Class 9 Science Chapter 15 Important Questions

Class 9 Science Chapter 15 Important Questions of Improvement of Forest Resources. 9th Science Extra Question answers are helpful during the revision of chapter for class assessments.

All the questions are taken from NCERT Textbook for class standard 9 Science only. Answers and explanation also confined to CBSE NCERT course only.

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Class 9 Science Chapter 15 Important Questions for 2020-2021

Class 9 Science Chapter 15 Important Extra Questions Set – 1

What has green revolution led to?

Increases food grain production.

What has white revolution led to?

Increased production and more efficient management of milk.

Name the two factors on which food security depends.

Availability of food and access to it.

What should we do for a sustained livelihood?

We should adopt practices like mixed farming, intercropping and integrated farming practices.

Which food items primarily supply proteins?

Pulses like gram, peas, lentils, etc.

Name any two fodder crops.

Berseem and Sudan grass.

Why are improved poultry breeds developed? Describe the desirable traits for which new varieties are developed

Poultry farming is undertaken to raise domestic fowl for egg production and chicken meat. For this, improved poultry breeds are developed and farmed to produce layers for eggs and broilers for meat.
The cross-breeding programmes between Indian (indigenous like Aseel) and foreign (exotic like Leghorn) breeds for variety improvement are focused on developing new varieties for the following desirable traits:

    1. The number and quality of chicks.
    2. Dwarf broiler parent for commercial chick production.
    3. Tolerance to high temperature.
    4. Low maintenance requirements.
    5. Reduction in the size of the egg-laying bird possessing the ability to utilise more fibrous and economical diet that are formulated using agriculture by-products.




Class 9 Science Chapter 15 Important Extra Questions Set – 2

What are photoperiods related to?

Duration of sunlight.

What is the duration of kharif seasons?

From the month of June to October.

What is the duration of Rabi seasons?

From the month of November to April.

Name two kharif crops.

Paddy and maize.

Name two rabi crops.

Wheat and mustard

Name the three stages in which farming practices are divided.

(1) Choice of seeds (2) Nurturing of crop plants and (3) Protection of the growing and harvest crops.

Humane Farming

It means providing proper and clean shelter facilities to cattle for their health as well as for the production of clean milk. The animals are brushed to remove dirt and loose hair, They should be sheltered in well ventilated sheds with roofs so that they are protected from rain, heat and cold. Also the floor of the cattle shed needs to be sloping so that water logging does not happen and it remains dry.

Class 9 Science Chapter 15 Important Extra Questions Set – 3

What is the name given to crops obtained by introducing a gene that provides the desired characteristic?

Genetically modified crop.

Name any two factors for which crop variety improvement is done.

Ans. Higher yield and improved quality.

How many nutrient are essential for plants?

Sixteen.

What is FYM?

Farm yard manure.

Name a biopesticide.

Neem

What do droughts occur?

The scarcity or irregular distribution of rainfall causes droughts.

What is green manure?

Some plants like sun hemp or guar are grown in the field prior to the sowing of the crop seeds. These are then mulched by ploughing them into the soil. These green plants gradually decompose and turn into green manure which helps in enriching the soil in nitrogen and phosphorous.




Class 9 Science Chapter 15 Important Extra Questions Set – 4

What is the main benefit of mixed cropping?

It reduces production risk and gives insurance against failure of all the crops.

Give an example of crops grow in two year rotation.

Maize, potato, sugarcane, peas

Which one has more fat content egg or meat?

Egg (12 per cent)

Name any two source of vitamin B2 and B12.

Milk and meat.

What are milch animals?

Milk producing females of dairy animals are called milch animals.

Name two foreign cattle breeds that are selected for long lactation periods.

Jersey and Brown Swiss.

Useful Traits in Improved Crop

Some useful traits in improved crops are:

    • Higher yield of crop.
    • Improved quality of crop.
    • Biotic and abiotic resistance.
    • Change in maturing duration.
    • Wider adaptability and
    • Desiratable agronomic characteristic.

Class 9 Science Chapter 15 Important Extra Questions Set – 5

Name two cattle breeds which show excellent resistance of diseases.

Red Sindhi and Sahiwal.

Mention two signs of a healthy animal.

A healthy animal feeds regularly and has a normal posture.

Name the internal parasites which affect the stomach, intestine and liver in cattle.

Stomach and intestine- Worms; Liver – Flukes

Name two breeds of buffaloes.

Murrah and Mehsana

Name one exotic breeds of cattle.

Brown Swiss.

