RBSE Solutions Class 9 Science Chapter 15 Natural Resources and Agriculture

Natural Resources and Agriculture Textbook Questions Solved

Objective Type Questions

Question 1. Growing of different crops in pre-planned succession is called as-
(a) Mixed Cropping
(b) Mixed Farming
(c) Crop rotation
(d) Intercropping
Answer: (c) Crop rotation
In simple words: When farmers plant different kinds of crops one after another in the same field in a planned way, it is called crop rotation. This helps to keep the soil healthy.

🎯 Exam Tip: Understanding different farming techniques is key; ensure you know the specific definitions for mixed cropping, crop rotation, and intercropping.

Question 2. The average amount of \( \text{CO}_2 \) in the atmosphere is:
(a) 0.03%
(b) 0.003%
(c) 0.0003%
(d) 0.3%
Answer: (a) 0.03%
In simple words: Carbon dioxide makes up a very small part of the air we breathe, usually around 0.03 percent. Even a small change in this amount can affect the Earth's climate.

🎯 Exam Tip: Remember this percentage, as it is a fundamental fact about atmospheric composition and climate science.

Question 3. Which of the following causes acid rain?
(a) Air pollution
(b) Water pollution
(c) Soil pollution
(d) Sound pollution
Answer: (a) Air pollution
In simple words: Acid rain happens because of harmful gases released into the air from factories and cars. These gases mix with water in the clouds and fall as acidic rain.

🎯 Exam Tip: Focus on the main pollutants like sulfur dioxide and nitrogen oxides that lead to acid rain.

Question 4. Which one of the following nutrient is found in plants, by soil?
(a) Carbon
(b) Hydrogen
(c) Oxygen
Answer: (a) Carbon
In simple words: While plants contain a lot of carbon, they mainly get it from the carbon dioxide in the air, not directly as a nutrient from the soil. The soil primarily provides water and other mineral nutrients.

🎯 Exam Tip: Distinguish between elements that make up plant biomass (like carbon, hydrogen, oxygen) and mineral nutrients absorbed from the soil (like nitrogen, phosphorus, potassium).

Natural Resources and Agriculture Very Short Answer Type Questions

Question 6. Name the instrument which is used to measure the movement of air?
Answer: An anemometer is used to measure the movement of air. This tool helps us understand wind speed and patterns.
In simple words: An anemometer is a tool that measures how fast the wind is blowing.

🎯 Exam Tip: Remember specific instruments used for environmental measurements, as they are common knowledge questions.

Question 7. Define pollution?
Answer: Pollution is when human actions release harmful substances into the earth, water, or air. These substances change the natural makeup of the environment, causing harm. For example, smoke from cars causes air pollution.
In simple words: Pollution is when harmful things from human activities spoil our environment, like air, water, or soil.

🎯 Exam Tip: A good definition includes the cause (human activities), the nature of the change (harmful substances), and the affected areas (earth, water, air).

Question 8. What are natural resources?
Answer: Natural resources are things found in nature, like air, water, soil, coal, minerals, animals, and plants. These resources are valuable to people in many ways. Sunlight is also a natural resource that provides energy.
In simple words: Natural resources are useful things we get from nature, like water, air, and plants.

🎯 Exam Tip: Provide a few examples of natural resources to fully explain your answer.

Question 9. What is Algal bloom?
Answer: Algal bloom happens when there is too much sewage and fertilizers in polluted water. These provide many nutrients, causing algae to grow very fast in the water body. This rapid and excessive growth of algae is known as an algal bloom, which can harm aquatic life.
In simple words: Algal bloom is when too much algae grows in water because of pollution, often from sewage or fertilizers.

🎯 Exam Tip: Link algal blooms directly to excess nutrient availability in water due to pollution.

Question 10. What is sonic boom?
Answer: A sonic boom is a loud, explosive noise caused by the shock waves created when an object, like an aircraft, moves faster than the speed of sound. This creates a sudden change in air pressure.
In simple words: A sonic boom is a loud sound made when something, like a jet, flies faster than sound itself.

🎯 Exam Tip: Remember that sonic booms are caused by objects breaking the sound barrier, generating shock waves.

Question 11. What is mixed farming?
Answer: Mixed farming is a type of farming where both crops are grown and livestock are raised on the same farm. This helps farmers to use their resources efficiently.
In simple words: Mixed farming is when a farm grows crops and also keeps animals at the same time.

🎯 Exam Tip: Highlight the dual nature of mixed farming (crops + livestock) as its distinguishing characteristic.

Question 12. Name the gas found in maximum percentage in the atmosphere? '
Answer: Nitrogen gas (78.09%) is found in the highest percentage in the atmosphere. It is an essential component for life, especially for plant growth.
In simple words: Nitrogen gas makes up most of the air, about 78%.

🎯 Exam Tip: Recall the main gases in the atmosphere and their approximate percentages.

Question 13. Which gas is used by plants in the respiration?
Answer: Oxygen. Just like animals, plants also breathe in oxygen for respiration, especially at night.
In simple words: Plants use oxygen when they breathe.

🎯 Exam Tip: Remember that while plants produce oxygen during photosynthesis, they consume it during respiration.

Question 14. What is the reason for the movement of air?
Answer: Air moves because of temperature differences in our atmosphere. When air gets heated, it rises, and cooler air moves in to take its place, creating wind and air currents. This movement also helps in the formation of water vapor, which is part of the water cycle.
In simple words: Air moves because some parts of the air get warm and rise, and cooler air rushes in to fill that space.

🎯 Exam Tip: Connect air movement directly to the uneven heating of the Earth's surface and the resulting pressure differences.

Question 15. Write the name of an exotic breed of poultry bird having high egg laying capacity?
Answer: White Leghorn. This breed is well-known globally for its excellent egg production.
In simple words: The White Leghorn is a type of chicken from another country that lays many eggs.

🎯 Exam Tip: Be able to name common high-yielding breeds of livestock and poultry.

Natural Resources and Agriculture Short Answer Type Questions

Question 16. What is Humus? What are the advantages of Humus?
Answer: Humus is a dark, organic material made from plants and animals that have partially or fully decayed. It is very good for soil health.
Humus has several advantages:
1. It gives important nutrients to plants.
2. It helps the soil hold more water, which is important for plant growth.
3. Humus plays a big part in making the soil structure better, making it porous. This allows water and air to get deep into the soil.
4. Humus acts as a food source for beneficial soil microorganisms.
In simple words: Humus is dark, decayed stuff in soil from old plants and animals. It helps plants get food and makes the soil hold water and air better.

🎯 Exam Tip: When explaining humus, always mention its organic nature, dark color, and its dual role in nutrient supply and improving soil structure/water retention.

Question 17. What is acid rain? Explain its formation with equations and its harmful effects.
Answer: Acid rain is precipitation that contains harmful dissolved gases, primarily nitrogen pentaoxide, sulfur dioxide, and sulfur tri-oxide, which form nitric acid and sulfuric acid in the atmosphere.
Its formation involves these chemical reactions:
\( \text{NO} + \text{O}_3 \rightarrow \text{NO}_2 + \text{O}_2 \)
\( \text{NO}_2 + \text{O}_2 \rightarrow \text{NO} + \text{O}_2 \)
\( \text{NO}_2 + \text{NO}_3 \rightarrow \text{N}_2\text{O}_5 \)
\( \text{N}_2\text{O}_5 + \text{H}_2\text{O} \rightarrow 2\text{HNO}_3 \) (Nitric acid)
\( \text{SO}_2 + \text{O}_2 + 1/2\text{H}_2\text{O} \rightarrow \text{H}_2\text{SO}_4 \) (Sulphuric acid)
These acids fall back to Earth with raindrops, causing acid rain.
Harmful effects of Acid Rain:
1. Acid rain kills fish and other aquatic animals and plants.
2. It causes irritation in the eyes and skin of humans.
3. It removes important nutrients from plant leaves.
4. It makes the soil more acidic, which negatively affects crop growth.
5. It reacts with building materials like marble and limestone, weakening them through corrosion.
6. Acid rain weakens bridges and other structures, posing a risk of collapse.
7. Heavy metals such as cadmium, zinc, copper, and nickel separate from mineral ores due to acid rain. These metals then flow into lakes and rivers with rainwater, causing water pollution.
In simple words: Acid rain happens when pollution from gases like sulfur and nitrogen mixes with water in the air, creating strong acids that fall as rain. This rain harms plants, animals, buildings, and water bodies.

