CBSE Class 8 Science Chapter Wise Question Bank Set 05

1. Fill in the blanks:

1. The two main crop seasons are __________season and _________ season.

2. __________ crops are grown during the rainy season. (June to September)

3. ___________ crops are grown during the winter season.(October to March)

4. Paddy is a ___________ crop.

5. Wheat and mustard are ______________ crops.

6. _____________ is a crop that is grown in standing water.

7. _____________________ is the first step before growing a crop.

8. ___________ and ___________organisms are called the friends of farmers which help in loosening the soil and adding humus to the soil.

9. ______________ and ____________ are the tools used in ploughing or tilling.

10. Dry soil has to be ______________ before ploughing.

11. _______ and _________tool can be used simultaneously for weeding and loosening the soil.

12. A tractor driven implement used for ploughing a field is called __________

13. Soil can be replenished through methods like ______________ and ______

14. Transplantation of plantlets into the field is done in the cultivation of the crops like ______________________.

15. The practice of leaving the field uncultivated is called __________________

16. _______________ is an organic substance obtained from the decomposition of plant or animal waste.

17. _____________ provides a lot of humus to soil.

18. ________________ are the chemical substances rich in particular nutrients.

19. _________system is a type of irrigation more useful on the uneven land and sandy soil.

20. Freshly harvested grains are sundried to remove ____________________.

21. Large scale storage of grains is done in ____________, _____________and __________.

I. Name the following:

1. The plant nutrients found in fertilizers: ______________________________

2. Any three sources of irrigation : ___________________________________

3. The nitrogen fixing bacteria found in the root nodules of leguminous plants: _______

4. The method of separating the grains from the chaff: __________________

5. The type of irrigation in which wastage of water is less: ________________

6. An example of weedicide: ________________________

7. Two weeding tools : ____________________________________________

8. Any two harvest festivals of India: _________________________________

9. Any two traditional methods of irrigation: ___________________________

10. A machine used for harvesting as well as threshing: ___________________

11. The science dealing with the study of food, shelter and health care of domestic animals:

2 MICRORGANISMS : FRIEND AND FOE

I. Fill in the blanks:

1. The pathogens are ____________ causing organisms.

2. The antibiotic first discovered By Alexander Fleming is called ___________.

3. _____________mosquito acts as the carrier of malaria causing parasite.

4. The most commonly used algae as fertilizers is ___________________.

5. Yeast cells produce alcohol and carbon dioxide by the process called ________

6. ________________ is the carrier of dengue virus.

II. Name the following:

1. Two single celled micro-organisms: ________________________________

2. Two multicellular micro-organisms: ________________________________

3. Two diseases caused by virus: ____________________________________

4. Two diseases caused by protozoa: ________________________________

5. Some diseases caused by bacteria: _________________________________

6. Two groups of micro-organisms that live in colonies: __________________

7. The micro-organism which promote curd formation: __________________

8. Two antibiotics: __________

9. Two communicable diseases: _____________

10. Two chemical preservatives: __________

11. The most common vaccine programme: ____________

12. The scientist who discovered fermentation: __________

III. Answer in short:

1. What is fermentation?

2. Who discovered the antibiotics?

3. Who discovered the vaccine for small pox?

4. How do pathogens enter in our body?

5. What are preservatives?

6. Which micro-organism is called as the nitrogen fixing bacteria?

CHAPTER :3 SYNTHETIC FIBRES AND PLASTICS

I. Fill in the blanks:

1. Many small units combine to form a large single unit called as ___________

2. ___________ fibre was prepared from coal, water and air.

3. All synthetic fibres are prepared using raw materials of petroleum origin called as _______.

4. ___________ is a familiar form of polyester used for making bottles, utensils, wires, and many useful products.

5. ____________ are the chemicals which give fruity smell.

6. Polythene is an example of __________

7. Plastics are _____________ conductors of electricity.

8. _____________ is the plastic used as non-stick coating on cookwares.

9. _____________ material is used to make rayon.

II. Name the following:

1. The artificial silk fibre: ____________

2. The first fully synthetic fibre: ______________

3. Any two thermoplastics: ___________

4. Any two thermosetting plastics: _____________

5. The synthetic wool: ___________

6. Any two items made from nylon: ____________

CHAPTER : 4 METAL AND NON METALS

I. Answer the following:

1. Which property of metals make them useful as wires?

2. What is the green material formed on copper when it is exposed to moist air for a long time?

3. Which property of the metals make them useful as ringing bells?

4. Identify the most reactive and the least reactive metal amongst the following: Aluminium, Potassium, Copper, Iron, Zinc, Gold.

