B	Beri beri
3	vitamin C	Scurvy
4	vitamin D	Rickets
5	vitamin E	Nervous weakness, dimming of eyesight
6	vitamin K	Weakness of the bones, teeth etc.

FUNCTIONS OF THE ROOT:
i) The root fixes the plant to the soil.
ii) Absorbs water and minerals from the soil.
iii) Stores food in some plants like Carrot and beetroot
FUNCTIONS OF THE STEM:
i) The stem supports the branches, leaves, flowers and fruits.
ii) Transports Water and minerals from roots to upper aerial plant parts.
iii) Transports the prepared food from leaves to other parts through stem.
iv) Stores food as in the case of sugarcane

Linear motion - A coconut falling from a tree
Curvilinear motion - A car driving around a curve
Self rotatory motion - Motion of the wheel in a cart
Circular motion - Athlete running around a track
Oscillatory motion - Swinging of a pendulum
Irregular motion - Movement of people in a bazaar

When there is a change of position of an object with respect to time then it is called motion.
Types of motion:
a) Based on path:
i) Linear motion - a person walking on a straight path
ii) Curvilinear motion - throwing ball
iii) Circular motion - swirling stone tied to the rope
iv) Rotatory motion - a rotating top
v) Oscillatory motion - pendulum of clock
vi) Zig zag (or) Irregular motion - the motion of a bee
b) Based on duration:
i) period motion - movement of hour hand of a clock
ii) Non-periodic  - motion flapping of a flag in wind
c) Based on speed:
9) Uniform motion -  motion of a train at a constant speed
ii) Non-uniform motion - a vehicle moves in different speed

Property	Definition	Basic unit	Instrument used for measuring
Length	The distance between one end and the other desired end.	Metre	Ruler, Measuring tape.
Mass	The amount of matter in an object	Kilogram	Beam balance,Electronic balance
Volume	The amount of space a substance occupies	cubic metre (or) litre	measuring jar, Pipetter buret etc
Time	Interval between two events	Second	Stop clock Electronic clock; etc

Distance travelled (d) = 400 km
Time taken (t) = 5 hour
Average Speed (s) = \(\frac{d}{t}=\frac{400}{5}=80\) 
Average Speed = 80 kmph (or) Km/hr.

Fire extinguishers throw a stream of carbon-, di-oxide while putting - off fire. Carbon-di-oxide covers the fire and cut-off the supply of fresh air to the burning things and stop burning.

a) melting of wax and
d) Solidification of the molten wax can be reversed.
Burning of candle is a physical / reversible change. That is,
\(\text { Solid wax } \underset{\text { Cooling }}{\stackrel{\text { Heating }}{\rightleftarrows}} \text { molten wax }\)

(i) Yes, the bulb will glow.
(ii)  A piece of zinc metal (such as a galvanized nail) and a piece of copper are inserted into a lemon and connected by LED bulb.
(iii) The zinc and copper are electrds and the juice (acetic acid) is a electrolyte.
(iv) Power generated by reaction of the metals in acetic acid.

(i) Using beakers, the mustard oil is separated by the process of decantation, because oil being lighter than water, floats on water.
(ii) Next filtration is using a funnel and filter paper and thus water gets separated from chalk powder and coins.
(iii) By hand-picking method, the coins are separated frorn chalk powder.

(i) The rib cage is made up of 12 pairs of curved, flat rib bones.
(ii) It protects the delicate vital organs such as heart and lungs.

SI.No.	Prokaryotic cell	Eukaryotic cell
1.	It's diameter ranges from 1 to 2 micron	It's diameter ranges from 10 to 100 micron
2.	Absence of membrane bound organelles	Presence of membrane bound organelles
3.	Nucleus consisting of no nuclear membrane	True nucleus consisting of nuclear membrane
4.	Absence of nucleoli	Presence of nucleoli

They are exposed to harsh weather conditions, dust, pollution, heat and cold. So, they can have an adverse effect on their health. Hence, they weak a mask on duty.

No. Deforestation can be an undesirable change. That is, Deforestation is harmful to our environment and not desired by us.

The molecules in the solid move faster and vibrate when heating. Spread apart and occupy more space. So solid expands when heated.

Adaptations seen in different types of vertebrates are

SI.NO	NAME OFTHEANIMAL	HABITAT
1.	Fish	Lake, Sea
2.	Lizard	Land
3.	Birds	Land
4.	Camel	Desert
5.	Polar Bear	Polar region
6.	Penguin	Polar region
7.	Mountain Goat	Mountains
8.	Lion	Forest

Pure substances are mixed with harmful and unwanted substances. This process is called adulteration.

TAP ROOT SYSTEM	FIBROUS ROOT SYSTEM
(i) It consists of a single root called tap root and some smaller lateral roots arise from the tap root.	(i) It consists of a cluster of roots arising from the base of the stem.
(ii) They are seen in dicotyledonous plants.	(ii) It is generally seen in monocotyledonous plants.
(iii) Ex: Bean, Mango	(iii) Ex: Grass, paddy, maize

Digestion and absorption of food done by digestive system.

The skeletal system consists of bones, cartilages and joints. It provides a framework for the body.

Plant cell,Animal cell and most of fungi.

(i) Cell membrane
(ii) Cytoplasm
(iii) Nuclecus are the essential components of a cell.

We have eukaryotic cells.

If we remove the fish from the aquarium and keep it in a dark place with green plants,
(i) they can't have sunlight and
(ii) have no CO₂ from the water produced by fish as they breathe.
(iii) Simply say, there is no possibility for photosynthesis to make their food.

If we remove plants from the aquarium
(i) All types of wastes created by aquatic animals, excess food and decaying materials level will increase in water.
(ii) The dissolved oxygen level in water will decrease.
(iii) Algae will grow due to excess nutrients and light in aquariums.
(iv) Some types of fish even breed and lay eggs on the leaves of ths plants. This will affect.

On strong heating, cane sugar chars to almost pure carbon giving the smell of 'Burnt sugar'.
(i) Initial change - Physical change - melting
(ii) Final change - Chemical change - charring

Yes, we can make a candle doll from candle wax. It is a kind of physical change.

Plants decaying is a chemical change.

Simple circuit is there in a torch light.

K₁, K₂  should be closed.

(i) The Water heater
(ii) Iron box
(iii) Electric kettle etc.

The birds catch their pray with their beaks and with a pair of claved feet

We have to separate mixture,
(i) to remoe impurities
(ii) to separate useful components
(iii) to get a highty pure form substance

Husk or fine dust particles cdnbe separated from rice by the method 'winnowing"

The green leaves prepare food by the.process of photosynthesis.

The area where a particular organism actually lives is called its habitat.

S.No	Hardware	Software
1	The parts that are available in the computer that helps the software to work is a hardware.	The commands or programs that are used in computer are called software
2	The two types of hardware are  i) Input devices ii) Output devices	The two types of software are  (i) Operating Software (ii) Application Software

Charles Babbage and Augusta Ada Lovelace are the pioneers of computer.

We should not wash the fruits and vegetables after cutting because they lose some of their nutrients and thus their nutritional value gets reduced.

(a) Food items rich in fat - Ex: Butter, Ghee.
(b) vitamin deficiency diseases - Ex: Night blindness, Beri-beri

c. Flash card

1 millimetre < 1 centimetre < 1 Metre < 1 kilometre.