🎯 Exam Tip: When describing acid rain, always include the key pollutants, the types of acids formed, and at least three distinct negative impacts on the environment or human infrastructure.

Question 18. What is BOD?
Answer: BOD stands for Biological Oxygen Demand. It shows how good or bad wastewater quality is. BOD measures how much dissolved oxygen bacteria need to break down the organic waste in water. It is measured in milligrams of oxygen per liter of water. A high BOD means there is a lot of pollution.
In simple words: BOD tells us how dirty water is by measuring how much oxygen tiny living things need to clean up the waste in it.

🎯 Exam Tip: Define BOD clearly and explain what a high or low BOD value indicates about water quality.

Question 19. Describe the harmful effects of air pollution?
Answer: Air pollution has several harmful effects on human health:
4. Smoke and dust particles in the air can cause coughing, asthma, and tuberculosis.
5. Gases from petrol and diesel vehicles, such as carbon monoxide and tetramethyl lead, can cause cancer and tuberculosis if breathed in for a long time.
In simple words: Air pollution makes us sick, causing problems like coughs, asthma, and even serious diseases like cancer, especially from vehicle fumes and dust.

🎯 Exam Tip: Focus on linking specific air pollutants to common health issues, such as respiratory problems and chronic diseases.

Question 20. What is biological magnification? Explain.
Answer: Biological magnification happens when pesticides and other chemicals from farms, like DDT, enter water sources due to rain. These chemicals then get into the food chain. Because these chemicals cannot be broken down by living organisms, their concentration increases at each step up the food chain. This increase in harmful substance concentration as it moves through trophic levels is called biological magnification, and it can harm animals at the top of the food chain the most.
In simple words: Biological magnification is when harmful chemicals, like pesticides, build up more and more in animals as they eat other animals higher up the food chain.

🎯 Exam Tip: Clearly explain how non-degradable chemicals accumulate and increase in concentration at higher trophic levels in a food chain.

Question 21. What is noise pollution? Explain the harmful effects of noise pollution?
Answer: Noise pollution is any unwanted loud and harsh sound that occurs at the wrong place and time. For example, loud sounds from big machines, factories, cars, and airplanes are considered unwanted. Using loudspeakers at public events or having high-volume radio and TV also adds to noise pollution. The intensity of sound is measured in decibels (dB), with normal conversation usually between 30-50 dB.
Effects of sound pollution on human beings:
1. Audiological effects: Sounds louder than 90 dB can make ears tired and cause a ringing sound. People often exposed to 100 dB noise can become hard of hearing or deaf. Very loud sounds near the ears can even puncture the eardrum, causing deafness.
2. Physiological effects: Loud and unwanted sounds harm how the human body works. Noise pollution can affect eyesight, and it can also harm the heart, liver, breathing system, and brain. It can cause headaches, nausea, skin irritation, high blood pressure, dizziness, and memory loss.
3. Psychological effects: Harsh sounds can lead to anger, irritability, and stress. This can cause disagreements and conflicts among people.
In simple words: Noise pollution is loud, unwanted sound that harms us. It can make us deaf, cause body problems like high blood pressure, and make us feel angry or stressed.

🎯 Exam Tip: Define noise pollution and then categorize its harmful effects into audiological, physiological, and psychological impacts, providing examples for each.

Question 22. What are the causes of soil pollution?
Answer: Causes of Soil pollution are:
1. When debris and waste products mix with the soil, it causes soil pollution.
2. Too much use of pesticides and fertilizers pollutes the soil.
3. Industrial waste discharged into the soil also causes pollution.
4. Dangerous insecticides like DDT are harmful. When these enter the bodies of consumers from producers, their concentration increases because they cannot be broken down. These can stay in the environment for up to 15 years, also causing soil pollution.
In simple words: Soil pollution happens when trash, too many chemicals (like pesticides and fertilizers), or factory waste gets mixed into the soil, making it unhealthy.

🎯 Exam Tip: When listing causes of soil pollution, ensure to include both solid waste and chemical contamination, and briefly explain how they lead to harm.

Question 23. Write any four measures to control air pollution?
Answer: The following devices and measures should be adopted to control air pollution:
1. Factories should use gas-absorbing devices over chimneys to capture harmful gases.
2. Filters should be used to catch large particles of waste material so they do not mix into the air.
3. Vehicles should use suitable and cleaner fuels.
4. The fuel used should produce minimal smoke and fewer harmful gases when burned. For example, using lead-free petrol reduces lead emissions.
In simple words: To control air pollution, factories should use gas filters, and vehicles should use cleaner fuels and be checked regularly to reduce harmful smoke.

🎯 Exam Tip: For control measures, focus on practical actions related to industrial emissions, vehicular pollution, and fuel quality.

Question 24. Write the differences between Manures and Fertilisers.
Answer:

🎯 Exam Tip: Focus on the key differences: origin (organic vs. chemical), nutrient concentration, impact on soil structure, and quantity required.

Question 25. What is vermicomposting? Explain.
Answer: Vermicomposting is a process where earthworms break down organic waste, turning it into valuable compost. Earthworms make the soil more fertile in several ways. Physically, they act as reactors, crushers, and mixers, creating better soil structure. Chemically, they break down organic matter into simpler forms. Biologically, they stimulate decomposition, speeding up the process. In India, many kinds of earthworms are used for vermicomposting, such as Dichogaster bolani and Drawida willsi.
In simple words: Vermicomposting is a way to turn organic waste into good soil by using earthworms, which makes the soil healthy and fertile.

🎯 Exam Tip: Emphasize the role of earthworms in breaking down organic waste and improving soil fertility in multiple ways (physical, chemical, biological).

Question 26. Explain. Organic farming?
Answer: Organic farming is a method of crop and livestock production that involves much more than choosing not to use pesticides, fertilizers, genetically modified organisms, antibiotics, and growth hormones. Instead, organic farming focuses on practices that promote ecological balance and biodiversity. It uses natural methods like crop rotation, green manure, compost, and biological pest control to maintain soil fertility and control pests. This approach aims to create a sustainable agricultural system that is environmentally friendly.
In simple words: Organic farming is a way of growing food and raising animals without using man-made pesticides, fertilizers, or other artificial chemicals, focusing instead on natural methods.

🎯 Exam Tip: When defining organic farming, highlight its core principles: avoiding synthetic inputs and promoting ecological processes.

Question 27. How does artificial rearing done?
Answer: Artificial rearing, particularly for honey production (apiculture), involves raising Italian honey bees (Apis mellifera) on a commercial scale. This breed is preferred in India for its gentle nature, good honey collecting ability, and prolific queen production, along with less swarming and good defense against enemies. Apiaries are set up for commercial honey production.
For artificial bee rearing, an artificial hive is necessary. This hive consists of a large brood chamber, along with wax-coated metal and plastic plates that form the base of the artificial hive. These hives are placed in a garden to attract bees. The blooming period of flowers is the most suitable time for artificial rearing.
Drone bees, which secrete wax from glands in their abdomen, are introduced to prepare wax chambers on these wax-coated plates. Once the honey chambers are completely filled, the plates are removed, and honey is collected. The wax deposited is also separated and used to make bee wax for polishes, creams, and shoe polish. Honey is very good for health and is used in traditional medicines. Apiculture is now practiced professionally, with organizations like Khadi Gram Udhyog encouraging its adoption.
In simple words: Artificial bee rearing means setting up special hives for bees like the Italian honey bee, usually in gardens during flowering times. Bees make honey and wax in these hives, which are then collected.