5. What happens when iron is put into copper sulphate solution?

6. State the nature of non-metallic oxides.

7. State the nature of metallic oxides.

8. What happens when non-metals react with water?

II. Name the following:

1. The metal which exists in liquid state: __________

2. The hardest naturally occurring substance:____________

3. The non-metal which is a good conductor of electricity: ____________

4. Two soft metals which can be cut with knife: _____________

5. Any three non-metals: ___________

6. A non-metal used in water purification:____________

7. The gas produced on reaction of metals with bases: _______

CHAPTER: 5 COAL AND PETROLEUM

I. Answer the following in short:

1. What is petroleum?

2. Define the term refining

3. What do you mean by PCRA?

II. Name the following:

1. The gas used for street lightning in London in 1810: ___________

2. The fuel used in heavy vehicles: _____________

3. The fuel used in light vehicles: _____________

4. The gas which always collects above petroleum: _____________

5. The natural resource from which petrol and diesel are obtained: _________

III.Choose the correct answer:

1.Which of the following is not a fossil fuel?
(i) Natural gas
(ii) Wood
(iii) Coal.
(iv) Petrol

2. Which of the following is the fuel used in jet aircrafts?
(i) Petrol
(ii) Kerosene oil
(iii) Diesel
(iv) CNG

3. World’s first oil was drilled in:
(i) Assam
(ii) Saudi Arabia
(iii) Pennsylvania
(iv) Mumbai High

4. Naphthalene balls are obtained from :

5. Which gas is produced mainly on heating of coal strongly?
(i) Carbon mono-oxide
(ii) Methane gas
(iii) Carbon dioxide

CHAPTER: 6 COMBUSTION AND FUELS

I. Fill in the blanks:

1. A good fuel should have ___________ignition temperature. (high/low)

2. LPG, petrol and alcohol are __________ substances.

3. The hottest region of a candle flame is called __________.

4. Incomplete combustion of fuels releases poisonous ______________ gas in the air.

5. Increased percentage of carbon-dioxide in the air has been link to ______________.

6. ____________ form of fuels have the highest calorific value. (Solid/Liquid/Gaseous)

7. ______________ zone of a candle flame is the coolest region.

8. The head of safety match nowadays contains ____________ and __________.

9. Burning of fossil fuels release gaseous oxides of ___________, _____________ and ____________in the air.

10. Combustible substances are also called ____________.

11. Unburnt carbon particles in the air are dangerous pollutants causing ________ diseases.

12. ___________ combustion is responsible for outbreak of disastrous fires in coal mines. (Spontaneous/rapid)

II.Name the following:

1. The fuel with highest calorific value :___________

2. The fuel with lowest calorific value:____________

3. Two air pollutants related to acid rains:__________

4. Two inflammable substances:____________

5. The gas which helps in combustion:______________

6. Two common fire extinguishers:__________

7. Two chemicals which can be used as alternative source of CO2 for putting off fires:_____

III.Define the following:

(a) Combustion b) Calorific value c) Ignition temperature d) Inflammable substances

IV.Answer the following questions:

1. State four characteristics of a good fuel.

2. Burning of a candle produces flame while burning of charcoal doesnot. Give reason.

3. State two adverse effects of global warming.

CHAPTER :7 CONSERVATION OF PLANTS AND ANIMALS

I. Fill in the blanks:

1. Procuring land for cultivation leads to __________

2. Some natural causes of deforestation are _____________ and __________

3. __________ are the areas meant for conservation of biodiversity.

4. Biosphere reserve may also include within it other protected areas like __________ etc.

5. The plants and animals found in a particular area are termed as _________ and _________.

6. ____________ species are those species of plants and animals found exclusively in an area.

7. An ____________ is made of all plants, animals and micro-organisms in an area along with the non-living components such as climate, soil, river etc.

8. Red data book is the source book which keeps a record of all the __________ plants & animals.

9. Species which have disappeared from this earth are called __________ species.

10. _________ refers to the variety of plants ,animals and micro-organisms found in an area.

11. Members of a ___________ have common characteristics

II. Define the following:
a) Endemic species
b) Endangered species
c) Extinct species
d) Migration
e) Biodiversity