Gujarat Board Textbook Solutions Class 9 Science Chapter 15 Improvement in Food Resources

Gujarat Board Textbook Solutions Class 9 Science Chapter 15 Improvement in Food Resources

GSEB Solutions Class 9 Science Chapter 15 Improvement in Food Resources

Gujarat Board Class 9 Science Improvement in Food Resources Textbook Questions and Answers

Question 1.
Explain any one method of crop production which ensures high yield.
Answer:
Hybridization is one of the methods of crop production which ensures high yield. Hybridization refers to crossing between two genetically dissimilar plants each of which possesses a particular desired character. The two varieties are cross-bred during the process to incorporate both the desirable characteristics in a single variety.
The process of hybridization can be of following types:

• Intervarietal: crossing between different varieties.
• Interspecific: crossing between two different species of the same genus.
• Intergeneric: crossing between different genera.

Question 2.
Why are manure and fertilizers used in fields?
Answer:
The nutrients of the soil get depleted due to the continuous cultivation of crops. In order to replenish the nutrients of the soil, manures and fertilizers are added to the soil.

Question 3.
What are the advantages of Inter-cropping and crop rotation?
Answer:
In intercropping, two or more crops are simultaneously grown on the same field in a definite pattern.
This reduces the intraspecific competition among members of the same plant species. It helps to give better yield, ensure maximum utilization of the nutrients supplied, and prevent pests and diseases from spreading to all the plants belonging to one crop in a field.

In crop rotation, two or more crops are grown on a piece of land in a pre-planned succession. This method helps in replenishing the nutrients of the soil, increasing crop yield, control infestation by pests, and decrease the demand of nitrogenous fertilizers.

Question 4.
What is genetic manipulation? How is it useful in agricultural practices?
Answer:
The incorporation of desirable characteristics by hybridization, mutation, DNA recombination, polyploidy, etc., is called genetic manipulation. It is useful in agricultural practices as it helps in developing crop plants with desirable characteristics like higher yield, disease resistance, etc.

Question 5.
How do storage grain losses occur?
Answer:
The storage grain losses occur due to various factors which can be both biotic as well as abiotic. Biotic factors include insects, rodents, fungi, mites and bacteria, and abiotic factors are inappropriate moisture and temperatures in the place of storage.

These factors cause:

• degradation in quality
• loss in weight
• poor germinability
• discoloration of produce
• poor marketability

Question 6.
How do good animal husbandry practices benefit farmers?
Answer:
Animal husbandry is the scientific management of animal livestock. The good animal husbandry practices benefit farmers as:

• It helps to get better breeds of animals and ensure higher yield.
• It helps to keep the animals healthy and disease-free which reduces the input cost.

Question 7.
What are the benefits of cattle farming?
Answer:
Cattle farming iS done for two purposes:

• Dairy animals: They are kept for obtaining milk. Such animals are called animals. These include cow, buffalo, goat, etc.,
• Draught animals: They are used for transport and for farm labor, e.g., horses, bullocks, etc. Such animals are used for agricultural practices like tilling and irrigation.

Question 8.
For increasing production, what is common in poultry, fisheries, and bee-keeping?
Answer:
The selection of an improved variety of poultry, fishes and honeybees is common for increasing their production.

Question 9.
How do you differentiate between capture fishing, mariculture, and aquaculture?
Answer:
Fish are obtained from natural resources like rivers, sea, etc., in capture fishery. The culture of finned fishes like mullets, shellfish like prawns, mussels, oysters as well as seaweeds in marine water is called as mariculture. The practice of a culture of aquatic plants and aquatic animals for food in all types of water environments like lakes, ponds, rivers, oceans, etc., is called as aquaculture.

Gujarat Board Class 9 Science Improvement in Food Resources InText Questions and Answers

Page – 204

Question 1.
What do we get from cereals, pulses, fruits, and vegetables?
Answer:
We get the following from cereals, pulses, fruits and vegetables:
Cereals: Carbohydrates
Pulses: Proteins
Fruits and Vegetables: Vitamins and minerals. They also provide small amounts of carbohydrates,
proteins and oil.

