NCERT solutions Class 9 science Chapter 15: Improvement In Food Resources

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NCERT solutions for Class 9 science Chapter 15: Improvement In Food Resources  (updated)

In Text Question 1.1 Page number: 204

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

Ans:

Cereals are the source of carbohydrate and is main reason of energy.

Pulses provide protein for growth and development

Vegetables and fruits are loaded with minerals, vitamins, carbohydrates, proteins and fats for overall development.

In-Text Question 1.2  Page Number: 205

Q1. How do biotic and abiotic factors affect crop production?

Ans:

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.

Q2. What are the desirable agronomic characteristics for crop improvement?

Ans:

The essential agronomic features required for crop improvement are:

• Profuse branching along with tallness in any fodder crop
• Dwarfness in any cereals.

In Text Question 1.3 Page Number: 206

Q1. What are macro-nutrients and why are they called macronutrients?

Ans:

Macro-nutrients are the fundamental elements that are used by plants in more quantity. Macro-nutrients needed by the plants are:

• Macro-nutrients as the constituent of protoplasm

• Phosphorus, Nitrogen, Sulphur are present in proteins

• Calcium is existing in cell wall

• Magnesium is significant component of chlorophyll

Q2. How do plants get nutrients?

Ans:

There are 16 basic essential nutrients required by the plants to grow. Carbon and Oxygen are supplied by water and the remaining nutrients are supplied through soil.

In Text Question 1.4 Page Number: 207

Q1. Compare the use of manure and fertilizers in maintaining soil fertility.

Ans:

• 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.

In-Text Question 1.5  Page Number: 208

Q1. 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:

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.

In Text Question 1.6 Page Number: 209

Q1. Why should preventive measures and biological control methods be preferred for protecting crops?

Ans:

Over exposure 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.

Q2. What factors may be responsible for losses of grains during storage?

Ans:

Biotic and Abiotic factors are responsible for loss of grains during storage like:

• Rodents
• Pests
• Insects
• Fungi
• Bacteria
• Sunlight
• Flood
• Rain
• Temperature
• Moisture

In Text Question 1.7 Page Number: 210

Q1. Which method is commonly used for improving cattle breeds and why?

Ans:

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, care is taken to have a good resultant with high yield having resistance to climatic conditions.

In Text Question 1.8 Page Number: 211

Q1. What management practices are common in dairy and poultry farming?

Ans:

• Well-designed Hygienic shelter for dairy animals and poultry birds.
• Good quality proper food and fodder are provided to dairy animals and poultry birds.
• Importance for animal health by prevention and cure of disease caused by bacteria, virus, or fungi.
• Sunlight feasible and airy ventilated shelter for animals

Q2. What are the differences between broilers and layers and in their management?

Ans:

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.

Q3. 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:

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”.

In-Text Question 1.9 Page Number: 213

Q1. How are fish obtained?

Ans:

Fishes are obtained in two ways:

Capture fishing: obtaining fishes from natural resources

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

Q2. What are the advantages of composite fish culture?

Ans:

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

In Text Question 1.9 Page Number: 213

Q1. What are the desirable characters of bee varieties suitable for honey production?

Ans:

• The variety of bee should yield large amount of honey.
• The bees should stay for a longer period in bee hives
• The bees should not sting much.
• Bee should be disease resistant.

Q2. What is pasturage and how is it related to honey production?

Ans:

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 good quality honey.

Exercise Questions 1.1 Page Page Number: 214

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

Ans:

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?

Ans:

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 ?

Ans:

Inter-Cropping

• 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.

Crop-rotation

• 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.

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

Ans:

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.

Q5. How do storage grain losses occur?

Ans:

Storage grain losses occur due to various abiotic and biotic factors.

Abiotic factors:

• Humidity
• Air
• Temperature
• Flood
• Wind

Biotic factors

• Insects
• Rodent’s
• pesticides
• Bacteria
• Mites
• Birds

Q6. How do good animal husbandry practices benefit farmers?

Ans:

• Good practice of animal husbandry benefits farmers in the following ways:
• Yields in good quality cattle
• Better quality of milk production
• Use in agriculture for carting, irrigation and tilling

Q7. What are the benefits of cattle farming?

Ans:

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

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

Ans:

For increasing 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?

Ans:

Capture fishing: It is a technique in which fishes are captured from various sources of natural resources like sea, rives, lake and pond.

Mariculture: culturing of fish in marine fishes like prawns, oyster, bhetki and mullets in marine water for commercial use.

Aquaculture: Involved in culturing of fish in both marine and fresh water.

Solutions For NCERT Class 9 Science Chapter 15 Very Short Answer Type Questions

Question 1. Name any two fodder crops.
Answer:  Berseem, oats or sudan grass are raised as food for the livestock, called fodder crops.

