NCERT solution for class 9 science improvement in food resources ( Chapter 15)

Solution for Exercise Questions

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

Plant breeding is one of the method adopted for high yield plant breeding and is implemented to improve the varieties of crops by breeding plants. Plants from various places/areas are picked up with preferred traits and then the process of hybridization or cross-breeding is done among these diversities to get a crop/plant of anticipated characteristic.

Q2. Why are manure and fertilizers used in fields?
Answer :

Manures and fertilizers are used to enrich the soil quality and improve the yield. They also help in controlling the diseases. Manure and fertilizers replenish the soil by supply nutrients to the soil. They are excellent source of potassium, phosphorous and nitrogen which assist in healthy development of plants. Manures and fertilizers mainly improve the fertility of the soil.

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

Advantages of Inter-Cropping are:

1. Checks pests and rodents and hence decreases the chances of spoiling of whole crops.

2. Decreased chances of soil erosion.

3. Reduced loss of crops with high yield.

4. Less water requirement.

Advantages of Crop-rotation are:

1. Farmers can grow two or three crops annually.

2. Pulses take nitrogen directly from the atmosphere, and hence require minimal amount of fertilizers.

3. Both fruits and Vegetables can be grown easily.

4. Best use of land with proper supply of nutrients.

Q4. 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.

Genetic manipulation is useful in providing better yielding varieties, disease and pest resistance plants.

Q5. How do storage grain losses occur?
Answer :

Storage grain losses occur due to:

Biotic factors like: Rodents, pests, insects, fungi, bacteria.

Abiotic factors like sunlight, flood, rain, temperature, moisture.

Q6. How do good animal husbandry practices benefit farmers?
Answer :

Good practice of animal husbandry benefits farmers by following ways:

1. Yields in good quality cattle.

2. Better quality of milk production.

3. Use in agriculture for carting, irrigation and tilling.

Q7. What are the benefits of cattle farming?
Answer :

Benefits of cattle farming are:

1. Cattles are used in agricultural purpose.

2.Generation of good quality cattle,

3. Milking and meat purpose.

4. Skin of cattle is used for leather and wool industry.

Q8. 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.

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

Solution for Intext Question

Q. What do we get from cereals, pulses, fruits and vegetables?
Answer :

Cereals provides us carbohydrate and is main reason of energy.Pulses provide protein for growth and development. Vegetables and fruits provides us with minerals, vitamins, carbohydrates, proteins and fats for overall development.

Q. How do biotic and abiotic factors affect crop production?
Answer :

Crops production can go down due to biotic (diseases, insects and nematodes) and abiotic (drought, salinity, water logging, heat, cold and frost) stresses under different situations. Varieties resistant to these stresses can improve crop production.

Q. What are the desirable agronomic characteristics for crop improvement?
Answer :

Tallness and profuse branching are desirable characters for fodder crops. Dwarfness is desired in cereals, so that less nutrients are consumed by these crops. Thus developing varieties of desired agronomic characters help give higher productivity.

Q. What are macro-nutrients and why are they called macro-nutrients?
Answer :

Macro-nutrients are the nutrients which are required by plants for its growth in large quantity. These nutrients are called as macro-nutrients. Eg. nitrogen, phosphorus, potassium, calcium, magnesium, sulphur .

Q. How do plants get nutrients?
Answer :

Plants get nutrients by three mediums air, water, soil. Their are 16 essential nutrients required by plants.

  • Air provides with oxygen and carbon
  • Water provides with hydrogen and oxygen
  • Rest out of 16 are provided by soli.
  • Q. Compare the use of manure and fertilizers in maintaining soil fertility.
    Answer :

    Q. 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.

    Q. Why should preventive measures and biological control methods be preferred for protecting crops?
    Answer :

    Over expose to 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.

    Q. What factors may be responsible for losses of grains during storage?
    Answer :

    Biotic and Abiotic factors are responsible for losses of grains during storage like: Rodents, pests, insects, fungi, bacteria, sunlight, flood, rain, temperature, moisture.

    Q. 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.

    Q. What management practices are common in dairy and poultry farming?
    Answer :

    Management practices which are common in dairy and poultry farming are:

    1. Well-designed Hygienic shelter for dairy animals and poultry birds.

    2. Good quality proper food and fodder are provided to dairy animals and poultry birds.

    3. Importance for animal health by prevention and cure of disease caused by bacteria, virus, or fungi.

    4. Sunlight feasible and airy ventilated shelter for animals

    Q. What are the differences between broilers and layers and in their management?
    Answer :

    Q. 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 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”.

    Q. How are fish obtained?
    Answer :

    Fishes are obtained in two ways:

    1. Capture fishing: obtaining fishes from natural resources.

    2. Culture Fishery: culturing of fishes in freshwater ecosystem like river, pond and lake also including marine.

    Q. What are the advantages of composite fish culture?
    Answer :

    Advantages of composite fish culture are:

    1.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.

    2. Food resource can be completely utilized.

    3. Survival of the fish also increases.

    4. More yield.

    Q. What are the desirable characters of bee varieties suitable for honey production?
    Answer :

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

    1. The variety of bee should yield large amount of honey.

    2. The bees should stay for a longer period in bee hives.

    3. The bees should not sting much.

    4. Bee should be disease resistant.

    Q. What is pasturage and how is it related to honey production?
    Answer :

    Pasturage refers to the availability of flowers to the bees for easy accessibility for pollen collection and nectar. Kinds of flowers available will determine the taste of the honey, hence Pasturage is the main reason for the good quality honey.