Page – 205

Question 1.
How do biotic and abiotic factors affect crop production?
Answer:
Biotic factors like the diseases, insects and nematodes, and abiotic factors like drought, salinity, waterlogging, heat, cold, and frost result in a decrease in crop production i.e., the yield of crop.

Question 2.
What are the desirable agronomic characteristics for crop improvements?
Answer:
The desirable agronomic characteristics are required for increasing the yield of the crop. They differ from crop to crop. For example, the desirable characters for fodder crops are tallness and profuse branching. To develop cereals that consume fewer nutrients, awareness is a desirable character in them.

Page – 206

Question 1.
What are macronutrients and why are they called macronutrients?
Answer:
The nutrients can be classified on the basis of the amount in which they are required by the plants.
The nutrients which are required in large quantities are called macronutrients. For example, Nitrogen, phosphorus, potassium, etc.

Question 2.
How do plants get nutrients?
Answer:
A total of sixteen nutrients are required by plants. out of these, two nutrients, i.e., carbon and oxygen are obtained from air. One nutrient, hydrogen is obtained from water and the remaining thirteen elements are obtained by the plants from the soil.

Page – 207

Question 1.
Compare the use of manure and fertilizers in maintaining soil fertility.
Answer:
Manures contain large quantities of organic matter but are poor in the amount of nutrients when compared with the fertilizers. So, the cultivated field may get devoid of certain nutrients if only manures are used. The bulk of organic matter present in manure helps to increase the soil structure whereas the soil structure may get destroyed due to the use of fertilizers for long periods as they destroy the soil microorganisms that recycle the nutrients of the soil. Manures have a lot of organic matter which helps to absorb water into the soil whereas an excessive use of fertilizers results in water logging problems due to the lack of organic matter.

Page – 208

Question 1.
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 fertilizer.
(c) Farmers use quality seeds, adopt irrigation, use fertilizer, and use crop protection measures.
Answer:
The most beneficial condition will be a condition (c) because:

• Quality seeds will be helpful to get a higher yield.
• Proper irrigation will be helpful in providing water for the proper growth of the crop.
• The use of fertilizers will help in increasing the nutrient content of the soil and increase soil fertility.
• The use of crop protection measures will ensure that the crop does not get adversely affected by the weeds and the pests.
• This would prevent loss of crop and result in higher yields. Thus, the farmer will be able to get good quality produce and a higher yield with minimum or no loss of crop.

Page – 209

Question 1.
Why should preventive measures and biological control methods be preferred for protecting crops?
Answer:
Preventive measures and biological control methods should be preferred for protecting crops as they are environment-friendly approach. These methods do not pollute the environment whereas the chemical methods can cause a lot of environmental pollution.

Question 2.
What factors may be responsible for losses of grains during storage?
Answer:
The factors responsible for losses of grains during storage are:

• Biotic (living organisms) like insects, rodents, fungi, mites, bacteria, etc.
• Abiotic factors like inappropriate moisture and temperatures in the place of storage.

Page – 210

Question 1.
Which method is commonly used for improving cattle breeds and why?
Answer:
The method which is commonly used for improving cattle breeds is artificial insemination.
This is a very good method because:

• The semen collected from the bull can be frozen for long periods and can even be transported to distant places in a frozen state.
• The semen of a superior bull can be used to inseminate a large number of cows in order to obtain superior progeny in large numbers.

Page – 211

Question 1.
Discuss the implications of the following statement:
“R is interesting to note that poultry is India’s most efficient converter of low fiber foodstuff (which is unfit for human consumption) into highly nutritious animal protein food.”
Answer:
The statement implies that the poultry birds feed on the low fiber foodstuff which is unsuitable for human consumption and provide us with egg and meat which are a very rich source of proteins. Eggs and the meat (broiler) of the poultry birds fulfill the food requirements of a large number of people.