Name a nutrient which is not present in fertilizer.

Iron

What do you understand by organic farming?

Organic farming is a farming system in which there is minimal or no use of chemicals such as fertilisers, herbicides, pesticides etc. There is maximum input of organic manure, recycled farm wastes i.e. straw and livestock excreta, use of bio-agents such as culture of blue green algae in preparation of biofertilisers. Also neem leaves or turmeric is used specially in grain storage which act as biopesticides. It employs healthy cropping system (mixed cropping, inter cropping and crop rotation).



Class 9 Science Chapter 15 Important Extra Questions Set – 6

Name one oil yielding plant.

Sunflower.

What was blue revolution meant for?

For increases in fish production.

Why should beekeeping be done in good pasturage?

Beekeeping is done in good pasturage because good pasturage provides more quantity and quality of nectar for honey to the honey bee.

Can increasing grain production alone solve the problem of malnutrition and hunger?

No, increasing grain production only for storage in warehouse cannot solve the problem of malnutrition and hunger. Food security depends both on availability of food and acess to it. As the majority of our population depends on agriculture for their livelihood, increasing the incomes of people of working in agriculture thus becomes necessary to combat the problem of hunger.

In agriculture practices, higher input gives higher yield. Discuss how?

Higher input means good financial conditions of the of the farmers so that they can employ good and improved farming technologies. Thus these would give higher yields.

What happens due to deficiency of nutrients?

Nutrients are required by the plants for maintaining their healthy and every living process occurring in their bodies. Deficiency of nutrients affects the various physiological processes in plants like reproduction, growth, susceptibility to diseases like ponds, canals, reservations and rivers and called composite fish culture.

What is honey?

Honey is a dense sweet liquid that contains 20 – 40 per cent sugar, 60 – 80 per cent moisture, 0.22 – 0.3 per cent minerals and 0.2 – 0.5 per cent vitamins. Apart from that it also contains certain enzymes and pollen. Uses of honey are as follows:

    • Honey has medicinal value specially in disorders that are related to digestion and liver ailments.
    • As it contains iron and calcium, it also helps in the growth of the body.
    • It is used as a source of sugar in various confectionery items.

Class 9 Science Chapter 15 Important Extra Questions Set – 7

How is the use of manure beneficial for our environment?

Manure is beneficial because they help in:
(a) Producing the damage of environment from chemicals such as pesticides and fertilizers.
(b) Recycling the biological waste i.e. animal excreta and plant wastes, thus preventing accumulation of these things.

Name two types of animal feed and write their function?

The two types of animal feed are:
(i) Roughage: These are rich in fibre for example cowpea, berseem, etc.
(ii) Concentrates: These are nutrient-rich and low on fibres example oats, maize etc.

What is GM crop? Name any one such crop which is grown in India.

Crop which has been developed by introducing a new gene from a different source to obtain the desired character is called genetically modified (GM) crop. For example, Bt cotton which is made insect-resistance by introducing a new gene from a bacteria.

Write the modes by which insects affect the crop yield.

Insects have a damaging effect on the crop yield. Some insects cut the plant parts inhibiting their growth while others suck the cell sap so bees cannot help in pollination. Some insects are even seen as the bore which damage the entire crop yield.

Why is excess use of fertilizers detrimental for the environment?

Fertilisers are inorganic chemicals which are not easily degraded. Excess use of fertilisers causes environmental pollution as their residual and unused amounts will become pollutants for air, water and soil.

Differentiate between compost and vermicompost.

Compost: It is prepared by the process in which farm waste materials like livestock excreta, vegetables wastes, animal refuse, domestic waste, straw, eradicated weeds are decomposed and used as manure.
Vermicompost: It is the compost prepared from inorganic matter using earthworms which hasten the process of decomposition.

Why should pesticides be used judiciously?

Pesticides are the chemicals that are used to control weeds, rodents, fungi as well as diseases of plants. Their excessive use causes environmental pollution. They reach the water resources and affect the aquatic flora and fauna. These harmful chemicals reach the bodies of birds, animals and human beings through various food chains and thus, harmful to all depending on their concentration in the body.

Class 9 Science Chapter 15 Important Extra Questions Set – 8

An Italian been variety A. mellifera has been introduced in India for honey production. Write about its merits over other varieties.

Merits of Italian bee variety A. mellifera are:
(a) It stings less.
(b) It has high honey collection capacity.
(c) It stays in the given beehive for longer periods and breeds very well.

What mineral nutrients are supplied to the plants by air, water and soil?

