CBSE Class 9 Science Natural Resources assignment

Mark (1)

1 Name the outer layer of the earth.

Q 2 Write the name of two organisms, which take part in the nitrogen fixation.

Q 3 Define hydrosphere.

Q 4 What is atmosphere?

Q 5 What is the percentage of CO2 on Venus?

Q 6 Define combustion.

Q 7 What is the role of ozone layer?

Q 8 What will happen if the CO2 concentration in the atmosphere increases?

Q 9 How can you describe global warming?

Q 10 How is Earth‘s atmosphere different from that of Venus and Mars?

Q 11 At what stage water is said to be polluted?

Q 12 Name the man-made component which is responsible for the depletion of ozone layer.

Q 13 How is ‗humus‘ formed?

Q 14 Why does the average temperature on earth remains fairly steady?

Q 15 What will be result if the CO2 concentration in the atmosphere increases?

Marks (2)

Q 16 Define photosynthesis, which gas is released as its byproduct?

Q 17 Define nitrogen fixation.

Q 18 What are the biotic and abiotic components?

Q 19 What are the mode of CO2 fixation?

Q 20 Define biosphere?

Q 21 How can you decide whether a given sample of water is polluted or non-polluted?

Q 22 Define humus and give its function.

Q 23 Define ammonification and nitrification.

Q 24 Why does the average temperature on earth remains fairly steady?

Q 25 Complete the boxes with appropriate natural resources and define the zone that comprises of all the three forms of life.

Q 26 Mention two methods through which living organisms influence the formation of soil.

Q 27 List two ways in which water is useful to living organisms.

Q 28 Mention any two human activities which would be responsible for air pollution.

Q 29 Give one visible indication of air pollution.

Q 30 What do you understand by fixed nitrogen?

Q 31 What is humus? Explain the role of earthworms in the formation of humus.

Q 32 Suggest any two measures for avoiding misuse and wastage of potable water.

Q 33 Identify the different components of the given cycle and name the cycle represented here.

Q 34 (i) What are the abiotic components of the biosphere?
(ii) Identify A, B and C in the given image:

Q 35 Why are fishes not able to survive in a water body that supports dense algal growth?

Q 36 Complete the missing links in the oxygen cycle:

Q 37 Expand the term ―CNG‖. Why is it known as an eco-friendly fuel?

Marks (3)

Q 38 What is the role of atmosphere in the climate control ?

Q 39 Draw a neat and clean diagram of C-cycle.

Q 40 What are pollutants? Give the different types of the air pollutants with example.

Q 41 Draw the labelled diagram of the O2 cycle.

Q 42 Why do organisms need water?

Q 43 What are the factors that make soil?

Q 44 Describe the wind movement in the coastal regions.

Q 45 What are the reasons which lead to water pollution?

Q 46 a) What is symbiosis?
b) Name a symbiotic life form.

Q 47 Sulphur dioxide and nitrogen dioxide gases react with the water vapour present in air. What are the products formed by this reaction? What is this process known as and what are its effects?

Q 48 (i) How is the earth‘s atmosphere different from that of Venus and Mars.
(ii) Mention any two human activities responsible for causing air pollution.

Q 49 Both UV-A and UV-B reach earth after passing through the ozone layer. But, as ozone layer is getting depleted, which of the two rays will be more harmful to earth and why?

Q 50 Smog is a serious problem in many countries and continues to harm human health. Justify.
 

Marks (5)

Q 51 What are the various methods to control pollution?

Q 52 Describe the nitrogen cycle.

Q 53 Describe the process which results in rain.

Q 54 Describe the effects of the air pollution.

Q 55 a) 'Greenhouse effect is the cause and global warming and climate change are the consequences', justify the statement.
b) Mention the cause of green house effect.

Q 56 a) Mention two ways by which water helps in formation of soil.
b) Explain oxygen cycle in nature with diagram.

Q 57 a) Mention two ways of mode of fixation of CO2.
b) Mention three ways by which carbon returns to the C-cycle.

Q 58 a) What are biogeochemical cycles?
b) Explain water or hydrological cycle in the nature with diagram.

Q 59 With the help of a labelled diagram,
a) show nitrogen cycle in nature.
b) list four steps involved in the cycling of N2 in the environment.

Q 60 a) With the help of a labelled diagram, show the cycling of carbon in nature.
b) What are the two ways in which carbon-di-oxide is fixed in the environment?

Q 61 (a) Name three processes through which oxygen is used from the atmosphere and one process through which oxygen is returned to the atmosphere.
(b) Mention three ways by which carbon returns to the C-cycle.

Q 62 (a) What is nitrogen fixation? Explain with the help of a diagram.
(b) Explain water cycle in nature.

Q 63 (i) Apart from natural calamities like floods, human beings are also responsible for causing soil erosion. Discuss various activities of humans that lead to soil erosion.
(ii) Mention one biotic and abiotic factor that contributes in the formation of soil.

Q 64 (i) With help of a labelled diagram, show nitrogen cycle in nature.
(ii) Describe briefly any two processes involved in the cycling of nitrogen in the atmosphere.

