Natural Resources - MCQ Test (22-11-2017) - Class 9 MCQ

Movement of air occurs due to difference in air pressure of two places. It is not influenced by rotation of earth, vaporization and condensation of water vapour and topography over which passes.

Overgrazing  deforestation causes loosening of soil particles of top soil which enhances soil erosion 

Water pollution is the addition of undesirable substances into water bodies. It can result from various sources such as industrial waste, agricultural runoff, and sewage discharge. The contaminants introduced into the water can have harmful effects on the environment and human health.

Causes of Water Pollution:

• Industrial Waste: Discharge of chemicals, heavy metals, and toxins from industries can contaminate water bodies.


• Agricultural Runoff: Pesticides, fertilizers, and animal waste from agricultural activities can enter water sources, causing pollution.


• Sewage Discharge: Improperly treated or untreated sewage can release pathogens and pollutants into water bodies.


• Oil Spills: Accidental release of oil into water bodies can have catastrophic effects on aquatic life.


• Urban Runoff: Stormwater runoff from urban areas can carry pollutants like oil, heavy metals, and trash into water bodies.


• Improper Waste Disposal: Dumping of waste materials, including plastics and chemicals, into water sources contributes to pollution.

Effects of Water Pollution:

• Ecological Damage: Water pollution can harm aquatic ecosystems, leading to the decline of fish and other aquatic species.


• Human Health Risks: Contaminated water can cause waterborne diseases, including diarrhea, cholera, and dysentery.


• Loss of Biodiversity: Pollution can disrupt the balance of aquatic ecosystems, resulting in the loss of biodiversity.


• Economic Impact: Water pollution can negatively affect industries such as fishing, tourism, and agriculture, leading to economic losses.


• Drinking Water Contamination: Polluted water sources can contaminate drinking water supplies, posing a risk to human health.

Prevention and Control of Water Pollution:

• Treatment of Industrial Wastewater: Industries should implement proper treatment processes to remove pollutants from their wastewater before discharging it into water bodies.


• Proper Waste Disposal: Waste materials should be disposed of correctly, following regulations and guidelines to prevent pollution.


• Agricultural Best Practices: Farmers can adopt sustainable agricultural practices to minimize the use of pesticides and fertilizers, reducing agricultural runoff.


• Sewage Treatment: Proper treatment of sewage is essential to remove harmful pathogens and pollutants before releasing it into water bodies.


• Environmental Education and Awareness: Spreading awareness about the importance of clean water and promoting responsible water usage can help prevent water pollution.


• Regulatory Measures: Governments should enforce strict regulations and policies to control pollution sources and ensure compliance with environmental standards.

In conclusion, water pollution is the addition of undesirable substances into water bodies, which can have detrimental effects on the environment, aquatic life, and human health. It is crucial to take preventive measures and implement proper waste management practices to minimize water pollution and protect our water resources.

Water Cycle Steps:
The water cycle, also known as the hydrologic cycle, is the continuous movement of water on, above, and below the Earth's surface. It involves several important steps.
Evaporation:
- Water from oceans, lakes, rivers, and other water bodies is heated by the sun and turns into vapor or steam.
- This vapor rises into the atmosphere.
Transpiration:
- Plants absorb water from the ground through their roots.
- This water moves up through the plant and evaporates from the leaves as water vapor.
- This vapor also enters the atmosphere.
Precipitation:
- Water vapor in the atmosphere condenses into tiny water droplets or ice crystals.
- These droplets or crystals combine to form clouds.
- When the clouds become too heavy, the water falls back to the Earth's surface as precipitation.
- Precipitation can take the form of rain, snow, sleet, or hail.
Condensation:
- Water vapor in the atmosphere cools down and changes back into liquid form.
- This process is called condensation.
- Condensation occurs when warm air rises and cools, or when moist air comes into contact with a colder surface.
Summary:
- The water cycle consists of the following steps: evaporation, transpiration, precipitation, and condensation.
- Evaporation and transpiration involve the conversion of water into vapor or steam and its entry into the atmosphere.
- Precipitation occurs when the water vapor in the atmosphere condenses and falls back to the Earth's surface as rain, snow, sleet, or hail.
- Condensation is the process of water vapor changing back into liquid form.
- All of these steps are interconnected and essential for the continuous movement of water on Earth.

The envelop of air surrounding the surface of planets is called atmosphere. Earth, Venus and Mars all these planets have their own atmosphere.

Lichen releases hydrolytic enzymes which breaks the rocks into small particles
Frost are the ice crystal which get deposited on the rocks which help in contraction of rocks due to which cracks formed on it.

Explanation:
The correct answer is option C: (a) and (c) are correct.
Here is a detailed explanation:
1. Eco-friendliness: The use of large amounts of fertilizers and pesticides is not eco-friendly. Fertilizers and pesticides contain chemicals that can have harmful effects on the environment. They can pollute water sources, harm beneficial insects and wildlife, and contribute to air pollution.
2. Field barrenness: The use of large amounts of fertilizers and pesticides can lead to the turning of fields barren after some time. Continuous use of these chemicals can deplete the nutrients in the soil, making it less fertile and productive. This can result in reduced crop yields and the need for even more fertilizers and pesticides to maintain productivity.
3. Natural replenishment of soil: The use of large amounts of fertilizers and pesticides does not maintain the natural replenishment of the soil. Fertilizers provide nutrients to the soil, but they do not replace the natural processes of nutrient cycling and organic matter decomposition that occur in healthy, balanced ecosystems. Pesticides can also harm beneficial soil organisms that contribute to soil health and fertility.
4. Soil fertility destruction: The use of large amounts of fertilizers and pesticides can destroy the soil fertility. Over-reliance on synthetic fertilizers can lead to imbalances in soil nutrients and pH levels, as well as the accumulation of salts and other chemicals. This can negatively impact soil structure, microbial activity, and nutrient availability, ultimately reducing soil fertility.
In conclusion, the use of large amounts of fertilizers and pesticides is not eco-friendly, can turn fields barren, does not maintain the natural replenishment of the soil, and can destroy soil fertility.

