NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources
NCERT Solutions for Class 9 Science (physics) Chapter 15 Improvement in Food Resources are given below. In these solutions, we have answered all the intext and exercise questions provided in NCERT class 9 science textbook. Class 9 NCERT Solutions Science Chapter 15 provided in this article are strictly based on the CBSE syllabus and curriculum. Students can easily download these solutions in PDF format for free from our app.
Class 9 Science Chapter 15 Textbook Questions and Answers
PAGE NO. 204
Question 1: What do we get from cereals, pulses, fruits and vegetables?
Answer: (i) Cereals provide us with carbohydrates. Also, they are a rich source of energy.
(ii) Pulses give us proteins.
(iii) Fruits and vegetables are a rich source of vitamins and minerals. A small amount of proteins, carbohydrates, and fats are also present in them.
PAGE NO 205
Question 1: How do biotic and abiotic factors affect crop production?
Answer: Two 2 major factors that affect the crop are:
- Biotic factors like insects, rodents, pests, and many more spread the disease and reduce crop production.
- Abiotic factors like humidity, temperature, moisture, wind, rain, flood and many more destroy the crop raised.
Question 2: What are the desirable agronomic characteristics for crop improvements?
Answer: The desirable agronomic characteristics for crop improvements are:
(i) Tallness and profuse branching in any fodder crop.
(ii) Dwarfness in cereals.
These desirable agronomic characteristics help in increasing crop productivity.
PAGE NO 206
Question 1: What are macro-nutrients and why are they called macro-nutrients?
Answer: Macro-nutrients are nutrients required in relatively large quantities for growth and development of plants. They are six in number. Since they are required in large quantities, they are known as macro-nutrient. The six macro-nutrients required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.
Question 2: How do plants get nutrients?
Answer: Plants require sixteen essential nutrients from nature for their growth and development. All these nutrients are obtained from air, water, and soil. Soil is the major source of nutrients. Thirteen of these nutrients are available from soil. The remaining three nutrients (carbon, oxygen, and hydrogen) are obtained from air and water.
PAGE NO 207
Question 1: Compare the use of manure and fertilizers in maintaining soil fertility.
Answer: Manures increase soil fertility by enriching the soil with organic matter and nutrients as it is prepared by the decomposition of animal excreta and plant wastes. On the other hand, fertilizers are mostly inorganic compounds whose excessive use is harmful to the symbiotic micro-organisms living in soil. Their excessive use also reduces soil fertility. Hence, fertilizers are considered good for only short-term use.
Effects of manure are:
- Manure improves the soil quality with added nutrients.
- Manure provides extra organic matter called humus to the soil and therefore increasing the water retention capacity of sandy soils and drainage in clayey soil.
- Manures reduces soil erosion.
- They provide food for soil friendly bacteria which are helpful in growing crops.
Effects of fertilizers are:
- Fertilizers make the soil to become too dry and powdered and rises rate of soil erosion.
- The organic matter decreases by decreasing the porosity of soil hence, the plant roots do not get oxygen properly.
- The nature of soil changes either to basic or acidic.
PAGE NO 208
Question 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.
Answer: Option (c) will give the most benefits because use of good quality seeds is not only sufficient until the soil is properly irrigated, enriched with fertilizers and protected from biotic factors.
PAGE NO 209
Question 1: Why should preventive measures and biological control methods be preferred for protecting crops?
Answer: Over exposer of chemicals leads to environmental problems hence, biological methods are preferred for protecting crops from pathogens, insects and rodents along with increasing the production. Since chemicals are harmful for plants and also for the animals which feed on it, hence bio-pesticides are used as the safe way of crop protection.
Question 2: What factors may be responsible for losses of grains during storage?
Answer: 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 germinability, discolouration, etc.
PAGE NO 210
Question 1: Which method is commonly used for improving cattle breeds and why?
Answer: Cross breading is generally the best method adopted for improving the cattle breed quality. In this method, breeding is between two good cattle breed results in a new improved variety of cattle breed or offspring. While breeding it is taken care to have a good resultant with high yield having resistance to climatic conditions.
PAGE NO 211
Question 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.”
Answer: Poultry in India is the most efficient converter of low fibre food stuff into highly nutritious animal protein food. In poultry farming, domestic fowls are raised to produce eggs and chicken. For this, the fowls are given animal feeds in the form of roughage, which mainly consists of fibres. Thus, by feeding animals a fibre rich diet, the poultry gives highly nutritious food in the form of eggs and chicken
PAGE NO 211
Question 1: What management practices are common in dairy and poultry farming?
Answer: Common management practices in dairy and poultry farming are:
(i) Proper shelter facilities and their regular cleaning.
(ii) Some basic hygienic conditions such as clean water, nutritious food, etc.
(iii) Animals are kept in spacious, airy, and ventilated place.
(iv) Prevention and cure of diseases at the right time is ensured.
Question 2: What are the differences between broilers and layers and in their management?
Broilers: The poultry bird raised for meat purpose is called broiler. Broilers feed on protein rich adequate fat food. The level of vitamins A and K is kept high in the poultry feeds.
Layers: The egg laying poultry bird is called layer. The housing, environmental and nutritional requirements of broilers vary from those of egg layers. Layers require proper lightning and enough space.
Question 3. Discuss the implications of the following statement: “It is interesting to note that poultry is India’s most efficient converter of low fiber food stuff (which is unfit for human consumption) into highly nutritious animal protein food.”
Answer: Poultry farming aims in raising domestic birds for egg and chicken meat purpose. These domestic birds feed on animal feeds which mainly consists of roughages for getting good quality feathers, egg, chicken and nutrient rich manure. For this reasons, it is said that, “poultry is India’s most efficient converter of low fibre food stuff into highly nutritious animal protein food”.
