P S VERMA AND V K AGARWAL Solutions for Class 9 Biology Chapter 1 - Improvements In Food Resources

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Chapter 1 - Improvements In Food Resources Exercise 63

Question 1

Distinguish between micronutrients and macronutrients. Give suitable examples.

Solution 1

Micronutrients

Macronutrients

(i) They are required in very small quantities.

(ii) They are involved in enzyme activity and electron transport.

Example - Iron, Zinc

(i) They are required in large quantities.

(ii) They have no significant role in enzyme activity and electron transport.

Example - Nitrogen, Calcium

Question 2

Classify nutrients according to their sources.

Solution 2

Source

Nutrients

(i) Air

Carbon (C)

Oxygen (O)

Hydrogen (H)

(ii) Water

Nitrogen (N)

Phosphorus (P)

Potassium (K)

Calcium (Ca)

Magnesium (Mg)

Sulphur (S)

(iii) Soil

Iron (Fe)

Manganese (Mn)

Boron (B)

Zinc (Zn)

Copper (Cu)

Molybdenum (Mo)

Chlorine (Cl)

Question 3

How plants get nutrients?

Solution 3

Plants get nutrients through air, water and soil.

Question 4

Name three most important nutrients required for plant growth.

Solution 4

Nitrogen, phosphorus and potassium.

Question 5

Chose plant's micronutrients and macronutrients from the following

Iron, Chlorine, Sulphur, Copper, Nitrogen, Calcium, Manganese, Potassium, Zinc, Molybdenum, Phosphorus.

Solution 5

Iron - Micronutrients.

Chlorine - Micronutrients.

Sulphur - Macronutrients.

Copper - Micronutrients.

Nitrogen- Macronutrients.

Calcium- Macronutrients.

Manganese- Micronutrients.

Potassium- Macronutrients.

Zinc- Micronutrients.

Magnesium- Macronutrients.

Molybdenum- Micronutrients.

Phosphorus- Macronutrients.

Question 6

What are advantages of using manure?

Solution 6

Advantages of manures are:

(i) Manures are natural fertilizers.

(ii) Manures are bulky sources of organic matter which supply nutrients in small quantity and organic matter in large quantities.

Question 7

Give two limitations of using manure.

Solution 7

Limitations of using manures are:

(i) Manures are not nutrient specific.

(ii) Manures are not able to fulfill the high and rapid demand of nutrients required by improved high-yielding hybrid varieties of crops.

Question 8

Compare the use of manures and fertilizers in maintaining soil fertility.

Solution 8

Manure contains many organic substances of biological origin which can be easily degraded and absorbed by plants. It helps in recycling of biological waste. Manures increase the fertility of soil for long duration without causing any harm. However, the chemical fertilizers (e.g. urea) improve soil fertility for short duration but cause environmental hazard. Continuous use of fertilizers in a particular area / crop field causes destruction of soil fertility.

Question 9

Write down two advantages of fertilizer over manure.

Solution 9

Advantages of fertilizer over manure:

(i) Fertilizers are very rich in plant nutrient whereas manure contains small amounts of essential plant nutrients.

(ii) Fertilizers are soluble in water whereas manure is not soluble in water.

Question 10

During the downpour in a village, the rain water carried away excess of nitrogenous and other compounds present in the soil to pond. How will they affect the growth of algae and phytoplankton in the pond?

Solution 10

As a result of this, the pond water would acquire a high concentration of nitrates and phosphates which would result in the excessive growth of algae and phytoplankton in the pond.

Question 11

Explain the term eutrophication with suitable example.

Solution 11

Eutrophication is a process whereby water bodies, such as lakes or slow-moving streams receive excess nutrients that stimulate excessive plant growth (algae, phytoplankton's and nuisance plants weeds). This enhanced plant growth is also termed as an algal bloom.

Example: During rains the nutrients from the fields are washed away and get accumulated in nearby water bodies.

Question 12

How does chemical nature of the soil change due to continued use of chemical fertilizers ?

Solution 12

The continuous use of chemical fertilizers in a particular area or crop field leads to loss of soil fertility.

Question 13

Explain various methods of fertilizer application. Classify fertilizers.

Solution 13

There are three methods of fertilizer applications in practice:

(i) Broadcasting: Uniform distribution over the whole cropped field.

(ii) Placement: Application in bands or in pockets near the plants or plant rows.

(iii) Foliar application: Using low or high volume sprayers, the fertilizers are sprayed covering the plants.

Question 14
Distinguish between farmyard manure and compost manure.
Solution 14
Farmyard Manure Compost Manure
It is the decomposed mixture of cattle excreta, dung, urine, litter and left over organism matter such as roughage and Fodder. It is prepared from farm and town refuge such as vegetable and animal refuse.
Question 15

Define manure. What are different manures and how do they affect the soil?

