Class 9 Science Chapter 15 Improvement in Food Resources

NCERT Class 9 Science Chapter 15 Improvement in Food Resources Question Answer to each chapter is provided in the list so that you can easily browse throughout different chapters Class 9 Science Chapter 15 Improvement in Food Resources and select need one.

NCERT Class 9 Science Chapter 15 Improvement in Food Resources

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Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given SCERT Class 9 Science Chapter 15 Improvement in Food Resources Solutions for All Subjects, You can practice these here.

Improvement in Food Resources

Chapter – 15




Textbook Page No.204

1. What do we get from cereals, pulses, fruits and vegetables? 

Ans.The cereals provide us with carbohydrates. The pulses provide us with proteins. Fruits and vegetables give us carbohydrates, protein, fat, vitamins, minerals and lots of fibers.

Textbook Page No. 205

1. How do biotic and abiotic factors affect crop production?

Ans. The different biotic and abiotic factors of the environment affect the net crop production in various ways. Insects, nematodes, birds and diseases are biotic factors. These biotic factors mostly feed on crops and thus they draw nutrition from them reducing their yeild. Similarly, abiotic factors such as drought, salinity of soil, water logging in croplands, heat, cold, etc. also reduce the net crop production. Some natural calamities like flood, droughts, etc. are always unpredictable and therefore their occurrence sometimes damages the entire crops. Both biotic and abiotic factors can cause heavy loss in the crop production.

2. What are the desirable agronomic characteristics for crop improvements? 

Ans. The desirable agronomic characteristics for higher productivity of crops are – tallness and profuse branching in fodder crops and dwarfness in cereal crops. Profuse branching gives high biomass in fodder crops and less nutrients are consumed by dwarf cereal plants resulting into high cereal production. 

Textbook Page No. 206

1. What are macronutrients and why are they called macronutrients?

Ans. There are six essential nutrients required relatively in large quantities for growth and development of a plant. These nutrients are nitrogen, phosphorus, potassium, calcium, magnesium and sulphur and they are called macronutrients. Since, these are required in larger amount, they are called so.

2. How do plants get nutrients?

Ans. Plants get seventeen (17) essential nutrients from their environment. Air supplies carbon and oxygen, water provides hydrogen and soil supplies the other thirteen essential minerals to plants. Roots absorb these nutrients from the soil. All these nutrients are acquired by plants during various physiological processes.

Textbook Page No. 207

1. Compare the use of manure and fertilizers in maintaining soil fertility. 

Ans. Manure is composed of organic matter obtained by the decomposition of animal excreta and plant waste, whereas fertilizers are man-made substances commercially produced as plant nutrients. Manure helps in enriching soil with nutrients and organic matter and increasing soil fertility. It also helps in improving soil structure. Moreover, use of manure is advantageous in protecting our environment. It is a way of recycling farm waste. On the other hand, fertilizers supply nitrogen, phosphorus and potassium ensuring higher yields of high-cost farming. However, fertilizers should be applied very carefully in terms of proper amount, time and observing pre and post-application precautions. Excessive and frequent use of fertilizers often destroys soil fertility and also harms symbiotic micro-organisms living in soil. Thus, we can conclude that manure has a long-term benefit to soil as compared to the short-term benefits of fertilizers.

Textbook Page No. 208

1. Which of the following conditions will give the most benefits? Why? 

(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.

(b) Farmers use ordinary seeds, adopt irrigation and use fertilizer.

(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures. 

Ans. (c) Farmers using quality seeds, adopting irrigation, using fertilizer and crop protection measures will achieve the most benefits. 

This is because quality seeds have the improved desired characters such as resistance to diseases, response to fertilizers, high yield, etc. and are of same variety and they germinate under the same field condition. Quality seeds also have various desired characters against natural hazardness and good response to fertilizer. This in turn facilitate fertilizer uptake. Adoption of various irrigation measures will help the farmer to fight against the drought condition. Adequate crop protection measures against weeds, insects, pests and various plant diseases will help him to grow more healthy crops.

Textbook Page No. 209

1. Why should preventive measures and biological control methods be preferred for protecting crops?

Ans. Various pesticides sprayed on crop plants, seeds or soil to fight against the crop pests, weeds and diseases are poisonous chemicals. These are harmful to both plant and animal species and their excessive use even causes environmental pollution. Whereas, preventive measures include proper soil and seed preparation, timely sowing of seeds, mixed cropping, intercropping and use of resistant varieties of crops. Moreover, biological methods include the usage of specific organisms which destroy specific weeds on application. One simple example is the use of Grass Carps to control aquatic weeds. Thus, all the preventive measures and biological control methods are safe and eco-friendly and hence preferred for protecting crops. 

2. What factors may be responsible for losses of grains during storage?

Ans. The factors may be responsibles foe losswes of grains during storages are mentioned below: 

(i) Biotic factors: Biotic factors such as insects, rodents, mites, birds, fungi, bacteria and other micro-organisms take nutrients from or feed on grains and results in their loss of yield.