Question 2. What do you understand b.y photoperiod of sunlight?
Answer: Photoperiod are related to the duration of sunlight required for plant growth.

Question 3. Name two kharif crops.
Answer: Paddy and soyabean.

Question 4. Name two rabi crops.
Answer:  Wheat and gram.

Question 5. Define hybridisation.
Answer: Hybridisation refers to crossing between genetically dissimilar plants, to obtain, better variety of crops.

Question 6. What are genetically modified crops?
Answer: By introducing a gene with required characters into a crop for its improvement is called genetically modified crop.

Question 7. “Shorter the duration of the crop from sowing to harvesting, the more economical is the variety”. Give reason for this.
Answer: Due to short duration of crop growth, farmers can grow more crops in a year, and reduce the cost of drop production.

Question 8. Name different types of crop production practices involved in India.
Answer: They are (a) no cost production, (b) low cost production and (c) high cost production.

Question 9. Who provides nutrients to plants?
Answer: Nutrients to plants are provided by air, water and soil.

Question 10. What are macro-nutrients?
Answer: The nutrients required by plants in larger quantity is called macro-nutrients. They are nitrogen, phosphorus, potassium, calcium, magnesium and sulphur.

Question 11. Name the nutrients that plant obtain from air and water.
Answer: Air – Carbon and oxygen Water- Hydrogen and oxygen

Question 12. State the difference between compost and vermi-compost.
Answer: The compost is obtained by decomposition of organic waste like animal excreta, plant waste etc. naturally due to decomposition by bacteria.
Vermi-compost: To hasten the process of decomposition redworms are added to this organic matter to obtain compost.

Question 13. Name any two weeds.
Answer: Parthenium and Xanthium.

Question 14. What causes disease in plants?
Answer:  It is caused by pathogens such as bacteria, fungi and viruses.

Question 15. Name two Indian cattle.
Answer: Bos indicus – cows 4 Bos bubalis – buffaloes

Question 16.  Name two exotic breeds of cattle.
Answer: Jersey and Brown Swiss

Question 17. Name two variety of food required for milch animals.
Answer:

• Maintenance requirement – food required to keep animal healthy
• Milk producing requirement – food required for increased lactation Animal food includes roughage and concentrate also.

Question 18.  State the meaning of capture fishing and culture fishing.
Answer: Capture fishing: It is done from natural resources.
Culture fishing: It is done by fish farming.

Question 19. Name four marine fish varieties.
Answer: Pomphret, mackerel, tuna and sardines.

Question 20. What is apiculture?
Answer: Keeping bee for obtaining honey commercially is called apiculture.

Question 21. Name the products obtained from apiculture.
Answer: Honey and wax both are obtained from apiculture.

Solutions For ncert Class 9 Science Chapter 15 Short Answer Type Questions

Question 1. What are the major group of activities involved for improvement of crop yields?
Answer:

• Crop variety improvement
• Crop production improvement
• Crop protection improvement

Question 2. What are the different ways/ methods of hybridisation?
Answer:  Hybridisation can be

• Intervarietal – between different varieties of crops
• Interspecific – between two species of same genus
• Intergeneric – between two different genera

Question 3. What are the main characters required in a crop during its improvement practices?
Answer: The useful characters that are required in a crop during its improvement:
(a) Disease resistance (b) Response to fertilizer
(c) Product quality and (d) High yield.

Question 4. State the difference between macro-nutrients and micro-nutrients.
Answer:

Question 5. How do deficiency of nutrients affect the crop?
Answer: Deficiency of any nutrient affects physiological processes in plants including reproduction, growth and susceptibility to diseases.

Question 6. State the difference between manure and fertilizer.
Answer:

Question 7. What are the harmful effects of fertilizer? .
Answer. It causes soil and water pollution. Continuous use can also destroy soil fertility.

Question 8. What is organic farming?
Answer: It is the farming in which no chemical fertilizers, pesticides or herbicides are used. But uses all organic matter for its growth like manure, neem leaves as pesticides and for grain storage.

Question 9. State the preventive and control measures used before grains are stored.
Answer:

• Cleaning of the grains
• Proper drying of the produce in sunlight, there should be no moisture.
• Fumigation of produce using chemicals that kills pest.

Question 10. Name few varieties of bees used for commercial honey production.
Answer:
Apis cerana indica – Indian bee
A. dorsata – rock bee (local varieties)
A. florae – the little bee
A. mellifera – Italian bee variety

Question 11. What decide the quantity and quality of honey production in apiary?
Answer: For quality of honey: The pasturage, f.e., the kind of flowers available to the bees for nectar and pollen collection will determine the taste of the honey. For quantity of honey: Variety of bee used for the collection of honey. For example, A. mellifera is used to increase yield of honey.