Solution 15

Manure - Manures are natural fertilizers. They are bulky sources of organic matter which supply nutrients in small quantities, and organic matter in large quantities. There are different types of manures: Farmyard manure (FYM), Compost, Green manures and Vermicompost.

Manures affect the soil in following three ways:

(i) Manures enrich the soil with nutrients. They replenish the general deficiency of nutrients in the soil. Since manure contains fewer nutrients they need to be used in large quantities.

(ii) Manures add organic matter (called humus) to the soil which restores the soil texture, for better retention of water and aeration of soil.

(iii) The organic matter in manures provides food for the soil organisms, (decomposers such as bacteria, fungi, etc. which help in providing nutrients to plants.

Question 16

What is green manuring? Give suitable examples for green manures.

Solution 16

Green manuring is the practice which includes growing, mulching by ploughing and mixing of green crops with soil, to improve physical structure and soil fertility.

Example - Sunn hemp (Crotalaria juncea).

Question 17

What are fertilizers? Classify fertilizers.

Solution 17

Fertilizers - Fertilizers are one of the major components for obtaining higher yields especially in expensive farming practices. Fertilizers are divided into following four groups:

(i) Nitrogenous fertilizers - These fertilizers supply the macronutrient nitrogen.

Example - Urea, CO(NH2)2

(ii) Potassic fertilizers - These fertilizers supply potassium which is one of the essential macronutrient of the plants.

Example - Potassium sulphate, K2SO4.

(iii) Complex fertilizers - These fertilizers contains two or more nutrients.

Example - Nitrophosphate

Question 18

Give a short account of biofertilizers.

Solution 18

Biofertilisers - Organisms which enrich the soil with nutrients are called biofertilisers. Biofertilisers are used for the specific crop plants such as pulses, legumes, oil seeds and rice. They are renewable and non-pollutant sources of plant nutrient such as nitrogen.

Nitrogen fixing microorganisms, i.e., non-symbiotic and symbiotic cyanobacteria and phosphate-solubilising microorganism are the main type of biofertilisers.

Question 19

Explain why a legume crop does not require nitrogenous fertilizers?

Solution 19

A legume crop does not require nitrogenous fertilizers because its roots have root nodules which have nitrogenous bacteria called Rhizobium. This bacteria fixes atmospheric nitrogen and the plants converts nitrogen into various nitrogenous compounds.

Question 20

Why is irrigation essential?

Solution 20

Irrigation is essential for the absorption of nutrient elements by the crop plants from the soil. The irrigation water tends to dissolve the nutrients present in the soil of a crop field to form a solution. This solution of nutrients is then absorbed by the roots of crops for the development of the plants.

Question 21

How does excessive irrigation lead to soil salinity?

Solution 21

Excessive irrigation causes water logging and increases surface salinity which leads to soil salinity.

Question 22

Mention three effects of excessive irrigation.

Solution 22

Effects of excessive irrigation:

(i) It causes water logging.

(ii) It increases salinity in the soil.

(iii) The roots do not get proper aeration due to which they die.

Question 23

Why water should be used judiciously?

Solution 23

Water should be used judiciously because:

(i) It helps in the cultivation of crops.

(ii) In desert areas where there is scarcity of water, it is supplied through irrigation practices to prevent drought.

Question 24

Explain advantage of irrigation.

Solution 24

Advantages of irrigation:

(i) It is necessary to provide sufficient moisture for the germination of seeds.

(ii) Irrigation of crop plants is essential for the growth and elongation of roots of the crop plants.

(iii) It is necessary to increase the number of aerial branches in crop plants.

(iv)It is essential for the absorption of nutrient elements by the crop plants from the soil.

Question 25

Explain, how efficiency of irrigation can be increased.

Solution 25

The efficiency of irrigation can be increased by:

(i) Drip and sprinkler system - It increases the efficiency of irrigation as it sprays water through pipes and a sprinkler.

(ii) River lift system - It is useful in those areas where canal flow is insufficient or irregular due to inadequate water release. The water is directly drawn from the rivers for supplement irrigation.

Question 26

Explain the various factors which are responsible for the loss of stored food grains.

Solution 26

There are two main factors responsible for loss of grains during storage:

(i) Biotic factors - Insects, rodents, birds, mites and bacteria.

(ii) Abiotic factors - They include moisture, temperature and other non-living environmental factors.

Question 27

Explain the various preventive measures which are taken before storing the food grains.

Solution 27

Biotic and abiotic factors which cause destruction of grains during storage can be prevented by the following methods:

(i) Drying - The harvested food grains should be dried by spreading them over plastic sheets or cemented floors. All the sun dried food grains are allowed to cool to room temperature before storing them.

(ii) Cleaning - The grains should be properly cleaned before storage. They should be filled in new gunny bags before keeping in godowns, warehouses or stores.

Question 28

Describe how drying of food grains is done.

Solution 28

Drying - The harvested food grains is dried by spreading them over plastic sheets or cemented floors. All the sun dried food grains are then allowed to cool to room temperature before storing them.

