NCERT CLASS 9 SCIENCE CHAPTER 12 IMPROVEMENT IN FOOD RESOURCES
NCERT CLASS 9 SCIENCE
CHAPTER 12 – IMPROVEMENT IN FOOD RESOURCES
QUESTIONS AND ANSWERS
SECTION 1: IN-TEXT QUESTIONS AND ANSWERS
Q1. What do we get from cereals, pulses, fruits and vegetables?
Answer:
Cereals: They provide carbohydrates, which are the main source of energy.
Pulses: They provide proteins, which are required for growth and repair of the body.
Fruits and Vegetables: They provide vitamins and minerals, which protect our body from diseases and maintain good health.
Q2. How do biotic and abiotic factors affect crop production?
Answer:
Biotic factors: These include insects, pests, rodents, weeds, fungi and bacteria. They damage crops, cause diseases and reduce crop production.
Abiotic factors: These include temperature, humidity, drought, salinity, waterlogging, floods and soil conditions. They affect the growth and development of crops and may reduce their productivity.
Q3. What are the desirable agronomic characteristics for crop improvements?
Answer:
The desirable agronomic characteristics for crop improvement are:
Tallness and profuse branching are desirable characteristics for fodder crops because they produce more plant material for animal feed.
Dwarfness is desirable in cereal crops because dwarf plants require fewer nutrients and are less likely to fall due to strong winds or heavy rain.
Q4. What are macro-nutrients and why are they called macro-nutrients?
Answer: Macronutrients are the essential nutrients required by plants in large quantities for their growth and development.
They are called macronutrients because plants need them in comparatively large amounts.
Examples of macronutrients are:
Nitrogen
Phosphorus
Potassium
Calcium
Magnesium
Sulphur
These nutrients help in plant growth, photosynthesis, protein formation and other important life processes.
Q5. How do plants get nutrients?
Answer: Plants obtain nutrients from different natural sources.
Air: Plants obtain carbon and oxygen from the air.
Water: Plants obtain hydrogen and some oxygen from water.
Soil: Plants absorb minerals such as nitrogen, phosphorus, potassium, calcium and magnesium from the soil through their roots.
These nutrients are essential for the growth and development of plants.
Q6. Compare the use of manure and fertilizers in maintaining soil fertility.
Answer:
Manure:
Manure is a natural substance obtained by the decomposition of animal wastes and plant residues.
It adds organic matter or humus to the soil.
It improves soil texture and water-holding capacity.
It increases the number of useful microorganisms in the soil.
It releases nutrients slowly.
Fertilizers:
Fertilizers are commercially produced substances rich in specific plant nutrients.
They provide nutrients such as nitrogen, phosphorus and potassium.
They help plants grow faster when used in appropriate quantities.
Excessive use may damage soil health and cause water pollution.
They generally provide nutrients more quickly than manure.
Q7. Which condition will give the most benefits and why?
(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertilizers.
(c) Farmers use quality seeds, adopt irrigation, use fertilizers and use crop protection measures.
Answer:
Option (c) will give the most benefits.
Reasons:
Quality seeds help produce healthy and high-yielding crops.
Proper irrigation provides sufficient water for plant growth.
Fertilizers supply essential nutrients to crops.
Crop protection measures protect plants from pests, insects, diseases and weeds.
Therefore, combining all these methods helps increase crop production.
Q8. Why should preventive measures and biological control methods be preferred for protecting crops?
Answer: Preventive measures and biological control methods should be preferred because:
They are environmentally friendly.
They reduce the excessive use of chemical pesticides.
They help maintain soil fertility and ecological balance.
They reduce harmful effects on useful organisms.
They help prevent environmental pollution.
They provide safer and more sustainable methods of crop protection.
Q9. What factors may be responsible for losses of grains during storage?
Answer: The factors responsible for grain losses during storage are divided into two categories.
Biotic Factors:
Insects
Rodents
Fungi
Mites
Bacteria
Abiotic Factors:
Excessive moisture
High temperature
Improper storage conditions
These factors cause loss in weight, poor germination, discolouration and deterioration in the quality of stored grains.
Q10. Which method is commonly used for improving cattle breeds and why?
Answer: Cross-breeding is commonly used for improving cattle breeds.