🎯 Exam Tip: Explain the process of apiculture, mentioning the type of bee, the structure of the artificial hive, and the products obtained.

Question 28. Write the names of high milk yielding breeds of cows and buffaloes?
Answer:
Breed of Cows:
Indigenous (Desi) high milk yielding breeds are:
(a) Gir
(b) Sahiwal
(c) Red Sindhi
(d) Devli
Exotic (foreign) varieties are:
(a) Jersey
(b) Reddane
(c) Holstein
High milk yielding breeds of buffaloes are:
(a) Murrah
(b) Surati
(c) Nagauri
(d) Jaffarbadi
(e) Mehsana
In simple words: Some cows that give a lot of milk are Gir, Sahiwal, Jersey, and Holstein. For buffaloes, Murrah and Surati are good milk-giving breeds.

🎯 Exam Tip: Be sure to differentiate between indigenous and exotic breeds for cows, and include a few key buffalo breeds known for high milk yield.

Question 29. Name the various disease in dairy animals?
Answer: Diseases in dairy animals can be divided into two main categories:
1. Parasitic Diseases: These are caused by parasites that can live both inside and outside the animal's body. External parasites include fleas, lice, ticks, and mites. Internal parasites include different types of worms and flukes.
2. Infectious Diseases: These are mainly caused by viruses and bacteria. They are often contagious and can spread easily among animals.
For Example:
Viral diseases: Foot and mouth disease, Cowpox, and Rinderpest.
Bacterial diseases: Anthrax and Haemorrhagic septicemia.
Caring for animal health is crucial to prevent these diseases from spreading and affecting milk production.
In simple words: Dairy animals can get sick from parasites, like worms or ticks, or from infections caused by viruses (like foot and mouth disease) and bacteria (like anthrax).

🎯 Exam Tip: Classify diseases into parasitic and infectious types, and provide a few examples for each category.

Question 30. What is Mixed Cropping? Write its advantages.
Answer: Mixed cropping is an agricultural practice where two or more crops are grown at the same time on the same piece of land. This method helps farmers use their land efficiently.
Some mixed cropping practices include:
(a) Soybean + Pigeon pea
(b) Wheat + Mustard
Advantages of mixed cropping:
1. It reduces the risk of all crops failing due to uncertain rainfall. If one crop fails, the farmer can still harvest the other.
2. Farmers can get a variety of products, like cereals, pulses, vegetables, or animal feed, to meet their family's needs or the farm's requirements. This diversity ensures a more stable income.
In simple words: Mixed cropping means growing different crops together on the same land. It helps farmers reduce risk from bad weather and get different kinds of food.

🎯 Exam Tip: Define mixed cropping clearly, provide examples of crop combinations, and explain how it contributes to risk reduction and diversified yield.

Question 31. What is sustainable agriculture? Describe the various methods of sustainable agriculture.
Answer: Sustainable agriculture is a way of managing resources to meet human needs for food while also protecting natural resources and using renewable ones. It aims to achieve a balance between farming and the environment.
Various methods of sustainable agriculture include:
1. Mixed farming: This involves growing crops, horticulture (gardening), and raising farm animals, poultry, and pigs together.
Types of mixed crop farming are:
* Food-fodder (e.g., growing food crops with animal feed crops)
* Horticulture-pastoral (e.g., growing fruits/vegetables with animal grazing)
* Agro-forestry (e.g., planting trees with crops)
* Mixed cropping-cereal crops and dairy animals
Mixed cropping, which is growing two or more crops at the same time on the same piece of land, is a key practice.
Some mixed cropping practices are:
(a) Soybean + Pigeon pea
(b) Wheat + Mustard
Advantages of mixed cropping:
(a) The risk of total crop failure due to uncertain monsoon is reduced.
(b) Farmers tend to harvest a variety of produce, such as cereals, pulses, vegetables, or fodder, to meet the various requirements of the family or of agricultural farms.
2. Crop rotation: This is another method of crop production that ensures high yields. Crop rotation means growing different crops in a planned sequence on a piece of land. Depending on the length of the rotation, two or three crops can be grown in one year.
Advantages of crop rotation:
(a) Crop rotation helps to refill the soil's fertility.
(b) It boosts overall production by making the soil more fertile.
(c) It stops diseases and pests from building up in specific crops.
(d) It prevents certain nutrients from being used up too much.
Examples of crop rotation:
1. One-year rotation: Rice – Wheat; Maize – Mustard.
2. Two-year rotation: Maize – Potato; Sugarcane – pea.
3. Three-year rotation: Rice, Wheat-Mung, Mustard, Sugarcane, Burseem.
In simple words: Sustainable agriculture means growing food in a way that protects nature and uses resources wisely for a long time. Methods include mixed farming (growing crops and raising animals together) and crop rotation (changing crops in a field each season).

🎯 Exam Tip: Define sustainable agriculture in terms of resource management and conservation. For methods, clearly describe mixed cropping and crop rotation, including their specific advantages and examples.

Question 32. Name the products formed by Fishery? Describe the steps of fishery?
Answer: Fishery involves the large-scale management of fish under controlled conditions. India is a major fish-producing country, with freshwater fish production being higher than marine (saltwater) fish production. Fish farming (pisciculture) mainly aims to produce fish for food and create job opportunities.
Products formed by fishery: The primary product is fish for consumption. Fish oil is also extracted, used for nutritional supplements and other industrial purposes. Fish meal, made from processing fish, is used as animal feed.
Steps of Pisciculture:
1. Construction of pond: A suitable pond or tank is needed for pisciculture. It should be built on land with clay soil, allowing sunlight to reach the bottom. Proper inlet and outlet for water are important.
2. Food material for fishes: Fish require two types of food:
* Natural food: This includes small aquatic plants and animals. To ensure a continuous supply, bio-fertilizers and bird droppings are added. Lime (CaO) is also added to reduce water acidity.
* Artificial food: This is needed for fast fish growth and includes crushed grains, powdered wheat, soybean, yeast, and rice bran.
3. Removal of fishes from a pond: Fish are harvested once a year. It's important not to remove all fish; partial removal helps increase fish production. Harvesting should preferably be done early in the morning.
4. Precautions of pisciculture:
* Water pollution greatly harms fish, so the pond must be cleaned regularly, and unwanted plants removed. Maintaining water quality is crucial for a successful fishery.
In simple words: Fishery produces fish for food, oil, and animal feed. The steps involve building a pond, feeding the fish natural and artificial food, harvesting them carefully once a year, and keeping the pond clean to prevent pollution.

🎯 Exam Tip: List the primary products and then outline the sequential steps of pisciculture, emphasizing the importance of pond management and feeding.

