Class 6 Science QA Set 1

Chapter 1 − Food: Where does it come from

 

Q.1. Do you find that all living beings need the same kind of food?

Ans. No. The food requirements of all living organisms vary. On the basis of food requirements, living organisms are grouped into three categories:

(i) Herbivores: These animals eat only plants or plant products. For example: Cow, elephant, rabbit, horse, etc.

(ii) Carnivores: These animals eat other animals. For example: Lion, tiger, lizard, etc.

(iii) Omnivores: These animals eat both plants and animals. For example: Dog, cat, crow, etc.

Q.2. Name five plants and their parts that we eat.

Ans.

Q.3. Match the items given in Column A with that in Column B.

Ans.

 

Q.4. Fill up the blanks with the words given:

herbivore, plant, milk, sugarcane, carnivore

(a) Tiger is a _________ because it eats only meat.

(b) Deer eats only plant products and so, is called _________.

(c) Parrot eats only _________ products.

(d) The _______that we drink, which comes from cows, buffaloes and goats is an animal product.

(e) We get sugar from _________ .

Ans.

(a) Tiger is a __carnivore__because it eats only meat.

(b) Deer eats only plant products and so, is called __herbivore__.

(c) Parrot eats only __plant__ products.

(d) The __milk__ that we drink, which comes from cows, buffaloes and goats is an animal product.

(e) We get sugar from __sugarcane__.

 

Chapter 2 – Components of Food

 

Q.1. Name the major nutrients in our food.

Ans: The major nutrients in our food are: Carbohydrates, proteins, fats, vitamins, and minerals.

Q.2. Name the following:

(a) The nutrients which mainly give energy to our body.

(b) The nutrients that are needed for the growth and maintenance of our body.

(c) A vitamin required for maintaining good eyesight.

(d) A mineral required for keeping our bones healthy.

Ans:

(a) Carbohydrates and fats

(b) Proteins and minerals

(c) Vitamin A

(d) Calcium

Q.3. Name two foods each rich in:

(a) Fats

(b) Starch

(c) Dietary fibre

(d) Protein

Ans:

(a) Groundnut and Butter

(b) Rice and Mango

(c) Potatoes and pulses

(d) Fish and Gram

Q.4. Tick (Ö) the statements that are correct.

(a) By eating rice alone, we can fulfil the nutritional requirement in our body. ( )

(b) Deficiency diseases can be prevented by eating a balanced diet. ( )

(c) A balanced diet for the body should contain a variety of food items. ( )

(d) Meat alone is sufficient to provide all nutrients to the body. ( )

Ans:

(a) By eating rice alone, we can fulfil the nutritional requirement in our body. (×)

(b) Deficiency diseases can be prevented by eating a balanced diet. (Ö)

(c) A balanced diet for the body should contain a variety of food items. (Ö)

(d) Meat alone is sufficient to provide all nutrients to the body. (×)

Q.5. Fill in the blanks:

(a) _________ is caused by the 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.

Ans:

(a) __Rickets__ is caused by the deficiency of vitamin D.

(b) Deficiency of _vitamin B₁_ causes a disease known as beri-beri.

(c) Deficiency of vitamin C causes a disease known as __scurvy__.

(d) Night blindness is caused due to deficiency of __vitamin A__ in our food.

 

Chapter 3 – Fibre to Fabric

 

Q.1. Classify the following fibres as natural or synthetic:

Nylon, wool, cotton, silk, polyester, jute

Ans. Fibres that are obtained from nature, i.e., from plants and animals are called natural fibres and those made by humans by chemical methods are known as synthetic fibres.

Wool and silk are obtained from animals and cotton and jute are obtained from plants. Hence, they are natural fibres. Nylon and polyester on the other hand are prepared artificially and are therefore synthetic fibres.

Q.2. State whether the following statements are ‘true’ or ‘false’:

a) Yarn is made from fibre.

b) Spinning is a process of making fibres.

c) Jute is an outer covering of coconut.

d) The process of removing seeds 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.

Ans.

a) Yarn is made from fibre. (True)

b) Spinning is a process of making fibres. (False)

c) Jute is an outer covering of coconut. (False)

d) The process of removing seeds from cotton is called ginning. (True)

e) Weaving of yarn makes a piece of fabric. (True)

f) Silk fibre is obtained from the stem of a plant. (False)

g) Polyester is a natural fibre. (False)

Q.3. Fill in the blanks:

(a) Plant fibres are obtained from ________ and ________.