It involves crossing indigenous breeds with exotic breeds to obtain desirable characteristics from both.
Advantages:
Indigenous breeds generally have better disease resistance and adaptability to local conditions.
Exotic breeds may have higher milk-producing capacity.
Cross-breeding can combine desirable qualities of both breeds.
It helps improve milk production and the overall quality of cattle.
Q11. What are the implications of poultry's efficiency in converting low-fibre food into animal protein?
Answer: Poultry birds can efficiently convert suitable feed into valuable animal products such as eggs and meat.
Its implications are:
Poultry farming provides an important source of animal protein.
It helps produce eggs and meat at a relatively low cost.
It provides employment and income to farmers.
It supports the poultry industry and food supply.
Poultry waste can also be used as manure.
Q12. What are the common management practices in dairy and poultry farming?
Answer: The common management practices in dairy and poultry farming are:
Providing proper and clean shelter.
Providing balanced and nutritious food.
Maintaining cleanliness and hygiene.
Providing clean drinking water.
Preventing diseases through proper healthcare.
Selecting healthy and productive breeds.
Q13. What are the differences between broilers and layers and their management?
Answer:
Broilers:
Broilers are poultry birds raised for meat production.
They require protein-rich and energy-rich food.
Their diet should contain adequate vitamins, especially vitamins A and K.
Proper temperature, hygiene and healthcare are necessary for their growth.
Layers:
Layers are poultry birds raised for egg production.
They require balanced food for proper growth and egg production.
They need adequate space and proper lighting.
Proper management helps maintain regular egg production.
Q14. How are fish obtained?
Answer: Fish are obtained through two main methods:
Capture Fishing: Fish are caught directly from natural water bodies such as rivers, lakes, ponds and seas.
Culture Fishery: Fish are bred and raised in controlled water bodies such as ponds, tanks and other fish-farming systems.
Q15. What are the advantages of composite fish culture?
Answer: Composite fish culture is a method in which several species of fish with different feeding habits are grown together in the same pond.
Advantages:
Different fish species feed in different zones of the pond.
Competition for food is reduced.
All available food resources of the pond are utilised efficiently.
It increases fish production.
It provides better economic returns to fish farmers.
Q16. What are the desirable characters of bee varieties suitable for honey production?
Answer: The desirable characteristics of bee varieties suitable for honey production are:
High honey collection capacity.
Less aggressive behaviour and less tendency to sting.
Ability to remain in the beehive for long periods.
Good breeding capacity.
Resistance to diseases.
These characteristics help increase honey production.
Q17. What is pasturage and how is it related to honey production?
Answer: Pasturage refers to the availability of flowers from which honeybees collect nectar and pollen.
The quantity and quality of pasturage directly affect honey production.
More flowers provide more nectar and pollen.
Different flowers influence the taste and quality of honey.
Good pasturage helps increase honey production.
The availability of flowering plants is important for the health and growth of honeybee colonies.
SECTION 2: EXERCISE QUESTIONS AND ANSWERS
Q1. Explain any one method of crop production which ensures high yield.
Answer: Inter-cropping is one of the methods of crop production that ensures high yield.
Inter-cropping is the practice of growing two or more crops simultaneously on the same field in a definite row pattern.
Advantages:
It makes better use of available nutrients.
It helps utilise water and sunlight efficiently.
It reduces the spread of pests and diseases.
It reduces the risk of complete crop failure.
It increases overall crop productivity.
Example: Growing soybean and maize together in alternate rows.
Q2. Why are manure and fertilizers used in fields?
Answer: Manure and fertilizers are used in fields to improve soil fertility and increase crop production.
Manure:
Adds organic matter to the soil.
Improves soil structure.
Increases water-holding capacity.
Promotes the growth of useful microorganisms.
Fertilizers:
Supply essential nutrients such as nitrogen, phosphorus and potassium.
Help in healthy plant growth.
Increase crop yield.
Correct nutrient deficiencies in the soil.
Therefore, manure and fertilizers help maintain soil fertility and improve agricultural production when used appropriately.
Q3. What are the advantages of inter-cropping and crop rotation?
Answer:
Advantages of Inter-cropping:
It makes better use of nutrients, water and sunlight.
It reduces the spread of pests and diseases.