Question 33. What is Irrigation? Describe the various modern systems of Irrigation?
Answer: Irrigation is the process of supplying water to crop plants in fields using methods like canals, reservoirs, wells, and tube-wells. This is essential for crop growth, especially in areas with uncertain rainfall.
Irrigation depends on two factors:
1. Crop-based irrigation: This considers the specific water needs of different crop plants.
2. Soil-based irrigation: This considers the type of soil in the fields, as different soils retain water differently.
The various irrigation systems in India are as follows:
Common methods include wells, tube wells, pumps, canals, tanks, river-valley systems, and river-lift systems. Irrigation is vital at various stages of crop production, such as sowing, tilling, flowering, and fruiting.
(a) Wells: Wells are dug in places with enough groundwater.
These are of two types:
1. Dug wells: These wells have their bottom below the groundwater table, allowing water to collect from the surroundings. Water is lifted for irrigation using mechanical methods like Persian wheels, operated by bullocks, horses, and camels.
2. Tube wells: These are very deep wells. Water is lifted using diesel or electric pumps.
(b) Tanks: These are small storage areas that collect runoff water from surrounding areas. Small dams are built below these areas to control water flow for agriculture.
(c) Canal system: Canals typically get water from large rivers. Gates at the canal mouth regulate water flow. A canal system includes branch canals, distributaries, or field channels that irrigate fields. A rotation system is followed to ensure all farmers get water for their fields.
(e) River lift system: Water is directly lifted from a river to irrigate nearby fields. This method is used when there isn't enough water in canals or when river reservoirs release insufficient water.
(f) Sprinkler irrigation system: This system is used in canal-irrigated areas of states like Haryana, Rajasthan, and Madhya Pradesh. Drip irrigation, another modern system, is used in Maharashtra, Karnataka, Andhra Pradesh, Odisha, and Tamil Nadu. This technology, often supported by Israeli technical expertise and Indian agricultural research institutes, helps cultivate various crops like roses, tomatoes, and capsicum efficiently.
In simple words: Irrigation is how we give water to crops using things like wells, canals, and tanks. Modern ways include sprinkler and drip systems that save water. The choice of system depends on the crop and soil type.

🎯 Exam Tip: Start with a clear definition of irrigation. Then, categorize the systems (e.g., traditional vs. modern, source-based) and describe at least three key methods with their characteristics.

Question 34. Describe the various aims of improved cropping?
Answer: The various aims of improved cropping are:
1. To increase productivity: The main goal is to get more yield from crops by developing high-yielding varieties.
2. To improve resistance: Plant crops are often affected by living factors like diseases, insects, pests, and nematodes, as well as non-living factors like drought, waterlogging, salinity, heat, and cold. Improved cropping aims to make plants stronger against these stresses.
3. To enhance economic value and quality: This includes improving the quality of pulses (e.g., protein content), oilseeds (e.g., oil quality), and vegetables/fruits (e.g., shelf life).
4. To develop photo-insensitive and thermo-insensitive varieties: Varieties that are not affected by changes in light and temperature can be grown in larger areas, making them more adaptable.
5. To stabilize crop production: Developing improved varieties helps maintain stable crop production even under different environmental conditions.
6. To develop desired agronomic traits: This involves selecting for traits that give higher yields, such as high tillering (more stems) and profuse branching in fodder crops, or dwarfness in cereals to prevent lodging (plants falling over).
Examples of high-yielding wheat varieties include: Sonara 64, Hira, Moti, Kalyan Sona, and Sharbati Sonara.
High-yielding paddy (rice) varieties include: Pusa 205, IR 8, Padma, and Jaya.
In simple words: Improved cropping aims to get more food from plants, make them stronger against diseases and bad weather, improve their quality, and help them grow well in different places and conditions.

🎯 Exam Tip: List the aims clearly and provide specific examples of crop varieties or traits that illustrate each aim.

Question 35. What is water pollution? Describe its various sources and harmful effects.
Answer: Water pollution is the contamination of water bodies with harmful chemicals, waste, or radiation, making it unsafe and unusable. This can harm both humans and aquatic ecosystems.
In simple words: Water pollution is when water becomes dirty and harmful because of chemicals, garbage, or other bad things mixed in it.

🎯 Exam Tip: Define water pollution clearly and ensure your answer mentions both its causes and the negative impacts on living beings and the environment.

Natural Resources and Agriculture Additional Questions Solved

Multiple Choice Questions (MCQs)

Question 1. The compound responsible for the depletion of ozone layer is-
(A) Sulphur dioxide
(B) Chlorofluoro carbon
(C) Alkyl halide
Answer: (B) Chlorofluoro carbon
In simple words: Chlorofluorocarbons, or CFCs, are chemicals that break down the ozone layer high above the Earth. This layer protects us from harmful sun rays.

🎯 Exam Tip: Remember that CFCs were widely used in refrigerants and aerosols before their harmful effects on the ozone layer were discovered.

Question 2. The disease caused by the depletion of ozone layer is-
(A) Typhoid
(B) Kidney trouble
(C) Malaria
(D) Pulmonary disease
Answer: (D) Pulmonary disease
In simple words: When the ozone layer gets thinner, more harmful UV rays reach us. These rays can cause skin cancer, eye problems like cataracts, and also weaken our immune system, making us more prone to lung diseases.

🎯 Exam Tip: Focus on direct health impacts of increased UV radiation, such as skin cancer and eye damage, and general immune system weakening.

Question 3. Which gas is present in the air in the highest proportion?
(A) Oxygen
(B) Nitrogen
(C) Carbon dioxide
(D) Argon
Answer: (B) Nitrogen
In simple words: Nitrogen makes up the biggest part of the air we breathe. It's about 78% of the atmosphere.

🎯 Exam Tip: Know the approximate percentages of the major gases in Earth's atmosphere: Nitrogen (~78%), Oxygen (~21%), Argon (~0.9%), Carbon Dioxide (~0.04%).

Question 4. The main cause of a cough, asthma and tuberculosis is-
(A) Air pollution
(B) Water pollution
(C) Noise pollution
(D) All of the options
Answer: (A) Air pollution
In simple words: When the air is dirty with smoke and bad particles, it can make people cough and get breathing problems like asthma and even tuberculosis.

🎯 Exam Tip: Always link respiratory illnesses directly to air pollution, as airborne particles and gases directly affect the lungs and airways.

Question 5. Which is helpful in checking air pollution-
(A) Animals
(B) Factories
(C) Means of Transport
(D) Trees
Answer: (D) Trees
In simple words: Trees are very good at cleaning the air. They take in bad gases like carbon dioxide and give out oxygen, which helps reduce air pollution.

🎯 Exam Tip: Remember that trees act as natural filters, absorbing pollutants and producing oxygen, making them crucial for air quality improvement.

Question 6. The pollutant which dissolves in rain water to form acid rain is-
(A) Carbon monoxide
(B) Sulphur dioxide
Answer: (B) Sulphur dioxide
In simple words: When chemicals like sulphur dioxide go into the air, they mix with rainwater. This makes the rain acidic, which is bad for buildings and nature.

🎯 Exam Tip: Key pollutants causing acid rain are sulphur dioxide and nitrogen oxides, which react with water, oxygen, and other chemicals to form sulfuric and nitric acids.

Question 7. The purest form of water is-
(A) distilled water
(B) sea water
(C) rain water
(D) well water
Answer: (C) rain water
In simple words: Rainwater is naturally distilled, meaning it's very pure before it touches the ground and picks up other things.

🎯 Exam Tip: Understand that rainwater is pure because it forms from water vapor, leaving impurities behind, but it can pick up pollutants from the atmosphere as it falls.

Question 8. The improved variety of rice is-
(A) Kranti
(B) Pusa Basmati
(C) Pusa Jwala
(D) Pusa Bold"
Answer: (B) Pusa Basmati
In simple words: Pusa Basmati is a well-known kind of rice that has been improved. It is famous for its long grains and pleasant smell.

🎯 Exam Tip: When identifying improved crop varieties, look for names that are commonly associated with high-yield or specific desirable traits like Basmati's aroma.

Question 9. Plants get hydrogen from-
(A) Air
(B) Water
(C) Soil
(D) Sun
Answer: (B) Water
In simple words: Plants take in water, and from that water, they get the hydrogen they need for growth and making food through photosynthesis.

🎯 Exam Tip: Recall the components of photosynthesis; water (\( \text{H}_2\text{O} \)) is the source of hydrogen for glucose formation.

Question 10. Out of the following, which is a micronutrients for plants-
(A) Nitrogen
(B) Boron
(C) Phosphorus
(D) Potassium
Answer: (B) Boron
In simple words: Boron is a very tiny but important food for plants. They only need a small amount of it to grow well, unlike bigger foods like nitrogen or phosphorus.