Question 29

Write down three unique characteristics of storage structure.

Solution 29

For the storage of grains, grain silos are used. The silos are big and tall cylindrical structures. They are provided with outlets at different levels to withdraw the desired stock of grains. They have built in arrangement for aeration, temperature control, protection from insects, rats, birds etc.

Question 30

Describe the various methods of controlling pests attacking stored grains.

Solution 30

Field crops are infested with a variety of pests. There are various methods by which insects and diseases can be controlled. One of the most common and effective methods is the use of pesticides or biocides which include insecticides (for killing the insects), weedicides (for killing the weeds) and fungicides (for killing the fungi). Thus chemicals used to kill the pests, e.g. weeds; insects, mites, rodents and fungi are called pesticides. These chemicals are sprayed on crop plants or used for treating seeds and soil.

Question 31

As an incharge of a grain store, how will you find out the presence of pests?

Solution 31

During the grain storage, if the loss is due to the biotic factors which includes insects, rodents, birds, mites, fungi and bacteria, then it shows the presence of pests in the grain stores.

Question 32

How does fumigation differ from spraying?

Solution 32

Spraying

Fumigation

(i) Spraying requires mechanical devices such as manual sprayer or mechanical sprayer.

(ii) It is less effective than fumigation.

(i) It does not require any mechanical device.

(ii) It is more effective than spraying.

Question 33

Milk is a very nutritious food'. Use the table given in the book to justify statement.

Solution 33

Milk is rich in fat, tocopherol, proteins, calcium, and phosphorus and contains low sodium, potassium and cholesterol. It is ideal for making milk products like ghee, curd etc. Milk in comparison to other food products such as egg and meat contain all the major food constituents such as carbohydrates, proteins, fats, minerals, water and vitamins such as A and D.

Question 34

Name four animals which provide us food.

Solution 34

The animals which provide us food are cow, buffalo, hen and fish.

Question 35

Write down the names of animal products which are used as food.

Solution 35

Animal products used as food are: Milk, egg, meat, honey.

Question 36

How does roughage differ from concentrates ith reference to cattle feed?

Solution 36

Roughage

Concentrates

(i) Roughage contains fibres such as green fodder, silage, hay and legumes.

(ii) It is high in fibre.

(i) Concentrates are a mixture of substances which are rich in one or more nutrients.

(ii) It is low in fibre.

 

Question 37

Give an example of average daily feed of cow.

Solution 37

The daily average feed of a cow is given below:

(i) Green fodder and dry grasses (roughage) = 15 to 20 Kg.

(ii) Grain mixture (Concentrates) = 4 to 5 Kg.

(iii) Water = 30 to 35 litres.

Question 38

What are the sources of "concentrates" given in a cattle feed ?

Solution 38

The sources of concentrates are cotton seeds, oil seeds, grains of maize, oats, barley, jowar, bajra, gram and their by products such as wheat bran, rice bran, gram husk, oil seed cakes and molasses.

Question 39

Write down four main characteristics of good cattle shelter.

Solution 39

(i) The shelters should have roofed sheds which protects them from rain, heat, direct sunlight and cold.

(ii) The floor of cattle shed is made brick-lined and sloping for faciliating cleaning and keeping their sitting place dry.

(iii) The sheds or shelters should be provided with cross ventilation with sufficient number of inlets and outlets.

(iv) The shelters are provided with feeding passage and feeding trough.

Chapter 1 - Improvements In Food Resources Exercise 64

Question SAQ - 11
Explain various steps in hybridization of crop plants.
Solution SAQ - 11
The three steps involved in hybridization are:

(i) Introduction - This refers to the transportation of crop plants from the place of cultivation to the place where they were grown earlier.

(ii) Selection - This process involves the selection of most desirable offspring of a variety of plant for controlled propagation.

(iii) Hybridisation - It involves the crossing between genetically dissimilar plants to produce a new kind. Crossing may be between two different varieties (intervarietal cross - breeding) or between the two different species of the same genus (inter specific cross - breeding) and between different genera (intergeneric cross - breeding).
Question SAQ - 12
Define plant breeding? Describe the various methods of plant breeding.
Solution SAQ - 12
Plant breeding means production of new varieties or strains by a programme of artificial selection spanning several generations of the organism concerned.

It involves hybridization and mutation breeding.

(i) Hybridisation - It involves the crossing between genetically dissimilar plants to produce a new kind. Crossing may be between two different varieties (intervarietal cross - breeding) or between the two different species of the same genus (inter specific cross - breeding) and between different genera (intergeneric cross - breeding).

(ii) Mutation breeding - The breeding that takes place through various mutagens.
Question SAQ - 13
Describe the biological method of weed control.
Solution SAQ - 13
Biological method of weed control involves the deliberate use of insects or some other organisms which consume and specifically destroy the weed plants.

