The component of air used by green plants to make their food, is ___________.
Carbon dioxide
Green plant use carbon dioxide to prepare food for their own, which they get from the environment. Human beings exhales carbon dioxide and which is then is used by plants.
How will you prove that air supports burning?
How do plants and animals help each other in the exchange of gases in the atmosphere?
List five activities that are possible due to the presence of air.
The layer of air around the earth is known as ___________.
How will you show that air is dissolved in water?
Why does a lump of cotton wool shrink in water?
What is the composition of air?
Which gas in the atmosphere is essential for respiration?
(a) Which kind of garbage is not converted into compost by the redworms?
(b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.
Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Do you find that all living beings need the same kind of food?
Name the major nutrients in our food.
Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute
Name five objects which can be made from wood.
Why do we need to separate different components of a mixture? Give two examples.
Correct the following statements and rewrite them in your notebook.
(a) Stem absorbs water and minerals from the soil.
(b) Leaves hold the plant upright.
(c) Roots conduct water to the leaves.
(d) The number of petals and sepals in a flower is always equal.
(e) If the sepals of a flower are joined together, its petals are also joined together.
(f) If the petals of a flower are joined together, then the pistil is joined to the petal.
Fill in the blanks:
(a) Joints of the bones help in the ——————— of the body.
(b) A combination of bones and cartilages forms the _______ of the body.
(c) The bones at the elbow are joined by a ______________________ joint.
(d) The contraction of the _____________ pulls the bones during movement.
Discuss :
(a) Is garbage disposal the responsibility only of the government?
(b) Is it possible to reduce the problems relating to disposal of garbage?
The height of a person is 1.65 m. Express it into cm and mm.
Explain the process of making yarn from fibre.
Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?
How are clouds formed?
Why do we need to separate different components of a mixture? Give two examples.
Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a
given material could be used for making many objects.
Objects Materials
Book Glass
Tumbler Wood
Chair Paper
Toy Leather
Shoes Plastics
It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.
What is the function of a stem in a plant?
Fill up the blanks
(a) The presence of specific features, which enable a plant or an animal to live in a particular habitat, is called .
(b) The habitats of the plants and animals that live on land are called habitat.
(c) The habitats of plants and animals that live in water are called habitat.
(d) Soil, water and air are the ———— factors of a habitat.
(e) Changes in our surroundings that make us respond to them, are called .