True or false?
(a) A mixture of milk and water can be separated by filtration.
(b) A mixture of powdered salt and sugar can be separated by the process of winnowing. (c) Separation of sugar from tea can be done with filtration.
(d) Grain and husk can be separated with the process of decantation.
(a) False
No, both are miscible components and make a homogeneous mixture. So we cannot separate them by filtration.
(b) False
We cannot separate them by winnowing method because in powdered form they both will make a homogenous mixture.
(c) True
Yes, it is so because by filtration the larger particles of sugar can be separated whereas the solution of tea can pass through it easily.
(d) False
No, because decantation method is used for two immiscible components. This can be done by winnowing.
Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it?
Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving
sugar? In which case would it be possible to dissolve more sugar?
How will you separate sand and water from their mixture?
How would you obtain clear water from a sample of muddy water?
Fill up the blanks
(a) The method of separating seeds of paddy from its stalks is called ___________.
(b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of ___________.
(c) Salt is obtained from seawater by the process of ___________.
(d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called ___________.
What is sieving? Where is it used?
How will you separate husk or dirt particles from a given sample of pulses before cooking.
What is winnowing? Where is it used?
Why do we need to separate different components of a mixture? Give two examples.
(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.
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.
What is a habitat?
In which part of a flower, you are likely to find the ovary?
(a) Collect pieces of different kinds of paper. Find out which of these can be recycled.
(b) With the help of a lens look at the pieces of paper you collected for the above question. Do you see any difference in the material of recycled paper and a
new sheet of paper ?
Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute
State whether the following statements are true or false:
a) Yarn is made from fibres.
b) Spinning is a process of making fibres.
c) Jute is the outer covering of coconut.
d) The process of removing seed from cotton is called ginning.
e) Weaving of yarn makes a piece of fabric.
f) Silk fibre is obtained from the stem of a plant.
g) Polyester is a natural fibre.
From which parts of the plant cotton and jute are obtained?
What is the function of a stem in a plant?
Fill in the blanks.
(a) ______________ is caused by deficiency of Vitamin D.
(b) Deficiency of ______________ causes a disease known as beri-beri.
(c) Deficiency of Vitamin C causes a disease known as ______________.
(d) Night blindness is caused due to deficiency of ____________ in our food.
Answer the following:
(a) What is a ball and socket joint?
(b) Which of the skull bones are movable?
(c) Why can our elbow not move backwards?
Explain the process of making yarn from fibre.
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 .