Example - Opuntia can be controlled by using cochineal insects in Maharashtra.
Question SAQ - 14
Classify plant diseases depending upon their occurrence and transmission.
Solution SAQ - 14
Plant disease Occurrence Transmission
(i) Blast

(ii) Rust

(iii) Wilt

(iv) Stem rot

(v) White rust
Rice

Wheat

Chick pea

Pigeon pea

Mustard
Air-borne

Air-borne

Soil-borne

Water-borne

Air-borne
Question SAQ - 15
Mention three different ways in which insect pests can attack the crop plant.
Solution SAQ - 15
The ways by which the insects attack the crop plants are:

(i) The chewing insects destroy all sorts of crop plants. They cut the root, stem and leaf of the crop plants by the help of their chewing mouth parts.

(ii) Sucking insects suck the cell sap from various parts of the plant. They make fine punctures in the skin of plants with their needle - like, hollow beaks and suck the sap.

(iii) The internal feeders live inside the plant parts. They make holes in the developing grains.
Question SAQ - 16
Explain the methods of controlling insect pests.
Solution SAQ - 16
Controlling insect pests:

(i) Root cutting type of insects is controlled by mixing insecticides in the soil.

Example - Chloropyriphos.

(ii) Stem and leaf cutting type of insects can be controlled by dusting or spraying the contact insecticides.

Example - Malathion, lindane and thiodan.

(iii) All sap sucking insects can be controlled by spraying systematic insecticides.

Example - Dimethoate and metasystox.
Question SAQ - 17
Give two examples each of

(a) Narrow leaved rabi season weed.

(b) Broad leaved kharif season weed.
Solution SAQ - 17
(a) Example of narrow leaved rabi season weeds are - Cyperus rotundas and Wild sorghum.

(b) Example of broad leaved kharif season weeds are - Amaranthus viridis and Trianthema.
Question SAQ - 18
Explain various methods of weed control.
Solution SAQ - 18
The various methods of weed control are:

(i) Mechanical methods - These include uprooting, weeding with trowel or khurpi, hand hoeing, interculture, ploughing, burning and flooding.

(ii) Cultural methods - This includes the proper bed preparation, timely sowing of crops, intercropping and crop rotation.

(iii) Chemical methods - Herbicides and weedicides are sprayed on weeds to destroy weeds like - 2, 4 - D.

(iv) Biological methods - Biological method of weed control involves the deliberate use of insects or some other organisms which consume and specifically destroy the weed plants. Example - Opuntia can be controlled by using cochineal insects in Maharashtra.
Question SAQ - 19
Explain various effects of weeds on crop plants.
Solution SAQ - 19
Effect of weeds on crop plants:

(i) The growth of weeds in the crop fields is harmful because they compete with the crops for nutrients, water, space and light.

(ii) The weeds spread crop pests and diseases by acting as alternate host to insects and microorganisms.

(iii) Some weeds may produce toxic substances which may interfere with the growth of crop plants.

(iv) During harvesting weeds get mixed with crop's produce to downgrade its quality.
Question SAQ - 20
What are crop's pests? Suggest preventive measures to control pests.
Solution SAQ - 20
Crop's pest is any destructive organism which causes great economic loss by destroying crop plants or products obtained from them.

These can be controlled by the use of pesticides or biocides which includes insecticides, weedicides and fungicides. These chemicals are sprayed on crop plants or used for treating seeds and soil.
Question SAQ - 21
What is the advantage of using insect resistant varieties?
Solution SAQ - 21
Insect resistant varieties are advantageous as they do not get infested with pests. Their genes are modified so pests cannot harm them. Therefore, pesticides are not used to protect them diseases which are toxic in nature and cause environmental pollution.
Question LAQ - 1

Distinguish between fertilizer and manure. Give suitable examples. What are advantages and disadvantages of using fertilizer?

Solution LAQ - 1

Manures

Fertilizers

(i) They are organic in nature.

(ii) They are generally insoluble in water.

(iii) They are not nutrient specific.

(iv) They are biodegradable.

(v) They are voluminous and bulky, so difficult to store and carry.

(vi) They provide humus to the soil.

Examples - compost and green manure.

(i) They are inorganic in nature.

(ii) They are generally soluble in water.

(iii) They are nutrient specific.

(iv) They are non-biodegradable.

(v) They can be easily stored and are easy to carry.

(vi) They do not provide humus to the soil.

Examples - urea and ammonium sulphate.

Advantages of Fertilizers:

(i) They are easy to store, transport and apply to crops.

(ii) Being soluble in water, they are readily absorbed by the crop plants.

(iii) They are nutrient specific and can be selected according to the specific nature of the soil.

Disadvantages of Fertilizers:

(i) They are costly.

(ii) These are the chemicals, which when washed away with rain water, pollute the water bodies.

Question LAQ - 2

Explain the mechanism of compost formation.

Solution LAQ - 2

Mechanism of compost formation:

(i) A trench of dimension of 4 to 5 m long, 1.5 to 1.8 m broad and 1.0 to 1.8 m deep is dug.