It helps reduce the risk of crop failure.
It increases the total productivity of land.
It improves the utilisation of available resources.
Advantages of Crop Rotation:
It helps maintain soil fertility.
It prevents the continuous depletion of the same nutrients.
It reduces the accumulation of pests and diseases.
Growing leguminous crops helps improve nitrogen availability in the soil.
It increases agricultural productivity.
Q4. What is genetic manipulation? How is it useful in agricultural practices?
Answer: Genetic manipulation is the process of changing the genetic material of an organism to introduce desirable characteristics.
It is useful in agriculture in the following ways:
It helps develop high-yielding crop varieties.
It improves resistance against pests and diseases.
It helps develop crops that can tolerate drought and other unfavourable conditions.
It can improve the nutritional quality of crops.
It helps develop varieties suitable for different environmental conditions.
Example: Genetically modified crops can be developed to provide resistance against certain insect pests.
Q5. How do storage grain losses occur?
Answer: Storage grain losses occur due to biotic and abiotic factors.
Biotic Factors:
Insects
Rodents
Fungi
Bacteria
Mites
Abiotic Factors:
Excessive moisture
High temperature
Improper storage conditions
These factors cause:
Loss in weight of grains.
Reduction in grain quality.
Poor germination capacity.
Discolouration of grains.
Contamination and deterioration of stored food.
Proper drying, cleaning and storage help prevent these losses.
Q6. How do good animal husbandry practices benefit farmers?
Answer: Animal husbandry is the scientific management of livestock, including feeding, breeding, shelter and healthcare.
Good animal husbandry practices benefit farmers in the following ways:
They increase milk production.
They improve the quality of meat and eggs.
They improve the health of animals.
They help develop better animal breeds.
They reduce the chances of diseases.
They increase the income of farmers.
They provide manure for agricultural fields.
Q7. What are the benefits of cattle farming?
Answer: Cattle farming is useful for farmers in several ways.
Milk Production: Cattle provide milk, which is an important source of proteins, fats and other nutrients.
Draught Labour: Bullocks are used for agricultural activities such as ploughing and transportation.
Manure: Cattle dung is used as organic manure.
Biogas: Cattle dung can be used for producing biogas.
Income: Milk and other cattle products provide income to farmers.
Employment: Cattle farming creates employment opportunities in rural areas.
Q8. For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer: Poultry farming, fisheries and bee-keeping are different types of animal husbandry practices.
The common practices used to increase production are:
Selection of improved and productive breeds.
Providing proper and nutritious food.
Maintaining suitable environmental conditions.
Preventing diseases through proper healthcare.
Maintaining cleanliness and hygiene.
Using scientific breeding and management techniques.
These practices help increase production and improve the quality of animal products.
Q9. How do you differentiate between capture fishing, mariculture and aquaculture?
Answer:
Capture Fishing:
Capture fishing is the process of catching fish directly from natural water bodies such as rivers, lakes and seas.
Mariculture:
Mariculture is the practice of farming marine organisms in seawater.
Examples: Marine fish, prawns, oysters and seaweeds.
Aquaculture:
Aquaculture is the farming of aquatic organisms such as fish, prawns and other aquatic animals in freshwater or marine environments under controlled conditions.
SECTION 3: IMPORTANT ADDITIONAL QUESTIONS AND ANSWERS
Q1. What is food security?
Answer: Food security means ensuring that sufficient, safe and nutritious food is available and accessible to all people at all times.
Q2. Why is improvement in food resources necessary?
Answer: Improvement in food resources is necessary because:
The population is increasing.
Food demand is increasing.
Agricultural land is limited.
We need to improve the nutritional quality of food.
Higher food production is required to meet future needs.
Q3. What are the major sources of food?
Answer: The major sources of food are:
Plants: Cereals, pulses, fruits, vegetables and oilseeds.
Animals: Milk, meat, eggs, fish and other animal products.
Q4. What is crop variety improvement?
Answer: Crop variety improvement is the process of developing better varieties of crops with desirable characteristics such as high yield, improved quality and resistance to diseases.
Q5. What are the main objectives of crop variety improvement?
Answer: The main objectives are:
Higher crop yield.
Improved quality of produce.
Resistance to biotic and abiotic stresses.
Shorter maturity duration.
