Our Environment – CBSE NCERT Study Resources

The greenhouse effect is the trapping of solar radiation by gases like CO₂ and methane, warming Earth. Our textbook shows it maintains Earth's temperature.

Sunlight enters, but heat is trapped by greenhouse gases. Excess gases from burning fossil fuels intensify this, causing global warming.

• NCERT example: Melting glaciers due to rising temperatures.
• Solution: Use renewable energy like solar panels.

Biodegradable wastes (e.g., paper) decompose naturally, while non-biodegradable wastes (e.g., plastic) persist.

Decomposers break down biodegradable waste, enriching soil. Non-biodegradable waste pollutes soil/water, harming organisms.

• NCERT example: Plastic choking marine life.
• Solution: Segregate waste and recycle.

Ozone depletion is the thinning of the ozone layer due to CFCs, increasing UV radiation.

CFCs from ACs/aerosols react with ozone, breaking it down. Our textbook shows a hole over Antarctica.

• NCERT example: Rising skin cancer cases.
• Solution: Ban CFCs and use eco-friendly products.

Energy flows unidirectionally from producers to top consumers, losing 90% at each trophic level.

Grass → Grasshopper → Frog → Snake. Only 10% energy transfers, rest is lost as heat.

• NCERT example: Fewer top carnivores due to energy loss.
• Solution: Protect producer levels to stabilize chains.

Biomagnification is toxin accumulation at higher trophic levels, e.g., DDT in food chains.

DDT in water → plankton → fish → birds. Birds face eggshell thinning, as per NCERT.

• NCERT example: Eagle population decline.
• Solution: Ban harmful pesticides like DDT.

Sustainable development meets present needs without compromising future resources.

NCERT shows rooftop rainwater harvesting in Rajasthan, recharging groundwater.

• Method 1: Use solar energy.
• Method 2: Recycle paper to save trees.

Decomposers play a crucial role in maintaining the balance of an ecosystem by breaking down dead organic matter and recycling nutrients back into the environment. They act as nature's recyclers, ensuring that essential elements like carbon, nitrogen, and phosphorus are returned to the soil, making them available for plants and other organisms.

Examples of decomposers include bacteria, fungi, and earthworms. For instance, fungi break down dead leaves and wood, while bacteria decompose dead animals and waste materials. Earthworms help by fragmenting organic matter, speeding up the decomposition process.

Without decomposers, dead organisms and waste would accumulate, leading to nutrient depletion and disrupting the food chain. Their activity also helps in the formation of humus, which improves soil fertility and supports plant growth. Thus, decomposers are vital for sustaining life and maintaining ecological balance.

Human activities like industrialization, deforestation, and improper waste disposal have severely impacted the environment, leading to air and water pollution.

Air pollution is caused by emissions from vehicles and factories, releasing harmful gases like carbon monoxide and sulfur dioxide. This leads to respiratory diseases and acid rain.

Water pollution occurs due to dumping of industrial waste and sewage into rivers, contaminating drinking water and harming aquatic life.

Solutions:

• Use of renewable energy (solar, wind) to reduce emissions.
• Proper waste management and recycling.
• Afforestation to absorb pollutants.

The ozone layer is a protective shield in the stratosphere that absorbs harmful ultraviolet (UV) radiation from the sun, preventing it from reaching the Earth's surface.

It is being depleted due to the release of chlorofluorocarbons (CFCs) from refrigerants, aerosols, and industrial processes. These chemicals break down ozone molecules, creating ozone holes.

Measures to protect the ozone layer:

• Banning CFCs and switching to ozone-friendly alternatives.
• Promoting public awareness about the harmful effects of UV radiation.
• Supporting international agreements like the Montreal Protocol to reduce ozone-depleting substances.

Decomposers play a crucial role in maintaining the balance of the ecosystem by breaking down dead organic matter and recycling nutrients back into the environment. They are nature's recyclers and ensure that the biogeochemical cycles continue uninterrupted.

Key roles of decomposers:

• They break down dead plants, animals, and waste materials into simpler substances like carbon, nitrogen, and minerals, which are reused by plants.
• They prevent the accumulation of dead matter, which could otherwise lead to pollution and disease.
• They help in soil enrichment by releasing nutrients that improve soil fertility.

Examples:

• Bacteria and fungi decompose fallen leaves and dead animals, converting them into humus.
• Earthworms break down organic matter in the soil, enhancing its quality.

Without decomposers, nutrients would remain locked in dead organisms, disrupting the food chain and making the ecosystem unsustainable. Thus, they are essential for the energy flow and nutrient cycling in nature.

Decomposers play a crucial role in the environment by breaking down dead organic matter into simpler substances. They include organisms like bacteria and fungi, which feed on dead plants and animals, recycling nutrients back into the soil.