(ii) A layer of well mixed refuse of about 30 cm thickness is spread in the trench.

(iii) The refuse layer is well moistened by slurry of cow dung, earth and water.

(iv) Now, a second layer of well mixed refuse is spread in trench till the heap rises to a height of 45 to 60 cm above the ground level.

(v) The top of the heap is covered with a thin layer of moist earth.

(vi) After three months, the material is taken out of the trench and placed in the form of conical heap. The conical heap, if required, be suitably moistened and should be covered with earth.

(vii) Conical heap is left undisturbed for about one to two months. After this period, compost can be used in crop fields.

Question LAQ - 3

Explain what will happen if in a cultivated field only manures are supplied and in another field only fertilizers are supplied, keeping all other conditions similar.

Solution LAQ - 3

Manures are rich in organic matter but are poor supplier of nutrients. So, the cultivated field which is not supplied with fertilizers may suffer from the deficiency of nutrients and not give very good yield.

The cultivated field which is supplied with fertilizers only may face drainage problem and water logging due to lack of organic matter in the soil. This may harm the crop and the yield. Use of fertilizers over long periods of time can destroy the soil texture by killing the microorganisms that recycle nutrients in the soil.

Question LAQ - 4

Define irrigation. Why is irrigation of crops essential? Mention the harmful effects of excessive irrigation.

Solution LAQ - 4

Irrigation is the process of supplying water to crop plants by means of canals, wells, reservoirs, tube-wells, etc.

Irrigation is necessary in the areas where there is scarcity and irregular distribution of rain that can cause drought. It provides sufficient moisture for the germination of seeds, as seeds do not germinate in dry soil. It is also necessary for the growth and development of crop plants. The irrigation water tends to dissolve the nutrients present in the soil and forms a solution which is easily absorbed by the roots of the plants.

Excessive irrigation causes water logging and increases surface salinity. In water logged soil, plants do not get proper aeration.

Question LAQ - 5
Explain various types of irrigation system in India. How can efficiency of applied water be increased in agriculture.
Solution LAQ - 5

The various types of irrigation systems are -

(i) Canal system: In this system, the human-made canals receive water from one or two reservoirs or from rivers. The main canal is distributed into branch canals which have further distributaries or field channels.

(ii) Tanks: These are small storage reservoirs which catch and store the runoff of smaller catchment areas.

(iii) Wells: These are of two types - dug wells and tube wells. In dug wells, water is collected from water bearing strata. The water from the shallow strata slowly accumulates in the pit and water is lifted by mechanical means. A tube well can tap water from the deeper strata.

(iv) River lift system: It is more useful in the areas where canal flow is insufficient or irregular due to inadequate water release. In this system, water is directly drawn from the rivers for supplement irrigation.

(v) River valley system: Certain parts of the country such as Karnataka and Kerala which lie along the Western Ghats use water that is discharged into the steep and narrow riverine valleys, during the rainy season. The bottom flat lands of the valleys are used for growing crops.

(vi) Drip and sprinkler system: It employs the overhead pipes for spraying water.

Efficiency of applied water can be increased by rain water harvesting and water shed management.

Question LAQ - 6

Compare between mixed cropping and intercropping. Write down from advantage of both of these techniques.

Solution LAQ - 6

Mixed Cropping

Intercropping

(i) It aims to minimize the risk of crop failure.

(ii) Seeds of two crops are mixed before sowing.

(iii) It involves no set pattern of rows of crops.

(iv) Spraying for pest control to individual crop is difficult.

(i) It aims to increase the productivity per unit area.

(ii) Seeds of two crops are not mixed.

(iii) It involves set pattern of rows of crops.

(iv) Pesticides can be easily applied to individual crop.

Advantages of mixed cropping:

(i) The risk of total crop failure due to uncertain monsoon is reduced.

(ii) Chances of pest infestation are greatly reduced.

(iii) Fertility of the soil is improved by growing two crops simultaneously.

Advantages of intercropping:

(i) It makes better use of the natural resources of sunlight, land and water.

(ii) Soil erosion is effectively arrested.

(iii) The produce of each crop can be marketed and consumed separately.

Question LAQ - 7

Explain the various methods of crop improvement.Name one improved variety of Rice, Maize, Soyabean,Sunflower and Mustard.

Solution LAQ - 7

Crop variety improvement is the manipulation of crop plants for increasing their yield and improving quality. Various approaches which are used for genetic improvement of crop plants are referred as plant breeding methods. These involve three processes:

(i) Introduction - This refers to the transportation of crop plants from the place of cultivation to the place where grown earlier.

(ii) Selection - This process involves the selection of most desirable offspring of a variety of plant for controlled propagation.

(iii) Hybridisation - It involves the crossing between genetically dissimilar plants to produce a new kind. Crossing may be between two different varieties (intervarietal cross - breeding) or between the two different species of the same genus (inter specific cross - breeding) and between different genera (intergeneric cross - breeding).