Q 65 (i) How does the movement of air bring about changes in the atmosphere?
(ii) What are the various factors that influence winds?
 

Most Important Questions

Q 1 What is the outer layer of the earth known as?

Q 2 What is hydrosphere.

Q 3 What is atmosphere?

Q 4 Give the percentage of CO2 on Venus?

Q 5 Differentiate between the biotic and abiotic components?

Q 6 Atmosphere plays an important role in the climate control. Justify the statement.

Q 7 What is biosphere?

Q 8 What is water pollution?

Q 9 Define pollutants? Give examples of different types of the air pollutants.

Q 10 Give the wind movement during day in the coastal regions.

Q 11 Give the important role played by the dust and other suspended particles in the air with respect to rain drop formation.

Q 12 Give one method to control air pollution?

Q 13 What is acid rain.

Q 14 What are the activities, which lead to water pollution?

Q 15 What is combustion?

Q 16 What is the function of ozone layer?

Q 17 What will be the immidiate result of decrease in atmospheric CO2 concentration?

Q 18 What is nitrogen fixation.

Q 19 Define global warming?

Q 20 Give the phenomenon of CO2 fixation?

Q 21 Give the function of humus.

Q 22 Give the consequence of global warming?

Q 23 Give two examples of nitrogen fixing microorganisms.

Q 24 Describe the O2 cycle.

Q 25 Give the biological importance of water?

Q 26 What is ammonification?

Q 27 Draw the diagram of the C-cycle.

Q 28 How is carbon resumed in the C-cycle?

Q 29 Amino acid is formed using which chemical form of nitrogen.

Exam Questions NCERT Class 9 Science Chapter 14 Natural Resources

Question. Which method is commonly used for improving cattle breeds and why?
Ans : Cross breeding between a two good variety crops is called hybridization that also results in a new improved variety. Another way of improving the crop is by introducing a gene that would provide the desired characteristic. This results in genetically modified crops.

Question. What factors may be responsible for losses of grains during storage?
Ans : During the storage of grains, various biotic factors such as insects, rodents, mites, fungi, bacteria, etc. and various abiotic factors such as inappropriate moisture, temperature, lack of sunlight, etc. are responsible for losses of grains. These factors act on stored grains and result in degradation, poor germ inability, discolouration, etc.

Question. List any six factors for which variety improvement in crops is done.
Ans :
(i) Higher yield,
(ii) Improved quality,
(iii) Biotic and abiotic resistance,
(iv) Change in maturity duration,
(v) Wider adaptability,
(vi) Desirable characteristics.

Question. Name two breeds of cows selected for long lactation period.
Ans : After giving the birth of a calf, a cow secretes milk. The duration of milk secretion of a cow that is the  period of time till which the cow secretes milk is known as lactation period. Brown Swiss and jersey are selected for their long lactation period.

Question. Name two fresh initiatives taken to increase the water availability for agriculture.
Ans : Two new irrigation systems have been developed to save water and increase the availability of water to the crops. These are :
(1) Drip irrigation system : Here, water is supplied to the roots of the plants directly in a drop wise manner. This prevents unnecessary wastage of water.
(2) Sprinkler system : Here water is sprinkled over the crops like it happens in rain. So, water is absorbed by the soil in a better way.

Question. How do plants get nutrients?
Ans : Nutrients are supplied to plants by air, water and soil. Air supplies carbon and oxygen, hydrogen comes from water and soil supplies the other thirteen nutrients to plants.

Question. What are the new varieties obtained by cross breeding of Indian and exotic breeds of poultry?
Ans : The new variety/traits obtained by cross breeding of Indian and exotic breeds of poultry are :
(i) Number and quality of chicks
(ii) Dwarf broiler parent for commercial chick production
(iii) Summer adaptation capacity/tolerance to high temperature
(iv) Low maintenance requirements
(v) Reduction in the size of the egg-laying bird with ability to utilise more fibrous and cheaper diet, formulated using agricultural by products.

Question. Distinguish between a mullet and a prawn.
Ans : Mullet is a type of fish while prawn is a crustacean. Both live in water and serve as a food supplement worldwide. Prawn belongs to group arthropoda whereas mullet belongs to group Pisces.

Question. What is composite fish culture system? Mention one merit and one demerit of this system.
Ans : The composite fish culture system is a technology to grow both local and imported fish species in the water in the paddy field. One problem with such composite fish culture is that many of these fish breed only during monsoon mixed with other species, one of the advantages is that fish do not compete for food.

Question. What are the different ways/methods of hybridisation?
Ans :
Hybridisation can be :
(i) Intervarietal – between different varieties of crops
(ii) Interspecific – between two species of same genus
(iii) Intergeneric – between two different genera

Question. What is organic farming?
Ans : Farming method in which no chemical fertilizers, pesticides or herbicides are used. Instead of using chemical, farmer uses all organic matter for growth of crops. Example : Manure, neem leaves as pesticides and for grain storage.

Question. Mention the components of food present in vegetable and fruits.
Ans : Vegetables, spices and fruits provide a range of vitamins and minerals in addition to small amounts of proteins, carbohydrates and fats.

