NCERT Solutions Class 9 Science Chapter 15 Improvement in Food Resources

NCERT Solutions Class 9 Science Chapter 15 Improvement in Food Resources

NCERT Solutions Class 9 Science Chapter 15 Improvement in Food Resources: National Council of Educational Research and Training Class 9 Science Chapter 15 Solutions – Improvement in Food Resources. NCERT Solutions Class 9 Science Chapter 15 PDF Download.

NCERT Solutions Class 9 Science Chapter 15: Overview







Chapter Name

Improvement in Food Resources

Exercise Solutions

NCERT Solutions Class 9 Science Chapter 15 – Improvement in Food Resources


Q1. What do we get from cereals, pulses, fruits and vegetables?

Ans: Cereals like wheat, rice, maize are sources of carbohydrate which is utilized to produce energy. Pulses such as gram, pea, lentil supply the body with protein. Vegetables and fruits along with spices provide the body with minerals, vitamins. They also supply carbohydrates, proteins and fats in small amounts.

Q2. How do biotic and abiotic factors affect crop production?

Ans: Both biotic and abiotic factors significantly affect crop production.

  • Biotic factors include living organisms like insects, nematodes and other pest organisms which consume the crops as well as cause disease in these crops as well.
  • Abiotic factors include extreme changes in the environment like drought, salinity, water logging, heat, cold and frost etc. can affect crop production.

Q3. What are the desirable agronomic characteristics for crop improvement?

Ans: The desirable agronomic characteristics for crop improvement include the following:

  • The fodder crop should be tall and must be highly branched.
  • On the other hand, cereal crop should de dwarf variety’s which consume less nutrients.

Q4. What are macro-nutrients and why are they called macronutrients?

Ans: Macro-nutrients are the nutrients which are required by the plants in very large quantities. They directly contribute to the growth and development in plants. Examples of micro nutrients obtained from the soil include nitrogen, phosphorus, potassium, calcium, magnesium, Sulphur etc.

Q5. How do plants get nutrients?

Ans: Plants require a number of nutrients for their growth and development. Air provides the plants with carbon and oxygen, whereas water supplies hydrogen and soil supplies the plants with both micro and macro nutrients.

Q6. Compare the use of manure and fertilizers in maintaining soil fertility.

Ans: 1) Manure:

  • Manure supplies small quantities of nutrients and organic matter to the soil making it fertile and prevent soil erosion.
  • Manure also improves soil structure.
  • It increases water retionsion capacity of sandy soil and helps in avoiding drainage in clayey soil.
  • Fertilizers:
  • Fertilizers supply soil with nitrogen, phosphorous, potassium artificially.
  • The organic matter thus does not get replenished, leading to soil erosion and infertile soil.

Hence fertilizers should be used for only a short period of time and long-term use of manure should be preferred.

Q7. 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:From the above conditions, Option (c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures will give the most benefits. All factors like good quality of seeds, proper irrigation and use of manure and fertilizer will result in increase in crop production.

Q8. Why should preventive measures and biological control methods be preferred for protecting crops?

Ans: Biological methods are much safer than chemical methods. Chemical methods can cause soil erosion, reduce the fertility of soil. Apart from this if used in excess these chemicals get deposited in plants and animal leading to biomagnification.

Q9. What factors may be responsible for losses of grains during storage?

Ans: Both biotic and abiotic factors are responsible for losses of grains during storage like insects, rodents, fungi, mites and bacteria, inappropriate moisture content and temperatures in the place of storage.

Q10. Which method is commonly used for improving cattle breeds and why?

Ans:Cross- breeding is carried out improving cattle breeds. Using this method, a new improved variety with better quality like long lactation periods and resistance against local diseases can be developed in cattle.

Q11. 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.”

Ans: Low fiber food stuff is obtained from agricultural by-products. This is very cheap, fibrous and highly nutritious as animal feed. Hence these agriculture products are India’s most efficient converter of low fiber food stuff (which is unfit for human consumption) into highly nutritious animal protein food

Q12. What management practices are common in dairy and poultry farming?

Ans:Both cattle and poultry are susceptible to disease so it is important to maintain proper clean and sanitary conditions in dairy and poultry farms. Apart from these vaccines also prevent incidences of diseases in both the animals. Both dairy and poultry farming involve maintaing proper nutritional management practices to increase yield and quality of meat, eggs and milk.