Crop

Improved Variety

Rice

Maize

Soyabean

Sunflower

Mustard

IR8

Ganga 5

PK 262

BSH 1

Pusa Bold

Question LAQ - 8

Discuss the various methods which are used to control plant diseases.

Solution LAQ - 8

Methods to control plant diseases:

(i) Seed treatment with Thiram 2.5 g/kg to prevent blast of rice.

(ii) Spraying Bavistin at 10 days interval to prevent wheat rust.

(iii) Spraying Dithane M45 at 2 g/l water at 10 days interval to prevent wheat rust.

(iv) Avoid water logging for fungus diseases.

(v) Growing sorghum and pigeon pea mixed cropping to avoid stem rot.

(vi) Spraying the crop with 0.2% Ziram and Maneb.

Question LAQ - 9

Explain the various preventive measures against insect pests.

Solution LAQ - 9

Preventive measures against insect pests:

(i) Root cutting type of insects is controlled by mixing insecticides in the soil.

Example - chloropyriphos.

(ii) Stem and leaf cutting type of insects can be controlled by dusting or spraying the contact insecticides.

Example - malathion, lindane and thiodan.

(iii) All sap sucking insects can be controlled by spraying systematic insecticides.

Example - dimethoate and metasystox.

Question LAQ - 10

What is feed? What are different type of feed? How is it differ with respect to age and functions?

Solution LAQ - 10

The food eaten by animals is called feed.

The animal feed is of two types:

(i) Roughage - It largely contains fibres such as green fodder, silage, hay and legumes.

(ii) Concentrates - It includes the mixture of substances which are rich in one or more nutrients. Concentrates are low in fibres and contains relatively high proteins and other nutrients. Example - oil seeds, cotton seeds, oats, barley, jowar, gram etc.

Feed according to age and functions are:

(i) Maintenance requirements - The food is required by the animal to support it to perform the basic functions of life.

(ii) Milk producing requirements - It includes the type of food during lactation period. Maintenance part of the ration depends upon the body weight and age while milk production part is dependent upon the level and composition of milk.

Question SAQ - 1
Write notes on plants and animals as sources of food.
Solution SAQ - 1
Plants as food are gift of nature to humans and most animals. Different parts of plants, such as root, stem, leaf, flower and fruit are consumed by humans in the form of cereals, vegetables, spices and fruits. Animals produce milk, egg, meat, etc. which also supplement our food requirements.
Question SAQ - 2
Define green revolution, what are the common objectives of crop improvement?
Solution SAQ - 2

Green revolution is the high production of food grains. The objectives of crop improvement are:

(i) Crop production management.
(ii) Crop variety improvement.
(iii) Crop protection management.

Question SAQ - 3
What we do get from cereals, pulses, fruits and vegetables?
Solution SAQ - 3
The cereals provide us with carbohydrates. The pulses provide us with proteins. Fruits and vegetables give us carbohydrates, protein, fat, vitamins, minerals and lots of fibers.
Question SAQ - 4
Explain the objectives of mixed cropping. How are crop selected for mixed cropping.
Solution SAQ - 4
The basic objective of mixed cropping is to minimize the risk and insure against the crop failure due to abnormal conditions.

Criteria for the selection of crops for mixed cropping:

(i) The different crops to be grown together are so selected that the products and waste materials from one crop stimulates the growth of the other crop.

(ii) Care is taken to select crops that do not compete with each other for light, nutrients and water.
Question SAQ - 5
Distinguish between mixed cropping and intercropping.
Solution SAQ - 5
Mixed Cropping Intercropping
(i) It aims to minimize the risk of crop failure.

(ii) Seeds of two crops are mixed before sowing.

(iii) It involves no set pattern of rows of crops.
(i) It aims to increase the productivity per unit area.

(ii) Seeds of two crops are not mixed.

(iii) It involves set pattern of rows of crops.
Question SAQ - 6
Explain the advantages and disadvantages of mixed cropping.
Solution SAQ - 6
Advantages of mixed cropping:

(i) The risk of total crop failure due to uncertain monsoon is reduced.

(ii) Chances of pest infestation are greatly reduced.

(iii) Fertility of the soil is improved by growing two crops simultaneously.

Disadvantages of mixed cropping:

(i) Seeds of two crops are mixed before sowing and there is no definite pattern for sowing the seeds.

(ii) Products of different crops are harvested, threshed, marketed and consumed in mixed form.
Question SAQ - 7
Define intercropping. How does it differ with mixed cropping?
Solution SAQ - 7
Intercropping is the practice of growing two or more crops simultaneously in a same field in definite row patterns with the objective of increasing productivity per unit area.

Mixed Cropping Intercropping
(i) It aims to minimize the risk of crop failure.

(ii) Seeds of two crops are mixed before sowing.

(iii) It involves no set pattern of rows of crops.
(i) It aims to increase the productivity per unit area.

