Class 9 Science Chapter 12 Important Extra Questions

Increases food grain production.

Increased production and more efficient management of milk.

Availability of food and access to it.

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

Pulses like gram, peas, lentils, etc.

Berseem and Sudan grass.

Duration of sunlight.

From the month of June to October.

From the month of November to April.

Paddy and maize.

Wheat and mustard

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

Genetically modified crop.

Ans. Higher yield and improved quality.

Sixteen.

Farm yard manure.

Neem

The scarcity or irregular distribution of rainfall causes droughts.

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

Maize, potato, sugarcane, peas

Egg (12 per cent)

Milk and meat.

Milk producing females of dairy animals are called milch animals.

Jersey and Brown Swiss.

Red Sindhi and Sahiwal.

A healthy animal feeds regularly and has a normal posture.

Stomach and intestine- Worms; Liver – Flukes

Murrah and Mehsana

Brown Swiss.

Iron

Sunflower.

For increases in fish production.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

(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.

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.

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

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.