How do plants and animals help each other in the exchange of gases in the atmosphere?
Animals breaths out carbon dioxide. This carbon dioxide can be used by plants to prepare their food, this process is called photosynthesis which makes the balance on earth. Animals and plants by exchange of gases help each other to survive.
How will you prove that air supports burning?
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?
What is the composition of air?
Why does a lump of cotton wool shrink in water?
The component of air used by green plants to make their food, is ___________.
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.
Is it possible for you to recognize the leaves without seeing them? How?
Name two flowers, each with joined and separated sepals.
Match the items in Column I with one or more items of Column II.
Column I Column II
Upper jaw have fins on the body
Fish has an outer skeleton
Ribs can fly in the air
Snail is an immovable joint
Cockroach protect the heart
shows very slow movement
have a streamlined body
Which of the following plants have you seen? of those that you have seen, which one have flowers?
Grass, maize, wheat, chilli, tomato, tulsi, pipal, shisham, banyan, mango, jamun, guava, pomegranate, papaya, banana, lemon, sugarcane, potato, groundnut
Would the bulb glow in the circuit shown in Fig. 12.15?
To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Given below are the names of some objects and materials:
Water, basket ball, orange, sugar, globe, apple and earthen pitcher Group them as:
(a) Round shaped and other shapes
(b) Eatables and non eatables
What is the function of a stem in a plant?
Name two foods each rich in:
(a) Fats
(b) Starch
(c) Dietary fibre
(d) Protein
List all items known to you that float on water. Check and see if they will float on an oil or kerosene.