(ii) Seeds of two crops are not mixed.

(iii) It involves set pattern of rows of crops.
Question SAQ - 8
Write down disadvantages of crop rotation.
Solution SAQ - 8
Disadvantages of crop rotation: Crops of the same family should not be repeatedly grown in the same field. This practice will promote build up of diseases and insect pests and decrease the similar nutrients from the soil.
Question SAQ - 9
Write about three main criteria which should be considered while selecting the crops for rotation?
Solution SAQ - 9
Criteria for the selection of crops for crop rotation:

(i) Availability of moisture through rain or irrigation.

(ii) Status of nutrients in the soil.

(iii) Duration of crop - short or long.
Question SAQ - 10
Why are leguminous crops desirable in crop rotation?
Solution SAQ - 10
Leguminous crops are required in crop rotation as they are used to increase the soil fertility. Those crops which require high fertility level may be grown after growing legumes. They also replenish the soil with nitrogen content.
Question 40
Which method will you suggest for improving the cattle breed and why?
Solution 40
Artificial insemination; It generally gives improved breeds. This method is widely used to improve the qualities of cow, buffaloes, poultry, horse, sheep, goats and pigs. This method is economical, reliable and hygienic.
Question 41
Write short notes on:

(a) General utility breeds of cow.

(b) Breeds of buffalo.
Solution 41
(a) Cows are classified as draught, diary and dual purpose breeds.

(i) Draught breeds - Their meat is tough and gives little milk. They are used in agricultural practices.

(ii) Diary breeds - They have large digestive systems and gives large amount of milk.

(iii) Dual breeds - These breeds provide milk as well as help in agricultural tasks.

(b) Breeds of buffaloes - There are ten breeds of buffalo in our country. The important breeds of buffalo with high yield of milk are - Murrah, Mehsana and Surti.
Question 42
Mention four steps involved in artificial insemination.
Solution 42
Steps involved in artificial insemination are:

(i) The semen of healthy and tough animal of high milk yielding breed is collected.

(ii) It is preserved by freezing or chemical methods.

(iii) The preserved semen is then injected into the genital tract of the female animal.

(iv) The preserved semen is injected during fertility period.
Question 43
Define artificial insemination. Write down two advantages on it.
Solution 43
Artificial insemination is the process of injecting the semen obtained from a desired male bull of high milk yielding breed into the genital or reproductive tract of female animal during heat period.

Advantages:

(i) It is economical because semen from a single bull can be used to impregnate several thousand cows.

(ii) It gives high rate of successful fertilization.
Question 44
Write down four symptoms of sick animals.
Solution 44
Symptoms of sick animals:

(i) Fever

(ii) Constipation followed by severe diarrhea.

(iii) Restlessness

(iv) Irritation

Question 45
Write the characteristic symptoms of:

(a) Mastitis

(b) Foot-and-mouth disease
Solution 45
(a) Symptoms of Mastitis: Fever, udder becomes swollen, milk is watery.

(b) Symptoms of Foot-and-mouth: Blisters appear on the mouth and foot resulting in extreme soreness of the parts. Loss of appetite, excessive salivation, high fever accompanied by shivering and inability to work.
Question 46
How are high yielding breeds of poultry advantageous over indigenous breeds?
Solution 46
The high yielding breeds of poultry are advantageous over indigenous breeds as:

(i) Improved quality and quantity of chicks.

(ii) Low maintenance requirement.

(iii) Improvement in egg production and reduction in the size of the layer.

(iv) Tolerance to high temperature.
Question 47
Mention four advantages of fishery.
Solution 47
Advantages of fishery:

(i) Economically important desired fishes are raised in a small area.

(ii) Fishes are made to breed in different seasons.

(iii) There is little mortality in the younger stages of the fishes.

(iv) Through selective hybridization, yield and quality of fishes are improved.
Question 48
Write a short note on 'Prevention of poultry diseases'?
Solution 48
Poultry diseases can be prevented by giving good management practices. The growers require enough space as overcrowding tends to suppress their growth. Adequate lighting should be there. They should be provided with proper feed. Clean and hygienic conditions are must to keep them in good health and prevent them from diseases.
Question 49
Write advantages of bee keeping.
Solution 49

Bee keeping is the rearing of honey bees which provide us with useful products such as honey, wax, propolis, royal jelly and bee venom.

Question 50
What are the advantages of composite fish culture?
Solution 50
Composite fish culture is advantageous and economical. It yields about 8-9 times more production than monoculture. All the species of fish live in distinct zone inside the pond and have distinct feeding habits.

Chapter 1 - Improvements In Food Resources Exercise 65

Question LAQ - 11

What is artificial insemination? Describe this technique.

Solution LAQ - 11

Artificial insemination is the process of injecting the semen obtained from a desired male bull of high milk yielding breed into the genital or reproductive tract of female animal during heat period.