Air supplies two nutrient to plants namely carbon and oxygen. Water supplies hydrogen and soil supplies thirteen nutrient elements to the plants. Among these thirteen nutrients are nitrogen, phosphorous, potassium, calcium, magnesium and sulphur while the micronutrients are iron, manganese, boron, zinc, copper, molybdenum and chlorine.

What are pathogens? Name any two plant diseases caused by pathogens?

The diseases causing microorganism like bacteria, fungi and viruses are called pathogens. They reach the plants through water, air, soil as well as seeds.
Two plant diseases caused by pathogens are rust in wheat and blast in paddy stem rot in pigeon pea.

What are the types of food requirements of diary animals? Why do external and internal parasites live on and in the cattle can be fatal?

They are two types of food requirements of dairy animals:
(i) Maintenance requirement, which is the food required to support the animal to live a healthy life.
(ii) Milk producing requirement which is the food required during the lactation period.
The external parasites live on skin mainly cause skin diseases. The external parasites like worms, affect stomach and intestine while flukes damage liver.

Write the names and the average yield of the three important breeds of buffaloes of our country with high yield of milk.

(a) Murrah: It is the original breed of Haryana and Punjab. The average yield of milk is 1800-2500
litres during lactation period.
(b) Mehsana: This breed belongs to Gujarat, specially Mehsana and Vadodara districts. Average yield is about 1200 – 2500 litres during lactation period.
(c) Surti: These are native of Kaira and Vadodara districts of Gujarat. The milk production during lactation period is about 1600- 1800 litres.

Which factors should be taken into consideration for fish culture?

The three important factors to be considered for fish culture are:
(a) Topography, i.e. location of pound.
(b) Water resources and their quality.
(c) Soil quantity.

Questions for Practice

(a) Give any three preventive measure for pest control.
(b) What preventive and control measures are used before grains are stored for future use?

Answers

(a) The three important preventive measures for pest control are:
(i) Employing crop rotation.
(ii) Use of pest-resistant varieties.
(iii) Employing optimum time of sowing the crops.
(b) Preventive and control measures are used before grains are stored for future use, which include strict cleaning of the produce before storage, proper drying of the produce first in sunlight and then in shade, and then in shade, and fumigations by using chemicals that kill pests.

Class 9 Science Chapter 15 Important Extra Questions Set – 9

Name the indigenous fowls of India. Which among them is the most popular.

Indigenous fowl varieties of India are:
(i) Aseel
(ii) Ghagus
(c) Chittagong
(d) Busra
Of these, aseel is the most popular which provides high yield of meat but is a poor egg layer

What are the important precautions that should be taken in poultry farming?

In poultry farming the following precautions should be taken:
(i) Proper poultry feed.
(b) Proper vaccination of birds.
(c) Preventions and control of diseases and pests.
(d) Isolation of diseased birds.
(e) Maintenance of optimum temperature and hygienic conditions in housing.

What are poultry diseases and how can they be prevented?

Poultry fowl suffers from a variety of diseases caused by virus (Dermitis), bacteria (Tuberculosis) fungi (Aspergillosis), parasites like worms mites as well as from nutritional deficiencies. These necessities proper cleaning, sanitation and spraying of disinfectants at regular intervals. Appropriate vaccination can also prevent the occurrence of infectious diseases and reduce the loss of poultry during an outbreak of a disease.

Why is animal husbandry essential?

Animal husbandry is essential because of the following reasons:
(a) To increase milk production. It also increases the production of various milk products like butter and cheese.
(b) To increase egg and meat production which are highly nutritious.
(c) To increase fish production.
(d) For the proper utilisation of animal wastes.

What are the advantages of beekeeping?

Following are the main advantages of beekeeping:
(a) Along with getting honey on a commercial scale, other products like wax, royal jelly and bee venom are also obtained from beekeeping.
(b) Beekeeping requires low investments due to which farmers, along with agriculture also do beekeeping to generate additional income.
(c) It also helps in cross-pollination as pollen are transferred from one flower to another by the bees while collecting nectar.

Name two infectious diseases each of cows, poultry and fishes.

(a) Cows – Anthrax and Foot and mouth disease
(b) Poultry- Ranikhet and Salmonellosis.
(c) Fishes – Viral Hemorrhagic Specticemia (VHS) and Infectious Pancreatic Neccrosis (IPN)

Name the two types of fish that come under fish production

The two type of fish are:

    1. True fin fishes, i.e. fishes that have fins like carps, catla, mrigal etc.
    2. Shellfish like prawns, molluscs, echinoderms, etc.



