KENDRIYA VIDYALAYA CRPF AVADI CHENNAI -65
WINTER HOLIDAY HOMEWORK (2015 – 16)
SUB: SCIENCE STD: VIII
24.12.15
I Fill in the blanks :
1.Burning of wood and coal causes ----------- of air.
2.A liquid fuel, used in homes is -------------------.
3. Fuel must be heated to its -----------.
4. Fire produced by oil cannot be controlled by --------------.
5. Fossil fuels are -------, ----------------- and -------------.
25.12.15
6. Process of separation of different constituents from petroleum is called ----------.
7.Least polluting fuel for vehicle is --------------------.
8. Animals which give birth to young ones are called ----------------.
9. Amoeba reproduces by -------------------.
10. Testes produce -----------------.
Answers:
1.
Pollution 2. Kerosene 3. Ignition temperature 4. Water. 5. Coal, petroleum and natural gas
6. refining 7. CNG. 8. Viviparous 9. Binary fission. 10. Sperms.
ONE WORD QUESTIONS:
26.12.15:
1. A petroleum product used for surfacing road:
2. Minimum temperature at which a substance catches fire:
3. The common name of peat, lignite, bituminous and anthracite:
4. An example of slow combustion:
27.12.15
5. An example of exhaustible natural resource:
6. Embedding of the embryo in the uterine wall :

KENDRIYA VIDYALAYA CRPF AVADI CHENNAI -65
WINTER HOLIDAY HOMEWORK (2015 – 16)
SUB: SCIENCE STD: VIII
7. The substance having the highest calorific value is
8. The number of nuclei present in a zygote is :
9. The unit in which the calorific value of a fuel is expressed :
10. A tadpole develops into an adult frog by the process of :
Answers:
1.
Bitumen. 2. Ignition temperature 3. Coal 4. Cellular respiration 5. Petroleum/ wildlife/coal/mineral 6. Implantation 7. Hydrogen 8. One. 9. Kilojoule per Kg 10.
Metamorphosis.
28.12.15
Answer the following:
1.
What is metamorphosis?
2.
Give two differences between a zygote and a foetus.
3.
Difference between rapid combustion and spontaneous combustion.
Answers:
1.
The process of development of a tadpole into an adult frog is called is called metamorphosis.
2.
Zygote: 1. It is made up of a single cell. 2. It is formed by fusion of male and female gamate.
Foetus: 1. It is made up of many cells. 2. It is formed by the repeated divisions of the zygote.
3.
Rapid combustion : The combustion in which gas burns rapidly and produces heat and light.
Spontaneous combustion: The combustion in which a material suddenly bursts into flames without application of any apparent cause.
29.12.15
1. List conditions under which combustion takes place:
2. Compare LPG and wood as a fuel.
3. What are the advantages of using CNG and LPG as fuels?
Answers:
1.
Combustible substance, low ignition temperature and air.
2.
LPG: 1. More calorific value. 2. Smoke free 3. Easy to transport 4. Easy to store
Wood: 1. Less calorific value 2. Produces smoke 3. Difficult to transport 4. Difficult to

KENDRIYA VIDYALAYA CRPF AVADI CHENNAI -65
WINTER HOLIDAY HOMEWORK (2015 – 16)
SUB: SCIENCE STD: VIII store as it needs lot of space.
3.
These are cleaner fuels . Easy to transport. Easily available. Pollution free
30.12.15.
Give reasons:
1.
Water is not used to control fires involving electrical temperature.
2.
LPG is a better domestic fuel than wood.
3.
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.
Answers:
1.
Water is a good conductor of electricity
2.
Refer answer number 2 of 29.12.15.
3.
The heat supplied to the paper is transferred to aluminium pipe by conduction. So in the presence of aluminium rod, the ignition temperature of paper is not reached, Hence it does not burn.
31.12.15
1. Describe characteristics and uses of coke.
2. Which zone of a flame does a goldsmith use for melting gold and silver and why?
3. In which female reproductive organ does the embryo get embedded?
Answers:
1.
It is a tough, porous and black substance. It is an almost pure form of carbon. Coke is used in the manufacture of many metals.
2.
Outer zone ( blue flame)
3.
Wall of the uterus
1.1.2016
1. Describe how coal is formed from dead vegetation. What is this process?
2. What are inflammable substances?
Answers:

KENDRIYA VIDYALAYA CRPF AVADI CHENNAI -65
WINTER HOLIDAY HOMEWORK (2015 – 16)
SUB: SCIENCE STD: VIII
1.Millions of years ago many plants got buried under the layers of earth. Under high pressure and temperature , dead plants got slowly converted to coal. This process is called carbonization.
2. The substances which have very low ignition temperature and can easily catch fire with a flame.
2.1.2016
1. Define asexual reproduction.
2. Describe two methods of asexual reproduction in animals .
Answer-The reproduction in which a single parent is involved is called asexual reproduction. Budding and Binary fission are the methods of asexual reproduction.
Budding -Hydra reproduces by budding. Many bulges develop on the body of hydra.
Each bulge grows into a new individual. Bulges are called buds.
Binary fission -Amoeba reproduces by binary fission. At first the nucleus divides into two nuclei and then the mother cell divides into two; with each part receiving a nucleus.
3.1.2016
1.
Make a labeled diagram of a candle flame.
2.
Draw a well labeled diagram of female reproductive system .
Question : 1 Question : 2

KENDRIYA VIDYALAYA CRPF AVADI CHENNAI -65
WINTER HOLIDAY HOMEWORK (2015 – 16)
SUB: SCIENCE STD: VIII