Question 12. How are crops useful to us? What do they provide?
Answer: Crops provide us food for our daily body nutrient. Carbohydrate for energy
requirement – Cereals such as wheat, rice, maize.
Protein for body building — Pulses like gram, lentil
Fats for energy — Oil seed like mustard, sunflower
Vitamins and minerals — From vegetables, spices and fruits
Fodder crops — For livestocks

Question 13. What are the factors for which variety improvement of crop is done?
Answer:
(a) Higher yield: It increases production of crop.
(b) Biotic and abiotic resistance: Crop should be resistant to biotic factors
like diseases, insects, pests and abiotic factor like drought, salinity, heat, cold, frost and water logging.
(c) Change in maturity duration: Short-duration maturity allows farmer to grow more crops in a year and reduces the cost of crop production.
(d) Wider adaptability: Crop’should be able to adapt to changing environmental conditions.
(e) Desirable agronomic characteristics: The tallness and dwarfness of crop. Dwarfness is required for cereals, so that less nutrients are consumed.

Question 14. Name the sources and the nutrients supplied by them to the plants.
Answer:

Question 15. What are manures? Give its classification.
Answer: Manures contain large ‘ quantities of organic matter and supplies small quantities of nutrients to the soil. It is prepared naturally by the decomposition of animal waste, excreta and plant waste.

• It helps in the soil enrichment with nutrients.
• It helps in improving the soil structure.
• It helps in increasing the water holding capacity in sandy soils.
• In clayey soils it helps in the water drainage and prevent water logging. Manure is classified based on the kind of biological material used to make it as : (i) Compost (ii) Vermi-compost (iitj Green manure
  (i) Compost: The farm waste and livestock excreta, along with vegetable waste, sewage waste, weeds, straws etc. are allowed to decompose in a pit is called compost. The compost is rich in nutrients.
  (ii) Vermi-compost: When the above given matter is allowed to decompose in the pit along with some earthworms, the decomposition speeds up and is called vermi-composting.
  (iii) Green manure: Some plants like sun-hemp or guar are grown and then mulched by ploughing them into the soil. This is done before the sowing of crop seeds into the field.
  These green plants present in the soil acts as green manure which enriches the soil in nitrogen and phosphorus.

Question 16. What are fertilizers? Excess use of fertilizers is not advisable, explain?
Answer: Fertilizers are obtained artificially on commercial basis. It is a chemical which contains the nutrients required for the crop to grow. Fertilizers supply various nutrients as they are nutrient specific e.g.-urea provides nitrogen. Mixed fertilizer provides any two mixture of nutrients. They are expensive but their use yield large production hence are a factor of high cost farming.
Excessive use of fertilizers are not advisable as:
(a) It leads to soil and water pollution.
(b) It can destroy the fertility of soil. As the soil is not replenished, micro¬organisms in the soil are harmed by fertilizers.

Question 17. What are the different patterns of cropping?
Or
What are the different cropping systems?
Answer:  Different ways/patterns / systems of growing crop’s are:
(a) Mixed cropping (b) Inter-cropping (c) Crop rotation.
Mixed cropping: It is a method in which two or more crops grow simultaneously on the same piece of land.
Example, Wheat + grain, wheat + mustard or groundnut + sunflower.
This helps in the reduction of risk factor and provides insurance against failure of one of the crops.
Inter-cropping: It is a method of growing two or more crops simultaneously on the same field in a definite patterns. A few row of one crop alternate with a few rows of second crop.
Example, soyabean + maize or bajra + lobia
Crop rotation: The growing of different crops on a piece of land in a pre¬planned succession is known as crop rotation.
The availability of moisture and irrigation facility decides the choice of crop to be cultivated after one harvest.

Question 18.  How does insect pests attack the plant and affect it?
Answer: Insect pests attack the plants in three ways:

1. They cut the root, stem and leaf.
2. They suck the cell sap from various parts of the plant.
3. They bore into stem and fruits.

This way they affect the health of the crop and reduces yield.

Question 19. Give different methods of weed control.
Answer: Weeds can be controlled by different methods:
(a) Weedicides: These are the chemicals sprayed on the weeds to kill them. Excessive use is poisonous and causes environmental pollution.
(b) Mechanical removal: In this method weeds are uprooted by removing manually or by machines.
(c) Preventive methods: Proper seed bed preparation, timely sowing of crops, intercropping and crop rotation helps in weed control.

Question 20. What are the new variety/traits obtained by cross breeding of Indian and exotic breeds of poultry?
Answer: The new variety/traits obtained by cross breeding of Indian and exotic breeds of poultry are:

1. Number and quality of chicks
2. Dwarf broiler parent for commercial chick production
3. Summer adaptation capacity/tolerance to high temperature
4. Low maintenance requirements
5. Reduction in the size of the egg-laying bird with ability to utilise more fibrous and cheaper diet, formulated using agricultural by-products