(ii) Abiotic factors: Abiotic factors such as deficiency in moisture, low or high temperature in the place of storage and difference in humidity cause degradation in overall quality, loss in weight and poor germinability, etc.

Textbook Page No. 210

1. Which method is commonly used for improving cattle breeds and why?

Ans. Cattle farming is commonly used for improving cattle breeds. One of the important aims of cattle breeding is to get more production of milk which can be increased by increasing the lactation period. Foreign breeds (exotic) such as Jersey, Brown Swiss, etc. have long lactation period and these are cross-breed with local breeds such as Red Sindhi, Sahiwal, etc. that have excellent resistance to animal diseases. This common method of cross-breed between exotic and local breeds is done by the process of artificial insemination. This technique helps to achieve much desired quality progenies in a more economic way.

Textbook Page No. 211

1. Discuss the implications of the following statement: “It is interesting to note that poultry is India’s most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food.” 

Ans. ‘Low fibre food stuff” means the agricultural by-products and various roughage which are non-edible for humans, but can be used as a good and nutritious diet for egg-laying birds in poultry farming. Highly nutritious animal protein food, i.e. egg and chicken are thus the result of conversion of such low fibre food stuff, unfit for human consumption into production of most effective animal protein food for humans. 

Textbook Page No. 212

1. What management practices are common in dairy and poultry farming?

Ans. Though different methods are applied for higher production in dairy and poultry farming, there are some common management practices essential for every situation. 

These are: 

(i) Maintenance of optimum temperature in housing of cattle and poultry.

(ii) Maintenance of hygienic condition in house or farm area by proper cleaning, sanitation, etc.

(iii) Prevention and control of diseases and pests in the farm area by spraying disinfectants at regular intervals and proper vaccination to fight against certain diseases. 

(iv) All methods of quality maintenance in the cattle and poultry feed to maintain level of protein, vitamin, fat, etc. for different breeds.

2. What are the differences between broilers and layers and in their management?

Ans. The basic differences between broilers and layers are in the purpose of their production. In broilers, meat production is aimed where as egg production is the main aim in the production of layers.In poultry management, when layers are concerned, the aim is to manage good food and condition to increase quantity and quality of eggs. But when broilers are concerned, fast growth and low mortality are aimed by making their daily food requirements enriched with protein-rich diet including adequate fat and high level of vitamins A and K. The housing and environmental requirements of broilers are also different from those of layers. They need more care than general egg layers, i.e. they require more hygienic condition in housing and vaccination to control certain diseases.

Textbook Page No. 213

1. How are fish obtained?

Ans. There are two methods by which fish can be obtained, viz.

(i) Capture fishing, where fish are obtained from natural water sources. 

(ii) Culture fishery, where fish farming is done in artificial water sources.

2. What are the advantages of composite fish culture? 

Ans. Composite fish culture or polyculture of fish is a method where different types of fishes are cultured together in a bounded water body. It has many advantages over the monoculture method. 

Some of the advantages of composite fish culture are:

(i) High production of different types of fishes with low cost investment.

(ii) Species of different feeding habits are selected and hence competition among the species is lowered and the food available in all parts of the water body is used.

(iii) All the different species indirectly help in the growth of each other.

Textbook Page No. 214

1. What are the desirable characters of bee varieties suitable for honey production?

Ans. Following characters are desirable in a bee variety suitable for honey production:

(i) High honey collection capacity. 

(ii) Well-breeding nature with less swarming period.

(iii) Good defence mechanism against enemies.

2. What is pasturage and how is it related to honey production?

Ans. Pasturage is the group o flowering flora or plants which provides pollens and nectar to the honey bees for honey pr duction. A good pasturage should be available in the vicinity of an apiary to facilitate pollen and nectar collection by the honey bees. A good pasturage has good quality of pollens which provide protein food for worker bees and these indirectly effect the quality and taste of the honey.


Textbook Page No. 214-215

1. Explain any one method of crop production which ensures high yield. 

Ans. One of the important methods of crop production for high yield is mixed cropping pattern. It is a practice where two or more crops are simultaneously grown on the same crop field. The basic aim behind such cropping pattern is to minimise the risk of crop failure due to abnormal climatic conditions. There are different criteria for selection of the crops for mixed cropping. While selecting crops it is kept in mind that the by-products or wastes of one crop can be used for the benefit of other crops. For example, if a cereal crop is grown with leguminous crop, it (cereal) gets benefit from the legumes of the roots of leguminous plants which fix atmospheric nitrogen. Leguminous plants also increase the fertility of soil for the benefit of all other crops. Besides, one crop must not compete with other crops for nutrients and water. This can be achieved by selecting crops of shorter and longer harvesting period, using deep and shallow soil, tall and dwarf structures, etc. which have no competition among themselves for survival and growth. For example, groundnut is mixed with sunflower, wheat can be mixed with mustard, etc.

By adopting this method, small and marginal farmers get more benefit from the same crop field with same labour and this method also utilises all the environmental factors in the field and inter-helping nature of crops have effective result in crop yield.

