NCERT Solutions
In-Text Questions Answers:
Q1. What do we get from cereals, pulses, fruits, and vegetables?
Ans: Cereals primarily provide carbohydrates, which are essential for energy. Pulses are rich in proteins, crucial for growth and body repair. Fruits and vegetables are key sources of vitamins, minerals, and fibers, all necessary for maintaining overall health and enhancing immunity.
Q2. How do biotic and abiotic factors affect crop production?
Ans: Biotic factors such as pests and diseases can significantly reduce crop yields by damaging plants. Abiotic factors, including temperature, humidity, and rainfall, also play a crucial role in influencing crop growth, either positively or negatively.
Q3. What are the desirable agronomic characteristics for crop improvements?
Ans: Ideal characteristics include high yield potential, resistance to diseases and pests, adaptability to various environmental conditions, and efficient nutrient utilization. For instance, shorter plant height in cereals can help in preventing lodging and enhance the crop’s resilience.
Q4. What are macro-nutrients, and why are they called macronutrients?
Ans: Macronutrients are nutrients required by plants in larger quantities for their growth and development. These include elements like nitrogen, phosphorus, and potassium, which are crucial for various plant functions such as growth, photosynthesis, and protein synthesis.
Q5. How do plants get nutrients?
Ans: Plants absorb essential nutrients from the soil through their roots. Carbon and oxygen are obtained from the air and water, while other nutrients like nitrogen, phosphorus, and potassium are absorbed from the soil. Some plants can also fix atmospheric nitrogen through symbiotic relationships with microorganisms.
Q6. Compare the use of manure and fertilisers in maintaining soil fertility.
Ans: Manure, an organic substance, enriches the soil with nutrients and improves soil texture, enhancing water retention and aeration. Fertilizers, on the other hand, are chemical substances that provide specific nutrients to the soil, leading to immediate but sometimes short-term improvements in plant growth.
Q7. Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds; do not adopt irrigation or use fertilisers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertiliser.
(c) Farmers use quality seeds, adopt irrigation, use fertiliser and use crop protection measures.
Ans: Option (c) offers the most benefits as it combines the use of high-quality seeds with essential agricultural practices like proper irrigation, fertilization, and crop protection measures, ensuring optimal growth and yield of crops.
Q8. Why should preventive measures and biological control methods be preferred for protecting crops?
Ans: Preventive measures and biological control are preferred as they are environmentally sustainable, reduce the reliance on chemical pesticides, and help in maintaining the ecological balance. These methods include using natural predators or biopesticides to control pests, thus minimizing harm to the crops and the environment.
Q9. What factors may be responsible for the losses of grains during storage?
Ans: Losses during grain storage can be attributed to biotic factors like pests, rodents, fungi, and bacteria, and abiotic factors such as improper moisture levels, temperature fluctuations, and inadequate storage conditions leading to spoilage and quality degradation of grains.
Q10. Which method is commonly used for improving cattle breeds and why?
Ans: Cross-breeding is commonly used for improving cattle breeds. It involves mating of superior breeds to combine desirable traits from both, resulting in offspring with improved productivity, disease resistance, and adaptability to local conditions.
Q11. What management practices are common in dairy and poultry farming?
Ans: Common management practices include providing hygienic shelter and adequate space, ensuring a balanced diet with proper nutrients, regular health check-ups to prevent diseases, and maintaining appropriate environmental conditions for the animals’ comfort and productivity.
Q12. What are the differences between broilers and layers and their management?
Ans: Broilers are raised for meat production, requiring a protein-rich diet and specific environmental conditions to enhance growth rate. Layers are raised for egg production, needing a balanced diet rich in calcium and a controlled lighting environment to stimulate egg-laying.
Q13. Discuss the implications of the following statement: “Poultry is India’s most efficient converter of low-fibre foodstuff into highly nutritious animal protein food.”
Ans: This statement highlights poultry’s ability to efficiently convert agricultural by-products and low-fibre food, which are not suitable for human consumption, into high-quality protein in the form of meat and eggs. This contributes significantly to food security and nutrition.
Q14. How are fish obtained?
Ans: Fish are obtained through capture fishing, which involves catching fish from natural water bodies like seas, rivers, and lakes, and through aquaculture, which involves breeding and rearing fish in controlled environments like ponds and tanks.
Q15. What are the advantages of composite fish culture?
Ans: Composite fish culture allows for the simultaneous farming of different fish species in a single pond. This maximizes the use of pond resources as different species feed at different water levels and have varying food habits, leading to increased overall fish production.
Q16. What are the desirable characteristics of bee varieties suitable for honey production?
Ans: Desirable characteristics include high honey yield, gentle nature, less swarming behavior, good disease resistance, and efficiency in foraging and converting nectar into honey.
Q17. What is pasturage, and how is it related to honey production?
Ans: Pasturage refers to the availability and variety of flowering plants from which bees collect nectar and pollen. The quality and quantity of honey depend greatly on the pasturage, as different flowers provide nectar with varying flavors and nutritional profiles.
Exercise Questions Answers:
1) Explain any one method of crop production which ensures high yield.
Ans: One effective method is crop rotation, which involves growing different types of crops in succession on the same land. This practice helps in maintaining soil fertility, reducing soil erosion, and controlling pests and diseases, thereby ensuring higher yields.
2) Why are manure and fertilizers used in fields?
Ans: Manure and fertilizers are used to replenish essential nutrients in the soil, thereby enhancing its fertility and productivity. They provide vital nutrients like nitrogen, phosphorus, and potassium, which are crucial for the healthy growth and development of plants.
3) What are the advantages of inter-cropping and crop rotation?
Ans: Inter-cropping involves growing two or more crops simultaneously on the same field, which helps in optimizing the use of resources and reducing pest and disease incidences. Crop rotation prevents soil depletion, breaks pest and disease cycles, and improves soil structure and fertility.
4) What is genetic manipulation? How is it useful in agricultural practices?
Ans: Genetic manipulation involves altering the genetic makeup of plants to enhance desirable traits such as disease resistance, drought tolerance, and higher yield. This is beneficial in developing crop varieties that can adapt to various environmental stresses and meet the increasing food demand.
5) How do storage grain losses occur?
Ans: Storage grain losses occur due to biotic factors like insects, rodents, fungi, and bacteria, and abiotic factors such as moisture, temperature, and improper storage techniques. These lead to degradation in grain quality, reduction in germination capacity, and potential health hazards.
6) How do good animal husbandry practices benefit farmers?
Ans: Good animal husbandry practices, which include proper feeding, housing, disease control, and breeding management, lead to increased production of milk, eggs, and meat, improved animal health and productivity, and higher economic returns for farmers.
7) What are the benefits of cattle farming?
Ans: Cattle farming provides multiple benefits including milk and meat production, use of cattle in agricultural tasks like plowing and transportation, production of manure for fertilizers, and the generation of by-products like leather and wool.
8) For increasing production, what is common in poultry, fisheries, and bee-keeping?
Ans: Common practices include selective breeding and genetic improvement to enhance productivity, efficient feeding and nutritional management, disease control and prevention, and adoption of modern farming techniques for optimal production.
9) How do you differentiate between capture fishing, mariculture, and aquaculture?
Ans: Capture fishing involves harvesting fish from natural water bodies. Mariculture refers to the cultivation of marine organisms in seawater environments, often for luxury seafood. Aquaculture encompasses the breeding, rearing, and harvesting of aquatic organisms in controlled freshwater and marine environments.