(b) Animal fibres are ________ and ________.

Ans.

(a) Plant fibres are obtained from __fruits__ and __stems__.

(b) Animal fibres are __wool__ and __silk__.

Q.4. From which parts of the plant cotton and jute are obtained?

Ans. Cotton fibres are obtained from the fruit of cotton plants. The fruit of a cotton plant is known as cotton bolls. Jute fibres are obtained from the stem of jute plants.

Q.5. Name two items that are made from coconut fibre.

Ans. Two items that are made from coconut fibre are:

(i) Ropes

(ii) Baskets

Q.6. Explain the process of making yarn from fibre.

Ans. The process of making yarn from fibre is called spinning. The fibres are first drawn out from their source and then twisted into yarn. Two devices used in spinning are takli and charkha.

 

Chapter 4 – Sorting Materials into Groups

 

Q.1. Name five objects which can be made from wood.

Ans. Five objects that can be made from wood are:

(i) Table

(ii) Chair

(iii) Bed

(iv) Door

(v) Bullock cart

Q.2. Select those objects from the following which shine:

Glass bowl, plastic toy, steel spoon, cotton shirt

Ans. Glass bowl and steel spoon

Q.3. 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.

Ans.

Q.4. State whether the statements given below are ‘True’ or ‘False’.

(i) Stone is transparent, while glass is opaque.

(ii) A notebook has lustre, while an eraser does not.

(iii) Chalk dissolves in water.

(iv) A piece of wood floats on water.

(v) Sugar does not dissolve in water.

(vi) Oil mixes with water.

(vii) Sand settles down in water.

(viii) Vinegar dissolves in water.

Ans.

(i) Stone is transparent, while glass is opaque. (False)

(ii) A notebook has lustre, while an eraser does not. (False)

(iii) Chalk dissolves in water. (False)

(iv) A piece of wood floats on water. (True)

(v) Sugar does not dissolve in water. (False)

(vi) Oil mixes with water. (False)

(vii) Sand settles down in water. (True)

(viii) Vinegar dissolves in water. (True)

Q.5. 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

Ans.

(a) Round-shaped: Basketball, orange, globe, apple, earthen pitcher

Other shapes: Water, sugar

(b) Eatables: Water, orange, sugar, apple

Non-eatables: Basketball, globe, earthen pitcher

Q.6. List all items known to you that float on water. Check and see if they will float on oil or kerosene.

Ans. Some items that float on water are listed below:

1. Plastic bottle

2. Piece of paper

3. Piece of sponge

4. Piece of thermocol

5. Wood

6. Bamboo

7. Plastic ball

8. Cork

However, none of these items floats on oil or kerosene.

Q.7. Find the odd one out from the following:

(a) Chair, Bed, Table, Baby, Cupboard

(b) Rose, Jasmine, Boat, Marigold, Lotus

(c) Aluminium, Iron, Copper, Silver, Sand

(d) Sugar, Salt, Sand, Copper sulphate

Ans.

(a) Baby

(b) Boat

(c) Sand

(d) Sand

 

Chapter 5 – Separation of Substances

 

Q.1. Why do we need to separate different components of a mixture? Give two examples.

Ans. Different components of a mixture are separated in order to either separate the un-required components from a mixture or sometimes, to separate more than one useful components from a mixture.

For example, grain purchased from shops can contain several impurities such as pieces of stone, husk, broken grains, etc. Thus, grain is separated from these impurities to make it edible.

Similarly, after preparing tea, we strain it to remove the used tea leaves from tea.

Q.2. What is winnowing? Where is it used?

Ans. Winnowing is the process of separation of the heavier components from the lighter components of a mixture by wind or by blowing air.

It is generally used by farmers to separate the lighter impurities such as husk particles from the heavier grains.

Q.3. How will you separate husk or dirt particles from a given sample of pulses before cooking?

Ans. The dirt particles that are present in the pulses are removed by washing the latter with water. Being heavier, the pulses settle down, while the dirt particles being lighter keep floating in water. This process is called sedimentation. The dirty water can be removed by the method of decantation, leaving the pulses at the bottom.

Q.4. What is sieving? Where is it used?

Ans. Sieving is the method of separation of fine particles from bigger particles by allowing the finer particles to pass through the holes of a sieve, leaving the bigger particles in the sieve itself.

It is generally used in homes to separate flour from impurities such as pieces of stone, stalk, and husk. It is also used at construction sites to separate sand from small stones.

