1st Term
Based On chapters 1 to 8
6th Science IMOPRTANT Q&A(Semi) for 1st Term
6th Science IMOPRTANT Q&A(Semi) for 1st Term
Q.1.A. Fill in the blanks using proper words.
1. Nylon thread was developed simultaneously in New York and London.
2. Dermis and epidermis are the two layers of the human skin.
3. Rayon is also known as synthetic silk.
4. Rubber made by vulcanization is a manmade material.
5. The human skeletal system is divided into two parts.
6. The process of intake of food and utilising it for all life processes is called nutrition.
7. Cells of the epidermis contain a pigment called melanin.
8. Carbohydrates and fats provide energy to our body.
9. In a balanced diet, all the nutrients are present in the adequate proportion.
10. All the substances in our food which are useful for various bodily processes are called nutrients.
11. Intake of more food than necessary causes obesity.
12. The layer of ozone gas absorbs ultraviolet rays that come from the sun to the earth
B. Choose the correct alternative.
(a) The ................ joint is seen in fingers and toes.
(1) Hinge joint (3) Ball and socket joint
(3) Immovable joint (4) Gliding joint
(b) ………. provide maximum energy to the body.
(1) Cereals (2) Leafy vegetables
(3) Water (4) Amla
(c) Goitre is caused by a deficiency of the mineral ………. .
(1) iron (2) calcium
(3) iodine (4) potassium
(d) ………. is a type of junk food.
(1) Orange (2) Milk
(3) Bhakri (4) Chocolate
(e) The system which gives a definite shape to our body.
(1) Excretory system (2) Respiratory system
(3) Skeletal system (4) Circulatory system
(f) Pulses are a very good source of ………. .
(1) carbohydrates (2) proteins
(3) fats (4) minerals
C. Match the pairs.
Group ‘A’ Answers Group ‘B’
(1) Oxygen (c ) (a) Rain
(2) Water vapour (a ) (b) Plants and food
production
(3) Microbes (g ) (c) Combustion
(4) Ball and socket joint (f ) (d) Knee
(5) Hinge joint (d ) (e) Wrist
(6) Gliding joint (e ) (f) Shoulder
(7) Carbon dioxide (b ) (g) Generation of soil
Answers :
(1) Oxygen - (c) Combustion
(2) Water vapour -
(3) Microbes - (g) Generation of soil
(4) Ball and socket joint - (f) Shoulder
(5) Hinge joint - (d) Knee
(6) Gliding joint - (e) Wrist
(7) Carbon dioxide - (b) Plants and food production
Q.2.A. Right or wrong ?
(a) The water in a lake is called ground water.- wrong
(b) Radon is used in decorative lights.- wrong
(c) Land and soil are the same thing.- wrong
(d) Bones are soft. - wrong
(e) It takes about 1000 years to form a 25 cm thick layer of soil.- wrong
(f) The human skeleton protects the internal organs.- right
B. Who am I?
(a) I dissolve in water, but not in kerosene.- sodium / salt
(b) I make things hot or cold.- heat
(c) I have no shape whatsoever!- liquid / gas
(d) I’m found in a thermometer; I measure your temperature.- mercury
C. What are we used for ?
(1) Wood:
Ans. Furniture is made from wood. The doors and windows of houses are also
made from wood. Therefore, in construction activities wood is largely used.
Wood also gives fuel. Many other useful articles are also made from wood.
(2) Paper :
Ans. Paper is for writing, for making books,
notebooks, registers, greeting cards, etc. Tissue paper is used for wiping.
Lots of paper is also used as packing materials.
(3) Nylon :
Ans. Nylon threads are durable and hence used in
making ropes, fishing nets and clothes.
(4) Rubber
:
Ans. Rubber is used to make tyres of all vehicles.
For this, hard vulcanized rubber is used. Erasers, rubber toys, balls,
footwear, rubber bands are many articles made from rubber.
(5) Soil:
Ans. Soil is used for farming and agriculture. It
is also used in constructions. Bricks and clay tiles are made from soil. Pots,
urns, clay stoves, etc. are made from soil.
D. Note the temperatures.
|
Some examples |
Temperature |
|
Boiling water |
1000C |
|
Freezing water |
00C |
|
Air (winter night) |
< 150C |
|
Air (summer afternoon) |
> 350C |
|
Inside a fridge |
< 50C |
|
Inside the freezer |
< - 180C |
|
Human
body temperature Approx. |
370C |
Q.3.A. Answer in your own words.
1. What are the different
types of bones ? How many types are there ?
Ans. There are four main types of bones according to their shapes. They are (1)
Flat bones (2) Irregular bones (3) Small bones (4) Long bones.
2. The
handle of a cooker is made of plastic. Why?
Ans. Pressure Cooker is made from mixed metals
such as hindalium or aluminium. When it is on cooking fire, it becomes hot. If
we lift it up in a hurry, we may get burnt. To avoid this the handle of cooker
is made from plastic. Plastic is not thermal conductive material. Therefore, we
may not feel the heat of the cooker while lifting it up.
3. From
which substances in nature can we get threads or fibre?
Ans. We get threads and fibres from cotton, wool, jute, hemp, silk, etc.
(4) What is
sublimation? Write the names of everyday substances that sublimate,
Ans. The change in the solid substance upon heating,
directly into a gas or vapour without changing into liquid is called sublimation.
The substances that show
sublimation are: Camphor, Naphthalene balls, Iodine crystals, Ammonium chloride
or nausagar.
(5) How are
metals obtained?
Ans. Metals are found in the form of minerals deep
inside the earth's crust. They are removed and processed to obtain metals.
B. Give scientific reasons.
(1) The ozone layer is a
protective shell of the earth.
Ans. Ultraviolet rays of the sun are very harmful for
the living organisms present on the earth. The ozone layer present at the high
altitude around the earth, absorbs these harmful radiations. The life on the
earth is thus protected.
Therefore, the ozone layer is called a protective
shell of the earth.
(2) Water is life.
Ans. Living organisms cannot survive without water. The
blood of the animals and sap of the plants also have high proportion of water.
Therefore, water is said to be life.
(3) Man-made materials have
more demand.
Ans. Man-made material is easy to use, low in
cost, available in plenty. The original natural materials are changed into
man-made material to suit our convenience. e.g. instead of cotton and wool
fibres, synthetic fibres are more convenient for use. Plastic and thermocol are
the materials that has fast replaced the natural alternatives. Thus, man-made
material has more demand.
(4) Humus
is a natural material.
Ans. There are soil microbes that bring about decomposition process in the soil.
From the dead and decaying remains of animals and plants humus is formed by
them. This is a natural process and therefore humus is called a natural
material.
.