PAGE NO 213
Question 1: How are fish obtained?
Answer: Fish can be obtained by two ways:
(i) Capture fishing: It is the process of obtaining fish from natural resources.
(ii) Culture fishery: It is the practice of farming fishes. Farming can be done in both freshwater ecosystem (which includes river water, pond water) and marine ecosystem.
Question 2: What are the advantages of composite fish culture?
Answer: Advantages of composite fish culture are:
- In a single fish pond, a combination of 5 or 6 types of fish species can be cultured since they do not compete for food among them.
- Food resource can be completely utilized
- Survival of the fish also increases
- More yield
PAGE NO 213
Question 1: What are the desirable characters of bee varieties suitable for honey production?
Answer: Bee varieties having the following desirable characters are suitable for honey production:(i) They should yield high quantity of honey.
(ii) They should not sting much.
(iii) They should stay in the beehive for long durations.
(iv) They should breed very well.
Question 2: What is pasturage and how is it related to honey production?
Answer: Pasturage is the availability of Blowers from which bees collect nectar and pollen. It is related to the production of honey as it determines the taste and quantity of honey.
Question 1: Explain any one method of crop production which ensures high yield.
Answer: Crop rotation is one of the methods of crop production that ensures high yield. It is the method of growing two or more varieties of crops on the same land in sequential seasons. A crop utilises some particular nutrients in larger quantities from the soil. Then, if the same crop is grown in subsequent seasons those nutrients will get depleted in the soil. Therefore, crops having different nutrient requirements are rotated. For example, legumes which have nitrogen-fixing bacteria in their root nodules supply the soil with nitrogen. Therefore, these legumes are rotated with nitrogen requiring cereals such as wheat and maize. This method reduces the need of fertilizers, thereby increasing the overall yield of crops.
Question 2: Why are manures and fertilizers used in fields?
Answer: Manures and fertilizers are used in fields to enrich the soil with the required
nutrients. Manure helps in enriching the soil with organic matter and nutrients. This improves the fertility and structure of the soil. On the other hand, fertilizers ensure a healthy growth and development in plants. They are a good source of nitrogen, phosphorus, and potassium. To get an optimum yield, it is instructed to use a balanced combination of manures and fertilizers in the soil.
Question 3: What are the advantages of inter-cropping and crop rotation?
Answer: Inter-cropping and crop rotation both play an important role in increasing the yield of crops. Inter-cropping helps in preventing pests and diseases to spread throughout the field. It also increases soil fertility, whereas crop rotation prevents soil depletion, increases soil fertility, and reduces soil erosion. Both these methods reduce the need for fertilizers. It also helps in controlling weeds and controls the growth of pathogens and pests in crops.
- Checks pests and rodents and hence decreases the chances of spoiling of whole crops.
- Decreased chances of soil erosion.
- Reduced loss of crops with high yield.
- Less water requirement.
- Farmers can grow two or three crops annually.
- Pulses take nitrogen directly from the atmosphere, and hence require minimal amount of fertilizers.
- Both fruits and Vegetables can be grown easily.
- Best use of land with proper supply of nutrients.
Question 4: What is genetic manipulation? How is it useful in agricultural practices?
Answer: Genetic manipulation is process in which the transfer of genes takes place from one organism to another. Here gene of a particular character is introduced inside the chromosome cell and hence results in a transgenic plant.
Example: BT Cotton is a genetically modified crop which carry bacterial genes, that protects this plant from insects. These are used in plants like brinjal, cabbage, rice, cauliflower, and maize crops to get protection from insects.
Question 5: How do storage grain losses occur?
Answer: Factors responsible for such losses are biotic— insects, rodents, fungi, mites and bacteria, and abiotic— inappropriate moisture and temperatures in the place of storage. These factors cause degradation in quality, loss in weight, poor germinability, discolouration of produce, all leading to poor marketability.
These factors can be controlled by proper treatment and by systematic management of warehouses.
Question 6: How do good animal husbandry practices benefit farmers?
Answer: Cattle farming is one of the methods of animal husbandry that is most beneficial for farmers. Using this method, better breeds of draught animals can be produced. Such draught animals are engaged in agricultural fields for labour work such as carting, irrigation, tilling, etc.
Question 7: What are the benefits of cattle farming?
Answer: Benefits of cattle farming are:
- Cattles are used in agricultural purpose
- Generation of good quality cattle
- Milking and meat purpose
- Skin of cattle is used for leather and wool industry
Question 8: For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer: For increasing the production, cross breeding techniques are used adopted in poultry, fisheries and bee-keeping. Along with these technique regular and proper maintenance methods are useful in improving the production.
Question 9: How do you differentiate between capture fishing, mariculture and aquaculture?
Answer: Capture fishing: It is the method of obtaining fishes from natural resources.
Mariculture: It is the culture of marine fishes for commercial use.
Aquaculture: It involves the production of aquatic animals that are of high economic value such as prawns, lobsters, fishes, crabs, etc.
Class 9 Science NCERT Solutions Chapter 15 Improvement in Food Resources
CBSE Class 9 Science NCERT Solutions Chapter 15 helps students to clear their doubts and to score good marks in the board exam. All the questions are solved by experts with a detailed explanation that will help students complete their assignments & homework. Having a good grasp over CBSE NCERT Solutions for Class 9 Science will further help the students in their preparation for board exams and other competitive exams such as NTSE, Olympiad, etc.
NCERT Solutions for Class 9 Science Chapter 15 PDF
Below we have listed the topics discussed in NCERT Solutions for Class 9 Science Chapter 15. The list gives you a quick look at the different topics and subtopics of this chapter.
|Section in NCERT Book||Topics Discussed|
|15.1||Improvement in Crop Yields|