Multiple Choice Questions (MCQs)
(i) What does the term 'environment' include?
(a) Only living things
(b) Only non-living things
(c) Both living and non-living things
(d) None of the above
Ans: (c)
The environment encompasses all elements that surround us, which includes biotic components (living things such as plants and animals) and abiotic components (non-living things such as air, water, and soil). Together, these components form a complex and interrelated system.
(ii)Which type of waste can be broken down by natural processes?
(a) Non-biodegradable
(b) Biodegradable
(c) Industrial waste
(d) Inorganic waste
Ansr: (b) Biodegradable
Biodegradable waste consists of organic material that can easily decompose through natural processes, aided by microorganisms such as bacteria and fungi. Examples include food scraps, garden waste, and paper.
(iii)What is the primary cause of air pollution?
(a) Deforestation
(b) Soil erosion
(c) Industries and vehicles
(d) Overpopulation
Ans: (c)
The main contributors to air pollution are industries and vehicles, which emit large amounts of pollutants such as carbon monoxide, nitrogen oxides, particulate matter, and other harmful substances into the atmosphere, significantly degrading air quality.
(iv) Which gas is a major component of biogas?
(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
(d) Methane
Ans: (d)
Biogas is primarily composed of methane, a potent greenhouse gas that is produced through the anaerobic digestion of organic materials by microorganisms. Methane in biogas is used as a fuel source, as it is highly combustible.
(v) What effect does global warming have on ice caps?
(a) They expand
(b) They melt
(c) They become thicker
(d) They change colour
Ans: (b)
Global warming leads to an increase in Earth's average surface temperature due to the enhanced greenhouse effect caused by increased levels of greenhouse gases in the atmosphere. This rise in temperature results in the melting of polar ice caps and glaciers, contributing to rising sea levels and altering habitats.
Fill in the Blanks
(i) Waste that does not rot and cannot be broken down by decomposers is called ________ waste.
Ans: Non-biodegradable
(ii) The lowest layer of Earth's atmosphere is the ________.
Ans: Troposphere
(iii)______ is a technique that uses red earthworms to break down organic material into vermicompost.
Ans: Vermicomposting
(iv)______ pollution is caused by the loud noise of machines and vehicles.
Ans: Noise
(v) The process of managing waste by creating new products from old items is called ________.
Ans: Recycling
True or False
(i) The environment only includes living things.
Ans: False
The environment comprises both biotic (living) and abiotic (non-living) components. Living things like plants and animals, as well as non-living elements such as water, air, and soil, are essential parts of the environment.
(ii) Biodegradable waste is harmful to the environment.
Ans: False
Biodegradable waste is not inherently harmful to the environment; it consists of organic materials that naturally decompose. When managed properly, it can be converted into useful compost or biogas, thus recycling nutrients back into the ecosystem.
Ans: True
Recycling involves processing used materials into new products to prevent waste of potentially useful materials. This reduces the consumption of fresh raw materials, decreases energy usage, and lowers greenhouse gas emissions, helping to reduce environmental pollution.
(iv) Greenhouse gases do not include oxygen.
Ans: True
Greenhouse gases, such as carbon dioxide, methane, and water vapor, trap heat in the Earth's atmosphere. Oxygen, while vital for life, is not a greenhouse gas as it does not contribute to the greenhouse effect.
(v) Global warming is solely caused by natural processes.
Ans: False
Global warming is primarily driven by human activities, particularly the emission of greenhouse gases from burning fossil fuels, deforestation, and industrial processes. Natural processes also contribute, but the current trend of rapid warming is largely anthropogenic.
(vi) Landfills are a sustainable method to manage waste.
Ans: False
Landfills involve burying waste in the ground and can lead to environmental problems such as soil and water contamination. They are considered less sustainable compared to other waste management methods like recycling and composting, which aim to reuse and repurpose waste.
(vii) Noise pollution only affects humans.
Ans: False
Noise pollution affects not only humans but also animals, particularly wildlife. It can disrupt the living patterns of animals, interfere with animal communication, reproduction, and navigation, and lead to various health issues in humans such as hearing loss and increased stress levels.
(viii) The increase in atmospheric carbon dioxide levels has no effect on ocean chemistry.
Ans: False
Increased levels of carbon dioxide in the atmosphere lead to greater CO2 absorption by the oceans, causing ocean acidification. This chemical change can have detrimental effects on marine life, particularly organisms that build shells or skeletons of calcium carbonate, such as corals and some shellfish.
Match the Following
Ans:
A - ii
B - i
C - iii
D - iv
E - v
Odd One Out Questions
(i) Sunlight, Water, Plastic, Air
Ans: Plastic
Sunlight, water, and air are all natural elements essential for life and are naturally occurring components of the environment. Plastic, however, is a man-made material and not a natural component of the environment.
(ii) Composting, Recycling, Landfill, Vermicomposting
Ans: Landfill
Composting, recycling, and vermicomposting are all waste management practices that contribute to environmental sustainability by recycling nutrients back into the ecosystem or converting waste into new materials. Landfilling, however, typically involves the burial of waste in the ground, which can lead to environmental degradation and is less sustainable.
(iii) Carbon dioxide, Oxygen, Methane, Nitrogen
Ans: Oxygen
Carbon dioxide, methane, and nitrogen (in the form of nitrous oxide) are greenhouse gases that contribute to the greenhouse effect and global warming. Oxygen, while a critical component of the atmosphere for life, does not contribute to the greenhouse effect.
(iv) Recycling, Reducing, Reusing, Burning
Ans: Burning
Recycling, reducing, and reusing are all sustainable practices aimed at waste management to minimize environmental impact. Burning, however, often leads to air pollution and is not considered a sustainable practice due to its negative impact on air quality and contribution to global warming.
Real Life Application Questions
(i) How can the practice of recycling benefit our community in the long run?
Ans: Recycling helps in reducing the amount of waste sent to landfills, conserves natural resources, saves energy, and reduces pollution, thereby supporting environmental sustainability and keeping our community healthy.
(ii) What simple steps can you take at home to reduce air pollution?
Ans: Use energy-efficient appliances, limit the use of heaters and air conditioners, avoid burning trash, use public transport or carpool when possible, and use paints and cleaning products that are environmentally friendly.