Wider adaptability.
Desirable agronomic characteristics.
Q6. What are Kharif crops?
Answer: Kharif crops are crops grown during the rainy season. They are generally sown at the beginning of the monsoon and harvested after the rainy season.
Examples: Paddy, maize, soybean, cotton and groundnut.
Q7. What are Rabi crops?
Answer: Rabi crops are crops grown during the winter season. They are generally sown in winter and harvested in spring.
Examples: Wheat, gram, peas, mustard and linseed.
Q8. What is crop production management?
Answer: Crop production management refers to the various agricultural practices used to increase crop production and maintain crop quality.
It includes:
Nutrient management.
Irrigation management.
Cropping patterns.
Crop protection management.
Q9. What are the three main cropping patterns?
Answer: The three main cropping patterns are:
Mixed Cropping.
Inter-cropping.
Crop Rotation.
Q10. What is mixed cropping?
Answer: Mixed cropping is the practice of growing two or more crops simultaneously on the same piece of land without a definite row arrangement.
Example: Growing wheat and gram together.
Q11. What is inter-cropping?
Answer: Inter-cropping is the practice of growing two or more crops simultaneously on the same field in a definite row pattern.
Example: Growing soybean and maize in alternate rows.
Q12. What is crop rotation?
Answer: Crop rotation is the practice of growing different crops one after another on the same field in a planned sequence.
It helps maintain soil fertility and reduces the accumulation of pests and diseases.
Q13. What is manure?
Answer: Manure is an organic substance obtained by the decomposition of plant and animal wastes. It adds nutrients and organic matter to the soil.
Q14. What is fertilizer?
Answer: Fertilizers are commercially manufactured substances containing specific plant nutrients such as nitrogen, phosphorus and potassium.
Q15. What is irrigation?
Answer: Irrigation is the artificial supply of water to agricultural fields at regular intervals for proper crop growth.
Q16. What are the main sources of irrigation?
Answer: The main sources of irrigation are:
Wells.
Canals.
Rivers.
Tanks.
Ponds.
Dams and reservoirs.
Q17. What are weeds?
Answer: Weeds are unwanted plants that grow along with crop plants in agricultural fields.
Examples: Xanthium, Parthenium and Cyperus rotundus.
Q18. What is weeding?
Answer: Weeding is the process of removing unwanted plants or weeds from agricultural fields.
Q19. What are pesticides?
Answer: Pesticides are substances used to control harmful pests that damage agricultural crops.
Q20. What is animal husbandry?
Answer: Animal husbandry is the scientific management of livestock, including feeding, breeding, shelter and healthcare, to obtain useful products such as milk, meat, eggs and wool.
Q21. What is cattle farming?
Answer: Cattle farming is the practice of raising and managing cattle for milk production, draught labour and other useful purposes.
Q22. What are milch animals?
Answer: Milch animals are animals that are reared mainly for milk production.
Examples: Cows and buffaloes.
Q23. What are draught animals?
Answer: Draught animals are animals that are used for agricultural work and transportation.
Example: Bullocks.
Q24. What is poultry farming?
Answer: Poultry farming is the practice of raising domestic birds such as chickens, ducks and turkeys for eggs and meat.
Q25. What are broilers?
Answer: Broilers are poultry birds raised mainly for meat production.
Q26. What are layers?
Answer: Layers are poultry birds raised mainly for egg production.
Q27. What is fish production?
Answer: Fish production is the process of obtaining fish through capture fishing or fish farming.
Q28. What is composite fish culture?
Answer: Composite fish culture is a method in which several species of fish with different feeding habits are reared together in the same pond to utilise all available food resources efficiently.
Q29. What is apiculture?
Answer: Apiculture is the scientific practice of rearing and managing honeybees for honey and beeswax production.
Q30. What is the importance of honeybees?
Answer: Honeybees are important because:
They produce honey.
They produce beeswax.
They help in pollination.
They improve the productivity of many flowering crops.
They support agricultural production.
SECTION 4: IMPORTANT DIFFERENCES
Q1. Differentiate between Kharif crops and Rabi crops.
Answer:
Kharif Crops:
These crops are grown during the rainy season.
They are generally sown at the beginning of the monsoon.
They are harvested after the rainy season.