🎯 Exam Tip: Distinguish between macronutrients (needed in large amounts like N, P, K) and micronutrients (needed in small amounts like Boron, Zinc, Manganese).

Question 11. The organism which prepare vermi- compost is-
(A) Earthworm
Answer: (A) Earthworm
In simple words: Earthworms are like tiny farmers that eat waste from plants and animals. They then produce a rich soil called vermicompost, which is great for growing plants.

🎯 Exam Tip: Remember that vermicomposting is an eco-friendly method of composting using earthworms to break down organic matter into nutrient-rich humus.

Question 12. One of the following is a variety of wheat-
(A) HD - 2687
(B) Ganga-S
(C) Vikram
(D) PNR-S91-18
Answer: (A) HD - 2687
In simple words: HD - 2687 is a type of wheat plant. It is an improved variety chosen for good growth and yield.

🎯 Exam Tip: Familiarize yourself with common high-yielding varieties (HYV) of staple crops in your region, as they are often tested in exams.

Question 13. When two or more crops are grown in the field in succession, the practice is called-
(A) Multiple cropping
(B) Mixed cropping
(C) Mono cropping
(D) None of the options
Answer: (A) Multiple cropping
In simple words: Multiple cropping means growing different crops one after another on the same piece of land within a year. This helps farmers get more harvests from their field.

🎯 Exam Tip: Distinguish multiple cropping (sequence of crops) from mixed cropping (simultaneous growth of different crops in the same field).

Question 14. The HYV of wheat is-
(A) Pusa Basmati
(B) Vikas
(C) C - 306
(D) Navjot
Answer: (C) C - 306
In simple words: C - 306 is a kind of wheat that gives a very good yield. Farmers choose it to grow a lot of wheat.

🎯 Exam Tip: High Yielding Varieties (HYV) are important for increasing food production and are developed through breeding to have better output and resistance.

Question 15. Main cereal crop of our country
(A) Rice
(B) Wheat
(C) Maize
(D) Millet
Answer: (B) Wheat
In simple words: Wheat is one of the most important cereal crops grown and eaten in many parts of our country. It is a main food source for many people.

🎯 Exam Tip: Know the major food crops of India, such as wheat and rice, and their regional importance.

Natural Resources and Agriculture Very Short Answer Type Questions

Question 2. Name a disease caused by coal dust?
Answer: Lung cancer. Breathing in coal dust for a long time can damage the lungs, leading to serious diseases like black lung disease, which can increase the risk of lung cancer.
In simple words: Coal dust can cause lung cancer.

🎯 Exam Tip: Recognize that inhaling fine particulate matter, especially from industrial sources like coal dust, is a significant risk factor for various respiratory diseases including cancer.

Question 3. Which gases cause eye burn?
Answer: Sulphur dioxide, Chlorine, and Ammonia. These gases are irritants that can cause burning sensations and irritation in the eyes when present in high concentrations.
In simple words: Sulphur dioxide, chlorine, and ammonia gases can make your eyes burn.

🎯 Exam Tip: Identify common irritant gases that can cause immediate discomfort or harm to mucous membranes like those in the eyes.

Question 4. Name the class of compounds which destroy the atmospheric ozone layer.
Answer: Chlorofluoro carbons. These compounds release chlorine atoms in the stratosphere, which then react with and break down ozone molecules.
In simple words: Chemicals called chlorofluorocarbons destroy the ozone layer in the air.

🎯 Exam Tip: Remember CFCs are the primary culprits for ozone depletion due to their stable nature and ability to release chlorine radicals in the upper atmosphere.

Question 5. What diseases are produced by dust particles?
Answer: Coryza, cough, asthma and tuberculosis. Fine dust particles can irritate the respiratory system, leading to allergic reactions, inflammation, and worsening pre-existing conditions.
In simple words: Dust particles can cause colds (coryza), coughs, asthma, and tuberculosis.

🎯 Exam Tip: Relate dust pollution to respiratory issues, as inhaled particles can trigger allergies, inflammation, and exacerbate lung conditions.

Question 6. What is air pollution?
Answer: Air pollution is any harmful change in the natural composition of air that negatively affects living beings. This can involve adding unwanted gases or particles to the air.
In simple words: Air pollution happens when bad things are added to the air, making it dirty and harmful for living things.

🎯 Exam Tip: A good definition of pollution should always include both the "change in composition" and the "undesirable/harmful effect on living beings."

Question 7. Name two air pollutants which cause acid rain.
Answer:
(a) Sulphur dioxide (\( \text{SO}_2 \))
(b) Nitrogen dioxide (\( \text{NO}_2 \)) Both of these gases react with water in the atmosphere to form strong acids, which then fall as acid rain.
In simple words: Sulphur dioxide and nitrogen dioxide are two gases that make rain acidic.

🎯 Exam Tip: The main culprits for acid rain are oxides of sulfur and nitrogen, often released from industrial processes and vehicle exhaust.

Question 9. What gases are emitted by burning of petrol?
Answer: Carbon monoxide (CO), carbon dioxide (\( \text{CO}_2 \)) and nitrogen oxides (\( \text{N}_2\text{O} \), \( \text{NO}_2 \)) are emitted by burning of petrol. These gases contribute to air pollution and climate change.
In simple words: Burning petrol releases gases like carbon monoxide, carbon dioxide, and nitrogen oxides.

🎯 Exam Tip: List the primary combustion products of fossil fuels, focusing on those that are air pollutants or greenhouse gases.

Question 10. What is water pollution?
Answer: Water pollution is the contamination of water with harmful chemicals and radiation. This makes the water unsafe for use and harms aquatic life.
In simple words: Water pollution means water becomes dirty and harmful because of bad chemicals or radiation.

🎯 Exam Tip: Define water pollution by emphasizing the addition of contaminants that degrade water quality and make it unfit for its intended use.

Question 11. Name four diseases caused by water pollution.
Answer:
1. Cholera
2. Dysentery
3. Typhoid
4. Jaundice. These are all waterborne diseases, meaning they spread through contaminated drinking water.
In simple words: Cholera, dysentery, typhoid, and jaundice are four illnesses you can get from polluted water.

🎯 Exam Tip: Focus on waterborne diseases that are easily transmissible through contaminated water sources, especially those affecting the digestive system.

Question 12. Explain why fishes in some river, pond or along sea shore are sometimes found dead.
Answer: Toxic chemicals present in waste material thrown from factories and industries into river water, on a large scale, kill the fishes. These chemicals reduce the oxygen in the water, making it hard for fish to breathe and survive.
In simple words: Fish die in rivers and ponds when factories dump poisonous chemicals into the water, which makes the water unhealthy for them.

🎯 Exam Tip: The death of aquatic life due to pollution is often linked to depletion of dissolved oxygen caused by organic waste or the direct toxicity of industrial chemicals.

Question 13. Name the two gases which together constitute 99% of the atmosphere.
Answer: Oxygen (20.946%) and nitrogen (78.084%). Together, these two gases make up the vast majority of Earth's atmosphere, which is essential for life.
In simple words: Oxygen and nitrogen are the two main gases that make up almost all of our atmosphere.

🎯 Exam Tip: Remember the approximate percentages: Nitrogen is about 78% and Oxygen is about 21%, together forming almost 99% of the atmosphere.

Question 14. What is the percentage of oxygen in gases present in the atmosphere?
Answer: The percentage of oxygen in gases present in the atmosphere is approximately 20.95% (often rounded to 21%). This amount is vital for most living organisms to breathe.
In simple words: Oxygen makes up about 21% of the air around us.

🎯 Exam Tip: State the precise percentage of oxygen to show accuracy, even if a rounded figure is acceptable in general discussions.

Question 15. What is Smog?
Answer: Smog is a combination of smoke, water droplets of fog and fumes discharged into air from homes, factories and automobiles. It creates a thick, hazy layer that reduces visibility and is harmful to health.
In simple words: Smog is like dirty fog made from smoke, mist, and fumes from cars and factories.