Class 9 Science Chapter 15 Important Extra Questions Set – 10

How is fish meant advantageous than meat of other animals?

Fish meat is considered advantageous than the meat of other animals because:
(a) It is rich in proteins (13 – 20 per cent) and has less fats.
(b) It is a rich source of Vitamin A and D.
(c) It is rich in iodine that is essential for thyroxine formation.
(d) It is more easily digestible than the meat of other animals.

What are the main elements of animal husbandry?

The main elements of animal husbandry are:
(a) Proper feeding of animals.
(b) Providing freshwater to animals.
(c) Providing safe and hygienic shelter to animals.
(d) Ensuring proper health of animals and protection against diseases.
(e) Proper breeding of animals.

Enumerate the advantages of mixed farming.

Following are the main advantages of mixed farming:
(a) Farmyard manure is made available from livestock which is used again in agricultural farms.
(b) Organic wastes materials like straw, husks and chaffos of grains, household kitchen waste etc., are convert into human food through the agency of cattle, sheep, poultry, pigs, etc., as per the choice of farmer.
(c) It provides work to all the memberd of a family throughout the year, thus providing substdiary occupation without the need of employing special labour.
(d) Adopting exact combination in mixed farming, income can be increased for example the number of animals can be increased (as per the food/crop available) to enhance milk production.

Give the merits and demerits of fish culture.

Demerits: (i) Threat to biodiversity,
(ii) only economically important valued fishes will be cultured.
Merits: (i) Large amount of desired fishes can be obtained in small area,
(ii) Increased quality of food as fishes are cheaper source of protein.

Discuss why pesticides are used in very accurate concentration and in very appropriate manner.

Pesticides are used in very accurate concentration and in a very appropriate manner because if used in excess it
(a) harms the soil and causes loss of fertility.
(b) checks the replenishment of organic matter.
(c) kills the microorganism of soil,
(d) cause air water and soil pollution.

Why is organic matter important for crop production?

Organic matter is important for crop production because:

    • It helps in improving soil structure.
    • It helps in increasing water holding capacity of sandy soil.
    • In clayey soil, large quantities of organic matter helps in drainage and in avoiding waterlogging.

Class 9 Science Chapter 15 Important Extra Questions Set – 11

Why is crop variety important in cultivation? Describe the important factors for which variety improvement is done.

As we know, whether conditions, soil quality and availability of water are the main factors on which crop yield depeds. As weather coditions like droughts and flood situation are unpredictable, it is important to have varities that can grow in adverse climatic conditions. In the same way, varities that are tolerant to high soil salinity have also been developed. Some of the factors for which crop variety that are tolerant to high soil salinity have also been developed. Some of the factors for which crop variety improvement is done are as follows:
(a) High Yield: To increase the productivity of the crop per acre.
(b) Improve Quality: Quality considerations of crop products vary from crop tp crop. For instance, baking quality is important in wheat, protein quality in pulses; oil quality in oilseeds and preserving quality in fruits and vegetables.
(c) Biotic and Abiotic Resistance: Crop production can fall due to biotic and abiotic stresses under different situations. Thus, varieties resistance to these stresses can improve crop production.
(d) Change in Maturtity Duration: The shorter the duration of the crop from sowing to harvesting more economical is the variety. It reduces the cost of crop production and allows the farmers to grow multiple crops in a year.
(e) Wider Adapatbility: Developing varieties for wider adaptability helps in stabilishing the crop production under different environmental conditions. Also, one variety can then be grown under different climatic conditions in different areas.
(f) Desirable Agronomic Characteristics: Height and profuse branching are desirable characteristics for fodder crops. Dwarfness is desired in cereals such that fewer nutrients are consumed by these crops. Thus, feveloping varieties of desired agronomic characters also help in higher yield.

Describe the main irrigation systems that are adoped in India.

Different kinds of irrigation systems are adopted to supply water to agricultural lands depending on the kinds of water resources available. These include wells, canals, rivers and tanks.
(a) Wells:They are of two types- dug wells and tube wells. In dug wells, water is collected from water bearing strata while in tube wells water is tapped from the deeper strata. From these wells, water is lifted by pumps for irrigation.
(b) Canals: Canal system is ususlly an elaborate and extensive irrigation system. Canals receive water from one or more reservations or from rivers. The main canal is divided into branch canals having further distributaries to irrigate fields.
(c) River lift systems: In this system, water is directly drawn from the rivers for supplementing irrigations in areas lying close to rivers. This systems is used in areas where canal flw is insufficient or irregular due to inadequate reservoirs release.
(d) Tanks: Tanks are small storage reservoirs, which intercept and store the run-off of smaller catchment areas.
Apart from the above systems, some new initiatives have been undertaken for increasing the water available for agriculture. These include rainwater harvesting system and watershed management system. This involves building small check dams which lead to an increase in groundwater levels. These check dams stop the rainwater from flowing away and also reduce soil erosion.