Examples: Paddy, maize, soybean and cotton.
Rabi Crops:
These crops are grown during the winter season.
They are generally sown in winter.
They are harvested in spring.
Examples: Wheat, gram, peas and mustard.
Q2. Differentiate between manure and fertilizers.
Answer:
Manure:
It is a natural organic substance.
It is prepared from decomposed plant and animal wastes.
It adds humus to the soil.
It improves soil texture and water-holding capacity.
It generally contains nutrients in smaller concentrations.
Fertilizers:
They are commercially manufactured substances.
They contain specific plant nutrients.
They do not add humus to the soil.
They provide nutrients in concentrated forms.
Excessive use may damage soil and the environment.
Q3. Differentiate between mixed cropping and inter-cropping.
Answer:
Mixed Cropping:
Two or more crops are grown together on the same field.
There is no definite row arrangement.
It reduces the risk of complete crop failure.
Example: Wheat and gram grown together.
Inter-cropping:
Two or more crops are grown together in a definite row pattern.
Crops are planted in separate rows.
It helps in efficient use of nutrients and other resources.
Example: Soybean and maize grown in alternate rows.
Q4. Differentiate between inter-cropping and crop rotation.
Answer:
Inter-cropping:
Two or more crops are grown simultaneously on the same field.
Crops are arranged in a definite row pattern.
It improves the utilisation of available resources.
Example: Growing maize and soybean together.
Crop Rotation:
Different crops are grown one after another on the same field.
Crops are grown in a planned sequence.
It helps maintain soil fertility.
Example: Growing wheat followed by a leguminous crop.
Q5. Differentiate between biotic and abiotic factors.
Answer:
Biotic Factors:
These are living factors that affect crop production.
They include insects, pests, weeds, fungi and bacteria.
They cause crop damage and diseases.
Abiotic Factors:
These are non-living factors that affect crop production.
They include temperature, water, humidity, salinity and sunlight.
They affect the growth and development of crops.
Q6. Differentiate between broilers and layers.
Answer:
Broilers:
They are raised for meat production.
They require protein-rich and energy-rich food.
Their management focuses on rapid growth.
They are generally raised for a shorter period.
Layers:
They are raised for egg production.
They require balanced food for proper egg production.
Their management focuses on egg-laying efficiency.
They require suitable lighting and proper space.
Q7. Differentiate between capture fishing and culture fishing.
Answer:
Capture Fishing:
Fish are caught from natural water bodies.
No controlled breeding is necessary.
Examples include catching fish from rivers, lakes and seas.
Culture Fishing:
Fish are bred and raised in controlled water bodies.
Proper feeding and management are provided.
Examples include fish farming in ponds and tanks.
Q8. Differentiate between mariculture and aquaculture.
Answer:
Mariculture:
It involves farming marine organisms in seawater.
It is carried out in marine environments.
Examples include farming marine fish, prawns and oysters.
Aquaculture:
It involves farming aquatic organisms in controlled water environments.
It can be carried out in freshwater or seawater.
Examples include fish farming in ponds and marine fish farming.
SECTION 5: IMPORTANT NUMERICAL QUESTIONS
Note: This chapter is mainly based on biological and agricultural concepts. It does not contain standard numerical problems like Physics chapters. The following are useful practice questions based on basic calculations related to crop production.
Q1. A farmer produces 500 kg of wheat from 1 hectare of land. Calculate the production from 5 hectares if the yield remains the same.
Solution:
Production from 1 hectare = 500 kg
Total area = 5 hectares
Total production = 500 × 5
= 2500 kg
Answer: Total wheat production = 2500 kg.
Q2. A farmer produces 2000 kg of rice from 2 hectares of land. Calculate the yield per hectare.
Solution:
Total production = 2000 kg
Total area = 2 hectares
Yield per hectare = Total production/Total area
= 2000/2
= 1000 kg/hectare
Answer: Yield = 1000 kg per hectare.
Q3. A farmer uses 50 kg of fertilizer per hectare. Calculate the fertilizer required for 8 hectares.
Solution:
Fertilizer required per hectare = 50 kg
Total area = 8 hectares
Total fertilizer = 50 × 8
= 400 kg
Answer: Total fertilizer required = 400 kg.