Page – 211

Question 1.
What management practices are common in dairy and poultry farming?
Answer:
The management practices common in the dairy and poultry farming are:

• Proper shelter for the animals with regular cleaning and hygienic conditions.
• Regular visits by a veterinary doctor.
• Feeding of animals in a scientific manner with good quality and quantity of feed.
• Selection of good quality of breed for the animals.
• Proper vaccination and record-keeping for the prevention of infectious diseases.
• Proper ventilation, light, temperature, etc., in the shelters.

Question 2.
What are the differences between broilers and layers and in their management?
Answer:
The meat-producing birds are called as broilers and the egg-laying birds are called layers. The housing, nutritional and environmental requirements of the broilers are different from the layers. The broilers are raised in poultry farms up to 6 – 7 weeks and usually weigh around 700 g to 1.5 kg. The requirement of the broilers is protein and fat-rich food.

The level of vitamin A and vitamin K is kept high in their feed. Care is taken to avoid mortality and to maintain the feathering and carcass quality. The layers start laying eggs at the age of 20 weeks. So, they are kept for longer periods of around 500 days, called laying period. They require enough space, proper light and hygienic conditions. Their feed consists of vitamins, minerals, and certain micronutrients which affect the hatchability of the eggs.

Page – 213

Question 1.
How are the fish obtained?
Answer:
The fishes are obtained by the following two ways:

• Capture fishery: Fishes are obtained from natural resources in capture fishery,
• Culture fishery: Fish farming is called culture fishery.

Question 2.
What are the advantages of composite fish culture?
Answer:
A combination of five or six fish species is used in a single fish pond in the composite fish culture system.
This is advantageous because:

• The selected species do not compete for food among them as they have different types of food habits.
• The food available in all the parts of the pond gets utilized.

Page – 213

Question 1.
What are the desirable characters of bee varieties suitable for honey production?
Answer:
Desirable characters of bee varieties suitable for honey production are:

• The higher yield of honey.
• Ability to protect from enemies and somewhat less stinging feature.
• Bees stay in a given beehive for long periods and breed very well.

Question 2.
What is pasturage and how is it related to honey production?
Answer:
Pasturage refers to the flowers available to the bees for nectar and pollen collection. The value or quality of honey depends upon the pasturage available for the collection of nectar.

In-Text Activities Solved

(Textbook Page 209)

Activity 15.1
Visit a weed-infested field in the month of July or August and make a list of the weeds and insect pests
in the field.
Answer:
A list of some weeds is given below. Students can find the names of other weeds.

1. Parthenium (Carrot grass)
2. Lantana camczra
3. Malvastrum coromandelianum
4.  Xanthium (Pokhran)
5. Amaranthus
6. Vicia sp.
7. Chenopodium album
8. Melilotus alba
9. Physalis angulata
10. Sesbania bispinosa
11. Solanum americanum
12. Ageratum conyzoides
13. Bidens pilosa
14. Catharanthus pusillus
15. Crotalaria retusa
16. Datura innoxia.

(Textbook Page 209)

Activity 15.2
Make a herbarium of cereals, pulses, and oilseeds and identify the seasons of their sowing and harvesting.
Answer:
Do it yourself.

(Textbook Page 210)

Activity 15.3
Visit a livestock farm. Note the following:
1. Number of cattle and number of different breeds.
2. The amount of daily milk production from the different breeds.
Answer:
Do it yourself.

(Textbook Page 211)

Activity 15.4
Visit a local poultry farm. Observe types of breeds and note the type of ration, housing and lighting
facilities given to them. Identify the growers, layers and broilers.
Answer:
Do it yourself.
Types of breeds: Rhode island red, Aseel, White leghorn, etc.
Type of ration, housing and lighting facilities: Do it yourself
Refer site:
http://agritech.tnau .ac.in/animal_husbandry/ani_chikjrower&layer%2Omgt.html
Identify the growers, layers and broilers-Refer sit& https://en.wikipedia.org/wikilPoultry_farming and other such websites.

(Textbook Page 213)

Activity 15.5
Visit a fish farm in fish breeding season and note the following:

1.  Varieties of fish in the ponds
2. Types of ponds
3. Feed ingredients being used in the farm
4. Find out what the production capacity of the farm is.

Answer:
Do it yourself.

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