(i) A snakes head contains the eyes, nostrils, mouth brain and a special sensory structure.
(ii) Snakes are entirely covered with scales.

PURE SUBSTANCE	IMPURE SUBSTANCE
A pure substance is made up of only one kind of particulars.	An impure substance contains more than one kind of particulars.
The components are mixed chemically in a fixed ratio.	The components are mixed physically in any ratio.

The settling down of heavier component of a mixture when allowed to remain undisturbed for some time is called sedimentation.

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

A balanced diet is one which contains adequate amount of al the necessary nutrienrs required for healthy growth and activity.

Force is push or pull by an animate or inanimate agency.

Kilogram.

Beam balance (or) Electronic balance

i) Birds have streamlined body covered with feathers. This body shape provides minimum resistance to air.
ii) They have a pair of wings to fly in the air.
iii) They have hollow and light bones.

S.No.	Unicellular Organisms	Multicellular Organisms
1	They are made up of single cell.	They are organisms are made up of many cells.
2	The single cell of the organism can perform all the functions of life.	Division of labour exists among cells. Different cells are specialized to peform different functions.
3	These organisms are generally very small (microscopic) in size.	They are mostly large in size
4	They lack tissues, organs and organ systems.	They are composed of tissues, organs and organ system
5.	Growth occurs by an increase in the size of the cell. eg. Amoeba, Paramecium and Euglena.	Growth occurs by an increase in the number of cells by cell division. eg. Earthworms, Fish, Frogs, Lizard and human beings.

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

(i) Yes, a rubber ball can be called a solid because it doesn't flow away like liquids or gases.
(ii) But the rigidity of the rubber ball is less than the external force. So it changes its shape.

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

We know, 1km = 1000 m.
\(\therefore\)  43.65 km = 43.65 x 1000 m = 43650 m
1m = 100cm 
43650m = 100 x 43650
= 43,65,000 cm
43.65 km = 43,650 m
= 43,65,000 cm.

The comparison of an unknown quantity with some known quantity is known as measurement.

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.

(1) The camel has long legs which help it to keep its body away from the hot sand in the desert.
(2) It can store large amount of water in its body.
(3) it loses very little water from its body through excretion.
(4) A camel's hump has fat stored in it. It ups the stored fat when required.
(5) It has large and flat padded feet to walk easily on soft sand.
(6) It has long eye lashes and hairs to protect its eyes and ears from the blowing dust.
(7) It can keep its nostrils closed to avoid dust.

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

Method 1:
(i) Place a string along the curved line, Make sure that the stringcovers every bit of the curved line.
(ii) Mark the points where the curved line begins and ends on the string.
(iii) Now, stretch the string along the length of a meter scale and measure the distance between the two markings of the string.
(iv) This will give us the length of a curved line.
Method 2:
(i) Draw a curved line AB on a piece of paper.
(ii) Separate the legs of the divider by 0.5 cm or 1 cm using a ruler.
(iii) Place it on the curved line starting from one end. Mark the position of the other end. Move it along the line again and again cutting the line into number of segments of equal lengths. The remaining parts of the line can be measured using a scale.
(iv) Count the number of segments.
(v) Therefore, the length of the line = (number of segments x length of each segment) + length of the left over part.

Non contact force