Question. How does deficiency of nutrients affect the crop?
Ans : Physiological processes can be affected by deficiency of any nutrient in plants including reproduction, growth and susceptibility to diseases.

Question. What is Pisciculture?
Ans : The production and management of fish is called Pisciculture.

Question. What are the harmful effects of fertilizer?
Ans : Continuous use of fertilizer can cause of soil and water pollution and also destroy soil fertility.

Question. How does Bombay duck differ from common carp?
Ans : Bombay duck is a marine fish, while common carp is a freshwater fish.

Question. State the difference between compost and vermicompost.
Ans : The compost is obtained by decomposition of organic waste like animal excreta, plant waste, etc. naturally due to decomposition by bacteria. Vermi-compost : Red-worms are added to organic matter in the process of decomposition to obtain compost to fasten. This will fasten the process.

Question. Name any two weeds.
Ans : Parthenium and Xanthium.

Question. What causes disease in plants?
Ans : It is caused by pathogens such as bacteria, fungi and viruses.

Question. Name two Indian cattle.
Ans : Bos indicus - cows
        Bos bubalis - buffaloes

Question. Name any two fodder crops.
Ans : Berseem and sudan grass are raised as food for the livestock, called fodder crops.

Question. What do you understand by photoperiod of sunlight?
Ans : Photoperiod are related to the duration of sunlight required for plant growth.

Question. Define hybridisation.
Ans : Hybridisation refers to crossing between genetically dissimilar plants, to obtain better variety of crops.

Question. What are genetically modified crops?
Ans : A gene with required characters can introduce into a crop for its improvement is called genetically modified crop.

Question. How does Bos indicus differ from Bos bubalis?
Ans : Bos indicus is a cow while Bos bubalis is a buffalo.

Question. How do insect pests attack the plant and affect it?
Ans : Insect pests attack the plants and reduces yield in three ways :
(i) They cut the root, stem and leaf.
(ii) They suck the cell sap from various parts of the plant.
(iii) They bore into stem and fruits.

Question. Define manures. What are its three different kinds? State two limitations of manures.
Ans : Manure is an organic matter prepared by the decomposition of animal excreta and plant waste. They are : Compost, vermi-composting and green manure.
Two limitations of manures are :
(i) Supplies small quantities of nutrients to the soil
(ii) Losses about half the available nitrogen
(iii) Releases greenhouse gases

Question. What is the advantage of crop rotation?
Ans : Rotation of crops helps in saving on nitrogenous fertilizers, because leguminous plants grown during the rotation of crops can fix atmospheric nitrogen in the soil with the help of itrogen fixing bacteria.

Question. What are the types of food requirements of dairy animals? Why external and internal parasites live on and in the cattle can be fatal.
Ans : Roughage and concentrates are the types of food requirements of dairy animals. The external parasites live on the skin and mainly cause skin diseases. The internal parasites like worms, affect stomach and intestine while flukes damage the liver.
 
Question. Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
Ans : Sending crop to sugar factory " Irrigation " Harvesting " Sowing " Preparation of soil " Ploughing the field " Manuring Preparation of soil " Ploughing the field " Manuring
" Sowing " Irrigation " Harvesting " Sending crop to sugar factory.

Question. What are manures? Give its classification.
Ans : Substance rich in organic matter and also supplies small quantities of nutrients to soil is called manure. Manure is classified based on the kind of biological material used to make it as :
(i) Compost, (ii) Vermi-compost, (iii) Green manure.
(i) Compost : The manure prepared by decomposing farm waste, livestock excreta, plant waste, etc. in a pit is known as compost.
(ii) Vermi-compost : When the above given matter is allowed to decompose in the pit along with some earthworms to fasten the process of decomposition is called vermi-composting.
(iii) Green manure : Some plants like sun-hemp are used to prepare manure by mulching them into oil by plough is known as green manure.

Question. What are the different patterns of cropping?
or
What are the different cropping systems?
Ans : Different systems of growing crop :
(a) Mixed cropping : Two or more crops grow simultaneously on the same piece of land, is called mixed cropping.
Example : Wheat + grain, wheat + mustard.
(ii) Inter-cropping : It is a method of growing two or more crops simultaneously on the same field in a definite pattern. A few row of one crop alternate with a few rows of second crop.
Example : Soyabean + Maize or Bajra + Lobia.
(iii) Crop rotation : The growing of different crops on a piece of land in a succession is known as crop rotation.

Question. If wheat is sown in the kharif season, what would happen? Discuss.
Ans : The crop of wheat needs mild to moderate temperature and frost free days; along with irrigation but no water logging. Winters are suitable for growing wheat. In the kharif season; which coincides with the peak summer months in India, temperature is at its peak which is not suitable for wheat. Moreover, during rainy season lot of water accumulates in fields which would be harmful for wheat crop. Hence, if wheat is sown in the kharif season; the productivity would be minuscule and would not be profitable for the farmers.

Please refer to attached file for CBSE Class 9 Natural Resources