Q13. What are the differences between broilers and layers and in their management?

Ans:1.) Broilers are the birds raised for chicken meat where as layers are the birds which are cultured for eggs. Broilers are fed with food which is rich in protein and fat. Poultry feed is also supplemented with vitamin A and K. 2.) Apart from this environmental and shelter of broilers and layers is quite different. Care has to be taken to maintain temperature conditions and hygienic conditions in the poultry shelters.

Q14. How are fish obtained?

Ans: Capture fishing and culture fishing are the two ways to obtain fish. The capture fishing involves getting fishes from their natural habitat. Culturing fish is known as fish farming where fishes are cultured in rivers, ponds and seas.

Q15. What are the advantages of composite fish culture?

Ans: There are a number of advantages of composite fish culture such as:

  • More than 5 to 6 different types of fishes can be grown in composite fish culture.
  • This is possible as there is a lack of competition for food in these fishes
  • In this way no resources are wasted and the yield of fishes has increased.

Q16. What are the desirable characters of bee varieties suitable for honey production?

Ans:The desirable characters of bee varieties suitable for honey production are as follows:

  • The bees should have high honey collection capacity.
  • The bees should not sting much to facilitate bee farming.
  • The bees should breed well
  • The bees must stay in the hives for a log period.

Q17. What is pasturage and how is it related to honey production?

Ans: Pasturage is the quality and quantity of flowers accessible for honey production. The type of flowers will define the quality of honey.

  • Exercise Questions

Q1. Explain any one method of crop production which ensures high yield.

Ans: The 3 important activities for improving crop yields are classified as follows:

1.) Crop variety improvement

2.) Crop production improvement

3.) Crop protection management

Crop rotation is one of the strategies used to increase crop production and also ensure high yield. Different combinations of crops are grown one after the other in a way that maximum nutrients are used. It also reduces incidences of diseases in crops. both crops have better yields. If croprotation is carried out correctly then about 2 or 3 crops can be cultivated in a year.

Q2. Why are manure and fertilizers used in fields?

Ans: Manures and fertilizers are used to increase the fertility of the soil. They supply the soil organic matter which helps in improving crop yield. Fertilizers provide macronutrients like nitrogen, potassium and phosphorous to the soil. they increase the water retention capacity and enrich the soil with nutrients.

Q3. What are the advantages of inter-cropping and crop rotation?

Ans: The advantages of inter-cropping are as follows:

  • It helps in making use of all the nutrients of soil.
  • It is a good pest management practice.
  • It is a framing practice which prevents all the plants in the field to infected by a disease.

The advantages of Crop-rotation are as follows:

  • It is helpful to increase crop yield.
  • More than two or three crops can be grown at a time.
  • It helps in utilization of plant nutrients.

Q4. What is genetic manipulation? How is it useful in agricultural practices?

Ans: Genetic manipulation is process by which a gene of desired quality is inserted in other plant. It is useful as it helps in increasing the crop yield. It also induces disease resistance in crops example: transgenic crops.

Q5. How do storage grain losses occur?

Ans: Storage losses occur due to the following reasons like insects, rodents, fungi, mites and bacteria, inappropriate moisture contentand temperatures in the place of storage.

Q6. How do good animal husbandry practices benefit farmers?

Ans: Good animal husbandry practices benefits farmers in a number of ways. It adds to the income of the farmers. It also helps in division of labor to carry out agriculture practices like irrigation, tilling etc.

Q7. What are the benefits of cattle farming?

Ans: Cattle farming has two major advantages:

  • It is used to obtain milk and other related dairy products.
  • Cattle can also be used to do agricultural work like tilling, irrigation and ploughing.

Q8. For increasing production, what is common in poultry, fisheries and bee-keeping?

Ans:For increasing production in poultry, fisheries and bee-keeping proper sanitary conditions need to be maintained to keep the birds, fishes etc. disease free. Along with this cross-breeding techniques are used to increase production.

Q9. How do you differentiate between capture fishing, mariculture and aquaculture?

Ans:1.) Capture fishing is a method of obtaining fishes from their natural resources like rivers, ponds etc.

2.) Mariculture: It is a fish farming practice of culturing fish from marine water.

3.) Aquaculture: This is a fish farming technique which involves in culturing of fish in estuaries and lagoons culture.

Updated: November 23, 2021 — 12:08 pm

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