Q.5. How will you separate sand and water from their mixture?

Ans. Sand is not soluble in water. Hence, the mixture of sand and water can be separated by two methods:

1.    Combination of sedimentation and decantation: As sand is insoluble and heavier than water, it settles down at the bottom of the container containing the mixture. This process is called sedimentation. After the process of sedimentation is complete, water is slowly transferred to another container and sand remains in the original container. This process is called decantation.

2.    Filtration: the mixture is poured on a strainer or a piece of cloth or a filter paper so that the water goes through the strainer and the sand remains on the strainer.

Q.6. Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it?

Ans. Yes. It is possible to separate a mixture of sugar and wheat flour.

This can be done by the process of sieving. If the mixture of sugar and wheat flour is allowed to pass through a sieve, then the fine wheat flour particles would pass through the sieve, the sugar particles would be retained by the sieve.

Q.7. How would you obtain clear water from a sample of muddy water?

Ans. Clear water can be obtained from a sample of muddy water by the method of filtration. In this method, the sample of muddy water is poured through a cloth having fine pores or through a filter paper. Water will pass through the filtering medium, leaving behind the mud.

Q.8. 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 sea water 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 _________.

Ans.

(a) The method of separating seeds of paddy from its stalks is called __threshing__.

(b) When milk, cooled after boiling, is poured on a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of __filtration__.

(c) Salt is obtained from sea water by the process of __evaporation__.

(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 __decantation__.

Q.9. State whether the following statements are ‘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 through filtration.

(d) Grain and husk can be separated by the process of decantation.

Ans.

(a) A mixture of milk and water can be separated by filtration. (False)

(b) A mixture of powdered salt and sugar can be separated by the process of winnowing. (False)

(c) Separation of sugar from tea can be done through filtration. (False)

(d) Grain and husk can be separated by the process of decantation. (False)

Q.10. 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?

Ans. The solubility of a substance decreases with decreases in temperature. After the addition of ice, the temperature of the lemonade decreases and dissolving sugar in cold water is difficult. Therefore, ice should be added to lemonade after dissolving the sugar.

 

Chapter 6 – Changes around Us

 

Q.1. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?

Ans. Yes. The length of the dress can again be increased by unfolding it. Hence, this change can be reversed.

Q.2. You accidentally dropped your favourite toy and broke it. This is a change you did not want. Can this change be reversed?

Ans. No. This change cannot be reversed.

Q.3. Some changes are listed in the following table. For each change, write in the blank column, whether the change can be reversed or not.

Ans.

Q.4. A drawing sheet changes when you draw a picture on it. Can you reverse this change?

Ans. If we draw a picture on a drawing sheet with a pencil, we can get back the original drawing sheet by erasing the drawing with an eraser. In this case, the change can be reversed.

However, if we draw with a pen, then the original drawing sheet cannot be obtained back because we cannot erase ink. Hence, in this case, the change cannot be reversed.

Q.5. Give examples to explain the differences between changes that can or cannot be reversed.

Ans. To explain the differences between changes that can or cannot be reversed, some examples are given below:

(i) If we inflate a balloon, the size and shape of the balloon undergoes a change. However, the original size and shape of the balloon can be obtained back by allowing the air to escape from the balloon. This means that the change that occurs by inflating a balloon can be reversed. But, if the balloon bursts after being inflated, then its original size and shape cannot be obtained back. Thus, in this case, the change cannot be reversed.

(ii) If we fold a piece of paper, then the shape and size of the paper undergoes a change. In this case, the original shape and size of the original paper can be obtained back. Thus, this change can be reversed. However, if we cut the piece of paper, the change in the shape and size of the paper cannot be reversed.

(iii) After we roll out a chapatti from a ball of dough, the chapatti can be converted back into a ball. Thus, the change occurring here can be reversed. But, if we cook the chapatti on a tawa, then it cannot be converted back into a ball of dough. Thus, the change is irreversible.

Q.6. A thick coating of Plaster of Paris (POP) paste is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilized. Can the change in POP be reversed?

Ans. When water is added to plaster of Paris (POP), it changes to another substance and on drying it hardens. Once the POP has hardened, its shape cannot be changed. Therefore, the change in POP cannot be reversed.

Q.7. A bag of cement lying in the open gets wet due to rain during the night. The next day, the sun shines brightly. Do you think the changes that have occurred in the cement can be reversed?

Ans. In this case, the changes cannot be reversed. This is because the cement that hardens up after getting wet cannot be obtained back.

 

 

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