Steps involved in artificial insemination are:

(i) The semen of healthy and tough animal of high milk yielding breed is collected.

(ii) It is preserved by freezing or chemical methods.

(iii) The preserved semen is then injected into the genital tract of the female animal.

(iv) The preserved semen is injected during fertility period.

Question LAQ - 12

Write a short note on prevention of animal diseases.

Solution LAQ - 12

Prevention of animal diseases:

(i) The shelters should have roofed sheds which protects them from rain, heat, direct sunlight and cold.

(ii) The shelters should be provided with cross ventilation.

(iii) The floor of the cattle shed is made brick lined for facilitating cleaning and dry floor.

(iv) Animals must be protected from diseases caused by virus, bacteria and fungi by giving them proper treatment and vaccinating them on time.

(v) Proper nutritional requirements should be given to them so that they do not suffer from nutritional deficiency diseases.

Question LAQ - 13
How bee colony works? What values can be seen in the organisation of bee colony?
Solution LAQ - 13

Honey bee lives in a colony and different tasks are done by different groups of bees in the same colony. According to their roles, there are three types of castes in the colony of bee:

(i) Queen - The body size of queen is much larger than other castes of bees of the colony. Queen is responsible for laying eggs and lays upto 200 eggs everyday of each season.

(ii) Drone - It is haploid, fertile male. These are larger in size than workers. They are stingless and their main role is to mate with queen and remain in colony to sleep and eat honey.

(iii) Worker - Worker is diploid, sterile female. Its size is smallest among the caste of bees. They are the active members of the colony. For various outdoor and indoor chores, the workers are provided with a variety of organs such as hypopharyngeal glands (for secretion of bee milk), wax glands (for building cells of comb), pollen baskets on their hind legs (for collection of pollen), sucking type mouth parts (for collecting the nectar), high level secretion of invertase enzyme (in the honey sac for honey formation), a sting at the tip of the abdomen (for defence of the colony.

Honey bees provide a good example of team work and division of labour.

Question LAQ - 14

Write down the desirable characters bee variety suitable for bee keeping.

Solution LAQ - 14

Italian bee is commonly domesticated in India to increase the yield of honey. It is preferred because:

(i) It is gentle in nature.

(ii) It has good honey collection capacity.

(iii) It has the ability to protect itself from enemies.

(iv) It has prolific queen with less swarming.

Question LAQ - 15

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

Solution LAQ - 15

The pasturage means the flowers available to the bees for nectar and pollen collection. In addition to adequate quantity of pasturage, the kinds of flowers available will determine the taste of the honey.

Pasturage of honey bee includes a variety of flowering plants such as Mango, Cotton, Litchi, Shishame, Apple, Cashew, Coffee, Rubber plant, Sunflower, Neem, etc.

Question LAQ - 16

For increasing production, What is common in poultry, fisheries and bee-keeping?

Solution LAQ - 16

For increasing production, the common feature in poultry, fisheries and bee keeping are:

(i) Quality and quantity of x.

(ii) Low maintenance requirement.

(iii) Tolerance to high temperature.

(iv) Care to prevent mortality.

(v) To increase their productivity, cross breading should be done.

Question LAQ - 17
how do you differentiae between capture fisheries, inland fisheries and aquaculture?
Solution LAQ - 17

Capture Fishery

Culture Fishery

Inland Fishery

(i) It is method of obtaining fish from natural resources.

(ii) There is no seeding and raising of fish.

(iii) It is undertaken in both inland and marine waters.

(i) It is a method of obtaining fish from fish farming.

(ii) The fish is seeded and reared.

(iii) It is undertaken mostly inland and near sea shore.

(i)It is a method of obtaining fish from fresh water resources such as canals, rivers, etc and brackish water resources where sea water and fresh water mix together.

(ii) The fish is seeded and reared.

(iii) Most fish production is through aquaculture.

 

Question LAQ - 18

Explain the role of workers in a bee colony.

Solution LAQ - 18

Worker - Worker is diploid, sterile female. Its size is smallest among the caste of bees. They are the active members of the colony. For various outdoor and indoor chores, the workers are provided with a variety of organs such as hypo pharyngeal glands (for secretion of bee milk), wax glands (for building cells of comb), pollen baskets on their hind legs (for collection of pollen), sucking type mouth parts (for collecting the nectar), high level secretion of invertase enzyme (in the honey sac for honey formation), a sting at the tip of the abdomen (for defence of the colony.

The worker bees of a hive fall under 3 groups. These are:

(i) Scavenger Bees - For the first three days each worker bees act as a scavenger.

(ii) Nurse Bees - From the fourth day onwards each worker bee feeds the entire brood, like a foster mother, with a mixture of honey and pollen. By seventh day, its starts producing royal jelly, which is fed to the queen and future queen bees. They also perform guard duties.

(iii) Foraging or Field bees - They explore new sources of nectar. They collect nectar, pollen and propolis. Nectar is changed into honey in the crops.