🎯 Exam Tip: Define smog as a type of intense air pollution, specifically a mixture of smoke and fog, often intensified by vehicle emissions.

Question 16. Write the name of the gas produced in Mathura Refineries which can damage the great historical monument, Taj Mahal.
Answer: Sulphur dioxide gas. This gas reacts with atmospheric moisture to form sulfuric acid, which then corrodes the marble of the Taj Mahal.
In simple words: Sulphur dioxide from Mathura Refineries can harm the Taj Mahal.

🎯 Exam Tip: Connect industrial emissions, particularly sulfur dioxide, directly to acid rain and its corrosive effects on monuments like the Taj Mahal.

Question 17. Write the name of the improved variety of wheat?
Answer: HD 2687. This is a high-yielding variety of wheat, known for its good productivity and suitability for certain regions.
In simple words: HD 2687 is a better kind of wheat plant.

🎯 Exam Tip: Listing specific high-yielding varieties (HYV) demonstrates detailed knowledge of agricultural practices.

Question 18. Name the manure which is formed with the help of earthworm.
Answer: Vermicompost. Earthworms break down organic waste into a rich, nutrient-filled soil amendment.
In simple words: Vermicompost is made by earthworms.

🎯 Exam Tip: Understand that vermicompost is a valuable organic fertilizer produced through the decomposition process carried out by earthworms.

Question 19. Mention the best way to protect plants from the virus.
Answer: The best way to protect plants from virus disease is to grow TMV resistant varieties. Infected plants should also be removed and burnt from the field immediately to prevent spread.
In simple words: To protect plants from viruses, grow kinds that can fight off the virus, and burn any sick plants right away.

🎯 Exam Tip: Emphasize preventive measures like using resistant varieties and hygienic practices (removing infected plants) as the most effective ways to manage viral plant diseases.

Question 20. How a pathogen entry can be prevented in a crop field?
Answer: Pathogen entry can be prevented by using proper preventive measures. This includes selecting the optimum time for cropping, using pest and disease resistant hybrid varieties, practicing crop rotation, and maintaining clean cultivation. These methods reduce the chances of pathogens establishing and spreading.
In simple words: We can stop germs from entering crop fields by planting at the right time, using strong plant types, changing crops often, and keeping the farm clean.

🎯 Exam Tip: List a range of integrated pest management strategies, focusing on prevention through genetic resistance, environmental control, and cultural practices.

Question 21. Define Inter-cropping?
Answer: Inter-cropping is the practice of growing two or more crops simultaneously in the same field, but in a definite pattern. For example, a few rows of one crop might alternate with a few rows of a second crop. This method can maximize land use and reduce risk.
In simple words: Inter-cropping is growing two or more different crops together in the same field in neat rows.

🎯 Exam Tip: Highlight the "definite pattern" as the key differentiating factor for inter-cropping compared to general mixed cropping.

Question 22. What is sustainable agriculture?
Answer: Sustainable agriculture refers to managing resources successfully to meet human needs while also conserving natural resources and using renewable resources. It aims for long-term productivity without harming the environment.
In simple words: Sustainable agriculture means farming in a way that provides food for people now without hurting the environment, so there's enough for the future too.

🎯 Exam Tip: Define sustainable agriculture by combining the concepts of meeting current needs, conserving resources, and ensuring long-term ecological balance.

Question 23. What do you understand by rotation of crops.
Answer: Rotation of crop is the repeated cultivation of a cereal crop and a legume crop in successive seasons. This practice helps maintain soil fertility and reduce pest problems.
In simple words: Crop rotation means growing different types of crops one after another on the same field, like a cereal crop followed by a bean crop.

🎯 Exam Tip: Explain crop rotation by emphasizing the sequence of different crop types to improve soil health and manage pests naturally.

Question 24. What are primary nutrients?
Answer: Primary nutrients are the most important minerals required in significant amounts for plant growth. These essential elements are Nitrogen, Phosphorus, and Potassium, often referred to as NPK.
In simple words: Primary nutrients are the main foods plants need a lot of, like nitrogen, phosphorus, and potassium, to grow big and strong.

🎯 Exam Tip: Always remember NPK (Nitrogen, Phosphorus, Potassium) as the three primary macronutrients crucial for plant development.

Question 25. Write one advantage of crop rotation.
Answer: Crop rotation helps to reduce the attraction of pathogens and pests, controls weeds, and improves soil fertility. By changing crops, diseases and pests that prefer a specific crop don't build up in the soil.
In simple words: One good thing about changing crops is that it helps stop plant diseases and pests, and it makes the soil healthier.

🎯 Exam Tip: Focus on how crop rotation breaks disease cycles and naturally replenishes soil nutrients, reducing the need for artificial interventions.

Question 26. What are weedicides? Name one weedicide.
Answer: Weedicides are chemical substances used to kill unwanted plants, called weeds, in crop fields. An example of a weedicide is 2,4-D (2,4-Dichlorophenoxy acetic acid), which specifically targets broadleaf weeds.
In simple words: Weedicides are chemicals that kill weeds. An example is 2,4-D.

🎯 Exam Tip: Mentioning a specific example like 2,4-D, along with its function, shows a deeper understanding of weed control agents.

Question 27. Write the name of two fungal diseases of plants.
Answer:
(a) Late blight of potato.
(b) Green ear disease of Bajra. These diseases are caused by different types of fungi and can significantly harm crop yields.
In simple words: Late blight in potatoes and green ear disease in bajra are two plant sicknesses caused by fungus.

🎯 Exam Tip: Be able to name common plant diseases and identify their causal agents (e.g., fungi, bacteria, viruses).

Natural Resources and Agriculture Short Answer Type Questions.

Question 1. What are the different kinds of environmental pollution?
Answer: The different kinds of environmental pollution are:
1. Water pollution
2. Air pollution
3. Land pollution
4. Noise pollution
5. Radioactive pollution
6. Thermal pollution. Each type harms the environment in unique ways, affecting living organisms and ecosystems.
In simple words: There are many types of pollution, like water, air, land, noise, radioactive, and heat pollution.

🎯 Exam Tip: Ensure you can list the main types of environmental pollution and briefly describe what each entails.

Question 2. Which sources emit carbon dioxide in the atmosphere?
Answer: Carbon dioxide is released into the atmosphere from several sources:
1. When fossil fuels like wood, coal, and oil are burned in furnaces, carbon dioxide is released.
2. Burning petrol or other fuels in vehicles like cars, trains, ships, and planes discharges carbon dioxide.
3. Living beings also release \( \text{CO}_2 \) into the atmosphere when they respire (breathe out). This gas is a natural part of the carbon cycle but excessive amounts cause problems.
In simple words: Carbon dioxide comes from burning fuels like wood and petrol, and also from living things when they breathe out.

🎯 Exam Tip: Differentiate between natural and anthropogenic sources of carbon dioxide, highlighting combustion of fossil fuels as a major human contribution.

Question 3. Why a long exposure to carbon monoxide is fatal for human beings?
Answer: Carbon monoxide is very dangerous because it binds with haemoglobin in our blood much more easily (about 200 times more) than oxygen. If a person breathes in carbon monoxide for 6 to 8 hours, it forms carboxy-haemoglobin, which means the red blood cells cannot carry oxygen to different parts of the body. This lack of oxygen causes the person to die.
In simple words: Carbon monoxide is deadly because it stops our blood from carrying oxygen to the body, making us suffocate slowly.

🎯 Exam Tip: Explain carbon monoxide's toxicity by focusing on its irreversible binding with haemoglobin, which prevents oxygen transport and leads to suffocation.