2. Why are manure and fertilizers used in fields? 

Ans. Manure and fertilizers are the main sources of nutrient supply to soil and crops. Continuous use of the same cropland leads to deficiency of mineral nutrients in soil. Manure improves the physical and chemical texture of soil and fertilizers compensate the depleted nutrients in soil. To increase fertility of soil, manure and fertilizers are used in fields. Some specific fertilizers are also used on specific need of some inorganic nutrients of crop plants.

3. What are the advantages of inter-cropping and crop rotation? 

Ans. The advantages of inter-cropping are are mentioned below:

(i) Utilisation of same cropland with its environment for different crops.

(ii) Soil erosion is checked by inter-cropping. 

(iii) Maximum utilisation of nutrients in the field by both the crops.

(iv) Since sowing time and harvesting time of two crops are different, specific fertilizers can be used at different times and threshed separately.

(v) Inter-cropping also prevents pests and diseases from spreading to all the plants belonging to one crop in a field.

The advantages of crop rotation are mentioned below: 

(i) Specific pathogens of a particular crop can be controlled by crop rotation with non-host crop plants. 

(ii) Nitrogen deficiency of soil can be overcome by the use of leguminous crops which can fix atmospheric nitrogen in crop rotation. 

(iii) It is cost effective in the sense that some labour of agricultural practices like ploughing is reduced, where single ploughing is enough for two or more crops in a season. 

(iv) Deep soil and top soil, both the components of soil that can be utilised by crop-rotation of deep and shallow rooted crops.

(v) Different seasonal crops can be grown depending on seasonal variation in moisture and irrigation facilities.

4. What is genetic manipulation? How is it useful in agricultural practices?

Ans. Genetic manipulation means uniting of desirable genetic characters from similar organisms into a single organism, generally a crop plant. This may be done by various methods like hybridisation, mutation, polyploidy or by DNA recombination technology. All these methods result into union of desirable characters taken from parent organisms having characteristics likehigh -yielding capacity, disease resistance, etc. into a single genetically modified organism. Genetic manipulation is an effective way of crop improvement.

In all agricultural practices, farmers aim at high yield with good quality production along with resistance to different diseases. By genetic manipulation, genes of such desirable characters can be incorporated into a single genetically modified crop taken from different similar crop varieties. This results into a phenotypically strong crop with all desired characters and benefits the farmers to set in their goals.

5. How do storage grain losses occur? 

Ans. The factors responsible for losses of grains during storage are mentioned below: 

(i) Biotic factors: Biotic factors such as insects, rodents, mites, birds, fungi, bacteria and other micro-organisms take nutrients from or feed on grains and results in their loss of yield. 

(ii) Abiotic factors: Abiotic factors such as deficiency in moisture, low or high temperature in the place of storage and difference in humidity cause degradation in overall quality, loss in weight and poor germinability, etc.

6. How do good animal husbandry practices benefit farmers?

Ans. In commercial livestock farming, farmers always aim at economic benefit and to get this they have to look for good management practices. Animal husbandry is the scientific management of animal livestock. It has four basic aspects, viz. shelter, feeding, breeding and disease control. The nutritional requirement for different cattles, poultry and fish are different and should be well balanced and for this proper care has to be taken. While livestock production is concerned, proper breeding methods are necessary to get good quality progenies with desirable characteristics and above all the progenies must have disease resistance capacity with more vitality. All these can be obtained by practicing good animal husbandry practices and these help the farmers to achieve desired result in the business by reducing input cost with higher financial returns.

7. What are the benefits of cattle farming?

Ans. The benefits of cattle farming are mentioned  below: 

(i) Cattles provide milk for domestic consumption as well as for commercial purposes. 

(ii) The dung provided by the cattle can be used as organic manure and as fuel in the form of biogas or gobar-gas.

(iii) Some people rear cattles to get meat. These, can be used as meat for commercial purpose.

(iv) Cattle hides are used to prepare different leather items. 

(v) Some of the cattles can be used to drive carts as a medium of transportation. 

(vi) Different body parts of cattles after their death can be used to prepare commercial goods such as bones, horns and hoofs are used to prepare glue and gelatin. 

(vii) Cattles can also be used in different agricultural practices like ploughing related activities.

8. For increasing production, what is common in poultry, fisheries and bee-keeping? 

Ans. For increasing production in poultry, fisheries and in apiculture (bee-keeping), a balanced nutrient diet is must which has a direct effect in the production. In case of poultry, protein, fat and vitamin rich diet, in fisheries, good quality fish food and for apiculture a good quality pasturage are necessary. In all such farming, for increasing yield of desired quality products, the feeding practice with accessory management practices like breeding and disease control management and selection of improved varieties are common.

9. How do you differentiate between capture fishing, mariculture and aquaculture? 

Ans. When fish are obtained from natural water bodies such as seas, rivers, lakes, ponds, etc. by capturing, it is termed as capture fishing. Sometimes, some marine fish of high economic value are farmed (not captured only) in coastal seawater or marine water. This practice is termed as mariculture. On the other hand, aquaculture includes the production of all aquatic animals (such as fish, prawns, crabs, etc.) and aquatic plants of high economic value. Mariculture is a type of aquaculture.

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