Q4. A farmer harvests 6000 kg of maize. If 10% of the grains are lost during storage, calculate the quantity of grains remaining.
Solution:
Total production = 6000 kg
Storage loss = 10%
Loss = 6000 × 10/100
= 600 kg
Remaining grains = 6000 - 600
= 5400 kg
Answer: Remaining grains = 5400 kg.
Q5. A farmer produces 3000 kg of wheat and 2000 kg of rice. Calculate the total food grain production.
Solution:
Wheat production = 3000 kg
Rice production = 2000 kg
Total production = 3000 + 2000
= 5000 kg
Answer: Total food grain production = 5000 kg.
SECTION 6: IMPORTANT FORMULAE AND FACTS
Crop Yield:
Crop Yield = Total Crop Production/Total Cultivated Area
Total Crop Production:
Total Production = Yield per Hectare × Total Area
Percentage of Storage Loss:
Percentage Loss = (Quantity Lost/Total Quantity) × 100
Remaining Quantity:
Remaining Quantity = Total Quantity - Quantity Lost
Important Facts:
Kharif crops are grown during the rainy season.
Rabi crops are grown during the winter season.
Cereals are rich in carbohydrates.
Pulses are rich in proteins.
Fruits and vegetables provide vitamins and minerals.
Macronutrients are required by plants in large quantities.
Nitrogen, phosphorus and potassium are important plant nutrients.
Manure adds organic matter to the soil.
Fertilizers supply essential plant nutrients.
Inter-cropping involves growing two or more crops in a definite row pattern.
Crop rotation involves growing different crops in a planned sequence.
Poultry farming is done for egg and meat production.
Apiculture is the scientific management of honeybees.
SONAR is related to sound, whereas apiculture is related to honeybee farming.
Composite fish culture helps utilise different feeding zones of a pond.
SECTION 7: IMPORTANT ONE-MARK QUESTIONS
Q1. What are the main energy-giving nutrients obtained from cereals?
Answer: Carbohydrates.
Q2. Which food group is rich in proteins?
Answer: Pulses.
Q3. Name two important Rabi crops.
Answer: Wheat and gram.
Q4. Name two important Kharif crops.
Answer: Paddy and maize.
Q5. What is the full form of HYV?
Answer: High Yielding Variety.
Q6. Name two examples of macronutrients.
Answer: Nitrogen and phosphorus.
Q7. What is the main function of manure?
Answer: It adds organic matter and improves soil fertility.
Q8. Which crop is commonly grown to improve nitrogen availability in the soil?
Answer: Leguminous crops.
Q9. What is irrigation?
Answer: The artificial supply of water to crops is called irrigation.
Q10. What are weeds?
Answer: Unwanted plants growing along with crops are called weeds.
Q11. What is weeding?
Answer: The removal of unwanted plants from agricultural fields is called weeding.
Q12. What is inter-cropping?
Answer: Growing two or more crops simultaneously in a definite row pattern is called inter-cropping.
Q13. What is crop rotation?
Answer: Growing different crops one after another on the same field in a planned sequence is called crop rotation.
Q14. What is animal husbandry?
Answer: Scientific management of livestock is called animal husbandry.
Q15. What is apiculture?
Answer: The scientific rearing and management of honeybees is called apiculture.
Q16. What is poultry farming?
Answer: Raising domestic birds for eggs and meat is called poultry farming.
Q17. What are broilers?
Answer: Poultry birds raised for meat production are called broilers.
Q18. What are layers?
Answer: Poultry birds raised for egg production are called layers.
Q19. What is mariculture?
Answer: Farming marine organisms in seawater is called mariculture.
Q20. What is aquaculture?
Answer: Farming aquatic organisms in controlled water environments is called aquaculture.
Q21. What is composite fish culture?
Answer: Rearing several fish species with different feeding habits together in one pond is called composite fish culture.
Q22. What is pasturage?
Answer: The availability of flowering plants that provide nectar and pollen to honeybees is called pasturage.
Q23. Which animal is commonly used for agricultural draught work?
Answer: Bullock.
Q24. What is the main purpose of cattle farming?
Answer: Milk production and draught labour.
Q25. What is the main objective of crop variety improvement?
Answer: To develop crop varieties with higher yield and desirable characteristics.
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