Question 5. How noise pollution can be controlled during festivals and social functions?
Answer: To control noise pollution during festivals and social functions, the following measures can be adopted:
1. The use of noise pollution produced by loudspeakers during festivals and social and religious functions should be restricted.
2. Burning of crackers and other fireworks should be strictly prohibited from 10 O'clock at night till 6 O'clock in the morning.
3. Crackers with high sound intensity should not be allowed.
4. Crackers and fireworks should not be allowed near hospitals, educational institutions. By taking these steps, communities can enjoy festivities with less disturbance and health risk.
In simple words: To control noise pollution during festivals, we should limit loudspeakers, stop loud firecrackers at night, and keep noisy events away from quiet places like hospitals.

🎯 Exam Tip: Focus on practical, community-level regulations and responsible behavior as key strategies to mitigate noise pollution from celebratory events.

Question 6. What are macro-nutrients and why are they called macro-nutrients?
Answer: Macronutrients are essential inorganic elements that plants need in larger quantities for their growth and reproduction. They are called macronutrients because plants require them in relatively larger amounts compared to micronutrients. Examples include carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, and calcium.
In simple words: Macronutrients are big food items that plants need a lot of, like nitrogen and potassium, to grow well.

🎯 Exam Tip: Clearly define macronutrients by their quantity requirement (large amounts) and provide examples (N, P, K, Ca, Mg, S).

Question 7. What management practices are common in dairy and poultry farming?
Answer: The principles of feeding, breeding, and health care (weeding out sick animals) are common in both dairy and poultry farming. Additionally, proper shelter with good hygiene, aeration, and lighting is crucial for both types of animals. Providing good living conditions and food helps the animals stay healthy and productive.
In simple words: Both dairy and poultry farms need good food, careful breeding, and healthy living spaces with clean air and light.

🎯 Exam Tip: Focus on the fundamental practices common to animal husbandry: nutrition, genetic improvement, disease control, and environmental management.

Question 8. Why are manures and fertilizers used in fields?
Answer: Manures and fertilizers are used in fields primarily to replenish minerals that get used up by crops or wash away into the soil. Here's why they are important:
1. Manures add small amounts of all minerals to the soil. They improve how well the soil holds water, gets air, and supports helpful tiny organisms that break down heavy minerals.
2. Fertilizers are specific nutrients that contain one or more minerals in a concentrated form. They quickly provide the minerals needed by high-yielding crops. However, they can harm soil structure and pollute crops, soil, groundwater, and nearby water. Using both manure and fertilizer together is very helpful for balanced plant nutrition.
In simple words: Manures and fertilizers are used to give plants the food they need. Manures make the soil healthier overall, while fertilizers give specific nutrients quickly.

🎯 Exam Tip: Differentiate between manure (improves soil structure and provides broad nutrients) and fertilizers (provide concentrated, specific nutrients) and discuss their combined benefits and individual drawbacks.

Question 9. What are the benefits of cattle farming?
Answer: Cattle farmers benefit in many ways:
1. They use cattle for various work purposes in farming, such as ploughing and harrowing fields.
2. They get milk from cattle, which provides daily nutrition.
3. Cattle farming provides extra income from selling milk or other products.
4. Cattle provide manure, which can be used as fertilizer, and fuel (dung cakes). Farming and cattle rearing work together well.
5. They are used to pull carts for moving materials and people. Cattle are a versatile resource for farmers.
In simple words: Cattle farming helps farmers with work like ploughing, gives them milk for food and extra money, provides manure for fields, and helps with transport.

🎯 Exam Tip: List the multiple economic and agricultural benefits of cattle, including draft power, dairy products, manure, and transportation.

Question 10. List out some useful traits in improved crop?
Answer: Useful traits in improved crops include:
1. Higher yield: Crops produce more.
2. Improved nutritional quality: The food from the crop is healthier.
3. Resistance to biotic and abiotic stresses: Crops can fight off diseases, pests, and bad weather.
4. Change in maturity: Crops grow faster or slower as needed.
5. Wide range of adaptability: Crops can grow well in many different places. These traits are selected through careful breeding to make farming more efficient and productive.
In simple words: Good crop traits are things like growing more food, being healthier, fighting off diseases, maturing at the right time, and growing well in many places.

🎯 Exam Tip: Focus on traits that directly contribute to increased agricultural productivity, resilience, and nutritional value.

Question 11. Describe the optimal food requirements of cattle and poultry birds.
Answer: The food needs of cattle and poultry birds change based on their age, health, type of work, and special conditions like lactation (milk production) period. Here's a breakdown:
1. The best food for cattle can be figured out by studying their internal body parts and how they work, as well as the nutrition in their feed and fodder. The amount of milk an animal gives largely depends on what it eats.
2. A young calf needs more food and nutrients than an old cow to grow properly.
3. Poultry birds also need important nutrients like carbohydrates, proteins, and minerals in their feed. For bigger poultry farms, their food often includes mashed cereals such as bajra, wheat, maize, rice, beans, and groundnut cake. Providing the right food ensures their health and productivity.
In simple words: How much food cattle and chickens need changes with their age, health, and how much work they do. Good food makes animals healthy and productive.

🎯 Exam Tip: Emphasize that animal nutrition is not static but depends on physiological state (e.g., growth, lactation, egg-laying) and activity level.

Question 12. Describe the role of fertilisers and irrigation in improving crop yield. Mention any one effect of each if it is used in excess.
Answer: Both fertilisers and irrigation play vital roles in improving crop yield. However, their excessive use can have negative consequences.
**Role of fertilisers:**
1. They provide essential macronutrients like Nitrogen (N), Phosphorus (P), Potassium (K), Sulfur (S), and Magnesium (Mg), and micronutrients like Copper (Cu), Boron (B), and Manganese (Mn) needed for proper growth and development of plants.
2. Fertilisers are easily soluble in water and are quickly absorbed by plants, providing immediate nutrition.
3. They provide these nutrients in specific, measured quantities.
**Role of irrigation:**
1. Irrigation supplies water to specific crops at certain frequencies and quantities; for example, paddy needs a lot of water.
2. It provides the water supply essential for plant life processes, such as photosynthesis.
3. It is applied at specific frequencies and quantities for different soil types; for instance, sandy soils need more frequent irrigation.
**Effect when fertilisers are used in excess:**
Excess nitrogenous fertilisers from the soil can be washed into water bodies like ponds, leading to increased algal growth and oxygen depletion. This process is called eutrophication, which harms aquatic life. Farmers should be careful not to use too much fertilizer.
In simple words: Fertilisers give plants food, and irrigation gives them water, both helping crops grow better. But too much fertiliser can pollute water and cause algae to grow too much, which is bad for fish.

🎯 Exam Tip: When discussing fertilizers and irrigation, always mention their benefits alongside the environmental risks of overuse, like eutrophication for fertilizers.

Question 13. What is the difference between indigenous and exotic breeds? What are the advantages of exotic breeds?
Answer: Indigenous breeds are native to a particular region and are well-adapted to local conditions, while exotic breeds are introduced from other regions or countries, often for specific superior traits. The desirable traits of exotic breeds for commercial production are as follows:
1. Dwarf broiler parent, ideal for commercial chick production.
2. Increased number and quality of chicks.
3. Improvement in hens for egg production, and a reduction in the size of the layer, allowing them to utilize a more fibrous diet made from agricultural by-products.
4. Low maintenance requirements, making them easier to care for.
5. Good tolerance for summer adaptation and high temperatures. These traits make exotic breeds highly valuable in commercial farming.
**Advantages of exotic breeds:**
1. They mature easily, leading to quicker production cycles.
2. They yield more eggs and meat, increasing profitability.
3. They are smaller in size and eat less compared to indigenous varieties, reducing feeding costs.
In simple words: Local breeds are from here, exotic breeds are from other places. Exotic breeds are good because they grow fast, lay more eggs, and need less food, making them useful for big farms.

🎯 Exam Tip: When comparing indigenous and exotic breeds, highlight the adaptation of indigenous breeds to local conditions versus the high productivity/specific traits of exotic breeds for commercial purposes.