All form of life requires food, water, favourable temperature to sustain life. Food provides energy for carrying out various metabolic activities. Water and temperature provide optimal condition inside the body.

The atmosphere of Venus and Mars planet consists of mainly carbon dioxide gas. Due to presence of higher amount of carbon dioxide gas temperature increases very high during day and low during night.

Those substances that can be broken down into simpler forms by action of microbes are called bio-degradable substance, leaves, fruits and vegetables and mud are biodegradable substance. Plastic cannot be broken into simpler forms so, it is an example of non-biodegradable pollutant.

Method used to control pollution:

Installation of gobar gas plant:

• Installation of gobar gas plant is an effective method to control pollution.


• Gobar gas plants use organic waste such as cow dung to produce biogas for cooking and electricity generation.


• By using cow dung as a renewable energy source, gobar gas plants reduce the dependency on fossil fuels like coal and petrol.


• This helps in reducing air pollution and greenhouse gas emissions.

Dumping of non-biodegradable waste in low-lying areas:

• Dumping of non-biodegradable waste in low-lying areas is not a method used to control pollution.


• It is an improper waste disposal method that can lead to environmental pollution and degradation.


• Non-biodegradable waste should be properly segregated, recycled, or disposed of in designated landfill sites.

Use of coal and petrol:

• The use of coal and petrol is not a method used to control pollution.


• Coal combustion releases harmful pollutants such as sulfur dioxide, nitrogen oxides, and particulate matter, contributing to air pollution and climate change.


• Petrol combustion in vehicles also emits pollutants such as carbon monoxide, nitrogen oxides, and volatile organic compounds, which are harmful to human health and the environment.

Conversion of organic waste and fecal material into compost:

• Conversion of organic waste and fecal material into compost is an effective method to control pollution.


• Composting is a natural process that transforms organic waste into nutrient-rich compost, which can be used as a soil conditioner.


• This reduces the amount of organic waste going to landfills, preventing the release of methane, a potent greenhouse gas.


• Composting also improves soil health, reduces the need for chemical fertilizers, and promotes sustainable agriculture.

Therefore, the correct answer is option C: (a) and (d) are correct. The installation of gobar gas plants and the conversion of organic waste and fecal material into compost are methods used to control pollution.

The sun is an example of non-conventional source of energy which can be used to produce heat energy; electrical energy etc. coal, petroleum and wood are conventional sources of energy.

In atmosphere oxygen is found in form of ozone (O₃) and oxygen(O₂). Oxygen is found in lower layers and ozone in ozonosphere.

Water pollution is the addition of harmful substance in water that changes its chemical, Physical and biological properties. Water pollution causes eutrophication, pesticidal toxicity and bio magnifications.

During water cycle, water exists in all three states, solid, liquid and Gas. Due to evaporation and transpiration, liquid water changes into water vapour. On cooling, water vapour converts into solid state during cloud formation.

DDT is a non-biodegradable pollutant. Red data book provides information regarding threatened species of plant and animals. Jaldpara sanctuary is situated in West Bengal. Chinkara deer is not a endangered species.

Biologically important compounds that contain both oxygen and nitrogen is protein and nucleic acid. These compounds contain oxygen and nitrogen besides carbon and hydrogen.

Use of large amount of fertilizers and pesticides turns the fields barren after sometime, they affect the useful components of the soil and destroy the soil fertility. Fertilizers and pesticides are not eco-friendly.

The process by which water is lost in form of water vapour from the aerial part of plant is called transpiration. Transpiration is not involved in carbon cycle.

Bandipur sanctuary is situated in Karnataka. Anamalai sanctuary in Tamil Nadu. Sariska sanctuary in Rajasthan but Periyar sanctuary is in Kerela.

Atmosphere plays a very important role in maintaining the  temperature of earth. If there were no atmosphere surrounding  the earth, then the temperature of the earth increase during day and decrease during night.

The major cause of ozone layer depletion includes CFCs (Chlorofluro carbons) that are released from fridges and air conditioners. This gas breaks the ozone (O₃) into free oxygen.

Rhizobium leguminosarum bacterium is capable of nitrogen fixation which resides in the root nodules of legumes plants that convert atmospheric nitrogen into nitrate and nitrite.

Biosphere is the place where living organisms are found. Biosphere includes lithosphere, hydrosphere and atmosphere.

Major part of fresh water is located on mountain tops and glaciers in form of ice caps and glacier. Major portion of water found on earth is salty and found in ocean and seas.

Water hyacinth can be exploited to control water pollution but reduce the oxygen in water. Corbett National park is in the state of Gujarat. Forest check flood and soil erosion. Cow dung cakes and woods are common source of energy in villages.

Both power and manure are provided by biogas plants. Anaerobic respiration of animal wastes and other organic material produce methane gas that is used as excellent fuel and outlets from biogas plant is used as manure.

One percent reduction of ozone in ozonosphere allows 2% higher energy ultraviolet radiations to reach earth. UV radiations cause skin disease to human beings. Endoskeleton and exoskeleton of animals are formed by calcium and magnesium salts.

Rise is temperature of water due to addition of hot water into it is known as thermal pollution. Thermal pollution causes death of aquatic organisms.

Ozone depleting substances (ODS) are those substances that deplete the ozone layer. These substances includes chlorofluorocarbons other gases.