Enlist the criteria for the selection of crops for mixed cropping.

Mixed cropping is employed to minimise risk and as an insurance against crop failure due to abnormal weather conditions. The main criteria’s for selection of the crops for mixed cropping are as follows:
(a) Duration of crops: One of the crops should be a long duration and other should be a short duration crop.
(b) Growth Habit: One of the crops should be growing tall and the other should be growing short. The component crops should have different canopy (i.e. the structure of leaves, stem and flowers found above the ground).
(c) Nutrient Demand: One of the component crops should require lesser nutrients than the other crop.
(d) Root Pattern: One of the crop should be deep-rooted while the other should be shallow rooted.
(e) Water Requirement: One of the component crops should require lesser water than the other.

What are weeds? Enlist the methods employed to control weeds.

The unwanted plants in a cultivated field are called weeds. They compete for food, space and light with the main crop plants. They germinate and grow faster, and thus effect the quality and yield of the crop. For these reasons weed plants are removed from the cultivated field in early stage of crop. The methods employed for weed control are as follows:
(a) Mechanical Method: The weed plants are removed from the field either manually or with the help of agricultural implements like uprooting or hand hoeing or weeding with khurpi, ploughing etc.
(b) Cultural Methods: This method includes:
(i) Proper seed bed preparation
(ii) Timely sowing of crops
(iii) Intercropping
(iv) Crop rotation
(c) Chemical Methods: By spraying chemicals that do not harm crop plants but destroy only the weed plants, the latter can be controlled. These chmicals are called weedicides e.g., 2, 4-D and atrazine.
(d) Biological Method: As we know, some insects feed an particular weeds. Thus, we use these insects as biological weed-controlling agents like the use of cochineal insect to control Opuntia weed and the use of the grass carp fish to control aquatic weeds.

Describe composite fish culture system. What is the major problem in fish farming? How is it overcome?

By adopting composite fish culture systems, intensive fish farming can be done. Both local and imported fish species are used in such systems. In such a system, a combination of five or six fish species is used in a single fish pond. These species are selected in such a way that they have different types of food habits and don’t compete for food among themselves. As a result, the food available in all the parts of the pond of the pond is used.
For example: Catals are surface feeders, Rohus feed in the middle-zone of the pond, Mrigals and Common Carps are bottom feeders, and Grass Craps on the weeds. Together these species can use all the food in the pond without competing with each other. This naturally increases the fish yield from the pond.
One problem with such a composite fish culture is that many of these fishes breed only during monsoon. Even if fish seed is collected from the wild, it can mixed with that of other species as well. So a major problem in fish farming is the lack of availability of good quality seed. To overcome this problem now some way have been worked out to breed these fish in ponds using hormonal stimulation. This has ensured the supply of pure fish seed in desired quantities.

Difference between Mixed Cropping and Intercropping Cropping

Mixed CroppingIntercropping Cropping
1. There is no definite patterns of rows.1. Crops are grown in definite pattern of rows like 1:1, 1:2 or 1:3.
2. It is undertaken to reduce the chances of crop failure.2. It is undertaken to enhance the production of crops per unit area.
3. Mixed cropping cannot be done separately for crops.3. In intercropping crops can be harvest as well as threshed separately.
4. Seeds are mixed up before sowing.4 Seeds are not mixed before sowing.
5. Applications of fertilizers and spraying of pesticides for separate crops is not possible.5. As per the need of the individual crop, fertilisers as well as pesticides can be applied easily.



Difference between Fertilizers and Manures

FertilizersManures
1. They are inorganic substances which are manufactured in factories.1. Manure is an organic substance that is obtained from decomposition of vegetable and animal waste.
2. Microbs are not needed for their formation.2. Microbes degrade the organic substances to form manure.
3. Easy to transport, store and apply to crops.3. It is difficult to transport, store and apply manure to crops.
4. They do not restore soil texture.4. They restore soil texture.
5. They do not help in retention of water.5. They help in the retention of water.