Question 14. What is inter-cropping? How does it differ from mixed cropping? State its two advantages?
Answer: Inter-cropping is the process of growing two or more crops simultaneously on the same field in a definite pattern. Typically, a few rows of one crop alternate with a few rows of a second crop. For example, soybean + maize or finger millet (bajra) + cowpea (lobia) are common inter-cropping combinations. This method helps optimize land use and reduce risks.
**Difference between mixed cropping and Inter-cropping are as follows:**

**Advantages of inter-cropping are as follows:**
1. It prevents pests and diseases from spreading to all the plants of one crop in a field. This way, both crops can give better returns.
2. It ensures maximum utilization of the nutrients supplied in the soil. Inter-cropping promotes efficient resource use.
In simple words: Inter-cropping is planting different crops in separate rows on the same field at the same time. This helps stop diseases from spreading and uses all the soil food well. Mixed cropping just mixes seeds together.

🎯 Exam Tip: The key distinction is the "definite pattern" in inter-cropping versus the random mixture in mixed cropping. Emphasize advantages like pest control and efficient resource use.

Question 15. Why should preventive measures and biological control methods be preferred for protecting crops?
Answer: Prevention is always better than cure. Preventive measures and biological control methods are preferred for protecting crop plants because they not only stop stored food materials from spoiling or getting infested by insects, bacteria, and micro-organisms, but also protect crops from harmful chemicals. These chemicals, like some insecticides such as DDT, can be very toxic. Some pesticides can even lead to biomagnification, where they build up in the food chain and become more concentrated at higher levels, harming animals and humans. Biological methods are also eco-friendly, causing less harm to the environment. Choosing these methods helps ensure safer food and a healthier planet.
In simple words: It's better to prevent crop problems and use natural controls because chemicals can be dangerous. Chemicals can poison our food and the environment, but prevention and biological controls are safe and gentle.

🎯 Exam Tip: Highlight the environmental and health benefits of biological control and preventive measures over chemical pesticides, focusing on avoiding toxicity and biomagnification.

Natural Resources and Agriculture Long Answer Type Questions

Question 1. What is sound pollution? What are the different sources of sound pollution? How pollution can be controlled?
Answer: Sound pollution is the production of undesirable, loud, and harsh sound at the wrong place and wrong time. For example, the sound of bus or truck sirens might seem normal on a highway, but near a hospital or school, it becomes noise and causes sound pollution. Any unwanted sound is called noise. The intensity of sound is measured in decibels (dB). Normal conversation is around 30-50 decibels. This type of pollution can seriously affect human health and well-being.
**Following are the sources of sound pollution:**
1. **Sources of sound in homes:** Appliances like air conditioners produce various sounds and noise, contributing to sound pollution within households.
2. **Sources of sound in surroundings:** Loudspeakers used in religious places, during festivals, or public meetings create noise. Exploding crackers, crying hawkers in streets, and fairs also add to sound pollution.
3. **Sources of sound in factories and industries:** Machines in factories make loud, roaring noises that contribute significantly to noise pollution.
4. **Sources of sound due to traffic:** Various automobiles, flying aeroplanes, and railway locomotives all produce unwanted, high-intensity sound, which is a major contributor to urban noise pollution.
**Measures to control noise pollution:**
1. **Noise control in homes:** Proper maintenance and careful use of televisions, radios, transistors, grinders, and desert coolers can reduce noise levels by keeping their volume low.
2. **Noise control on roads:** Vehicles should be properly maintained, and low-sound sirens should be used to control noise pollution. Laws should be enforced to remove noisy vehicles from roads.
3. **Control on noise produced by industries and factories:** Machines should be well lubricated and maintained to reduce noise. Factories should also be located away from residential areas to minimize disturbance.
4. **Trees and plants are good sound absorbers:** Planting trees and plants on both sides of roads can help block sound from reaching homes, educational institutions, and offices.
5. **Public awareness:** People should be informed through newspapers, television, radio, and magazines about the harmful effects of noise on health. This can encourage them to adopt quieter practices. By implementing these measures, communities can significantly reduce sound pollution and create healthier living environments.
In simple words: Sound pollution is loud, unwanted noise. It comes from homes (appliances), outside (loudspeakers, crackers), factories (machines), and traffic (cars, planes). To control it, we should keep home volumes low, maintain vehicles, move factories away from homes, plant trees, and teach people about its dangers.

🎯 Exam Tip: When answering questions on pollution, always define the pollution type, list its sources, and provide actionable control measures, using clear examples.

Question 3. Explain the various methods of crop improvement. Name one improved variety of Rice, Maize, Soybean, Sunflower and Mustard?
Answer: The most important methods to improve crops are:
(1) **Higher yield:** The main goal is to get more produce from crops, like vegetables, grains, and animal feed. Farmers use high-quality seeds of improved varieties for better commercial output.
(2) **Improved quality:** The quality that is important changes with each crop. For example, we look for more protein in pulses, better baking qualities in wheat, good oil content in oil seeds, and longer storage life for fruits and vegetables.
(3) **Photo-insensitivity and thermo-insensitivity:** Many plants are sensitive to natural conditions like light and temperature. Developing crop varieties that are not affected by light and can handle different temperatures helps them grow in more places. For instance, MACS 2469 is a wheat variety that can grow well even in high temperatures.
(5) **Biotic and abiotic resistance:** Crops often face problems like diseases, insects, pests, or tough weather such as drought, extreme heat, or cold. If we create crop varieties that can resist these problems, we can significantly improve how much food we produce. For example, MUW 318 is a high-yielding wheat variety that grows well in new areas like Nilgiri and Palni hills and is resistant to many rust diseases.
(6) **Desirable agronomic traits:** Developing crops with specific desired features helps increase production. For animal feed crops, traits like being tall and having many branches are good. For grains like cereals, being short (dwarf) is better because it prevents the plants from falling over. For example, new varieties of sugarcane like CO 975 and Co 62399 have been developed to grow better in difficult areas, and chickpea varieties like BG 244 and ICC 34 grow upright with many pods.
Some improved varieties of high-yielding crop plants are:
1. Rice - IR 8, Jaya
2. Maize - Ganga 5
3. Mustard - Pusa Gold, Kranti
4. Soybean - PK 262
5. Sunflower - BSH 1
In simple words: Crop improvement means making plants better. We aim for more produce, better quality, and stronger plants that can fight off diseases and bad weather. We also choose plants with useful traits like being tall for animal feed or short for grains. There are many special types of seeds for different crops now.

🎯 Exam Tip: When listing varieties, remember to match each crop with its correct improved names. For methods, provide a short explanation for each, focusing on the benefit.

Question 4. (a) What are the causes of crop disease? (b) Explain the types of crop diseases. (c) How does crop disease can be controlled?
Answer:
(a) **Causes of crop disease:** Crop diseases happen when tiny living organisms like bacteria, fungi, and viruses find the right conditions to grow and multiply. They spread and infect crop plants, causing them to become sick.
(b) **Types of crop diseases:** Diseases are classified based on how they spread to plants:
* **Seed-borne diseases:** These diseases are carried and spread through the seeds of the plants themselves. For instance, 'leaf spot of rice' is a disease that spreads this way.
(c) **How crop disease can be controlled:** To manage crop diseases effectively:
* Diseases that spread through seeds or soil can be controlled by treating the seeds or the soil with protective substances.
* Diseases that spread through the air can be managed by spraying a fungicidal solution on the infected parts of the plants.
In simple words: Plant diseases are caused by tiny germs like bacteria and viruses when they find good places to grow. Some diseases come from bad seeds, while others float in the air. We can stop them by treating seeds and soil or by spraying special liquids on sick plants.

🎯 Exam Tip: Remember the three main parts of this question: causes, types, and control methods. Provide a specific example for each type of disease to show clear understanding.