Example: When a leaf falls from a tree, decomposers like fungi break it down into nutrients like nitrogen and carbon, which are then absorbed by plants for growth.

Role in maintaining balance:

• They recycle nutrients, ensuring continuous availability for producers (plants).
• They prevent the accumulation of dead matter, keeping the ecosystem clean.
• They help in the biogeochemical cycles (e.g., carbon and nitrogen cycles) by releasing essential elements back into the environment.

Without decomposers, dead matter would pile up, and nutrients would not be recycled, disrupting the food chain and ecosystem balance.

Decomposers play a crucial role in maintaining the balance of the ecosystem by breaking down dead organic matter and recycling nutrients back into the environment. They are nature's recyclers and ensure that nutrients are not locked up in dead organisms but are made available for reuse by plants and other producers.

Key roles of decomposers:

• They break down dead plants, animals, and waste materials into simpler substances like carbon dioxide, water, and minerals.
• They help in nutrient cycling by returning essential elements like nitrogen, phosphorus, and carbon to the soil, which are then absorbed by plants.
• They prevent the accumulation of dead matter, which could otherwise lead to pollution and disease.

Examples:

• Bacteria and fungi decompose fallen leaves, dead animals, and other organic waste.
• Earthworms break down organic matter in the soil, improving soil fertility.

Without decomposers, ecosystems would collapse as nutrients would remain trapped in dead organisms, and the food chain would be disrupted. Thus, they are vital for sustaining life on Earth.

Decomposers play a crucial role in maintaining the balance of the ecosystem by breaking down dead organic matter into simpler substances. They include organisms like bacteria, fungi, and certain invertebrates such as earthworms. Here’s how they function:

• Breakdown of Dead Matter: Decomposers feed on dead plants, animals, and waste materials, converting them into simpler inorganic compounds like carbon dioxide, water, and nutrients.
• Nutrient Recycling: By decomposing organic matter, they release essential nutrients like nitrogen, phosphorus, and potassium back into the soil, making them available for plants to reuse.
• Energy Flow: They complete the food chain by ensuring that energy trapped in dead organisms is returned to the environment.

Examples: Fungi like Mucor and bacteria like Pseudomonas decompose dead leaves and animal remains. Earthworms break down organic matter in the soil, enriching it.

Contribution to Nutrient Cycle: Decomposers are vital for the biogeochemical cycles (e.g., carbon cycle, nitrogen cycle). They convert complex organic compounds into simpler forms, ensuring continuous nutrient availability for producers (plants), thus sustaining life on Earth.

Decomposers play a crucial role in the environment by breaking down dead organic matter into simpler substances. They are nature's recyclers and help in maintaining the balance of ecosystems. Decomposers like bacteria and fungi secrete enzymes that decompose dead plants, animals, and other waste materials.

Here’s how they contribute:

• Nutrient Recycling: They convert complex organic compounds into simpler inorganic forms like carbon, nitrogen, and phosphorus, which are reused by plants.
• Waste Management: They clean the environment by decomposing dead bodies and waste, preventing accumulation.
• Soil Enrichment: The decomposed matter forms humus, improving soil fertility.

Examples: Fungi like Mucor and bacteria like Bacillus decompose dead leaves and animal remains. Earthworms also aid in decomposition by breaking down organic matter.

Without decomposers, dead matter would pile up, and essential nutrients would remain locked, disrupting the food chain and ecosystem balance. Thus, they ensure sustainability in nature.

Decomposers play a crucial role in the environment by breaking down dead organic matter into simpler substances. They are primarily microorganisms like bacteria and fungi, which feed on dead plants, animals, and waste materials. For example, fungi decompose fallen leaves in a forest, while bacteria break down dead animals.

Their role in maintaining the ecosystem balance includes:

• Nutrient Recycling: Decomposers convert complex organic compounds into simpler inorganic forms like carbon, nitrogen, and phosphorus, which are reused by plants.
• Waste Management: They clean the environment by decomposing waste, preventing accumulation.
• Soil Enrichment: The decomposed material enriches the soil with nutrients, improving fertility.

Without decomposers, dead matter would pile up, and essential nutrients would remain locked, disrupting the food chain and ecosystem stability.

Decomposers play a crucial role in maintaining the balance of an ecosystem by breaking down dead organic matter and recycling nutrients back into the environment. They include organisms like bacteria and fungi, which convert complex dead materials into simpler substances.

Here’s how they contribute:

• Nutrient Recycling: Decomposers break down dead plants and animals, releasing nutrients like carbon, nitrogen, and phosphorus into the soil, which are reused by plants.
• Waste Management: They help in decomposing waste materials, preventing accumulation and pollution.
• Energy Flow: By decomposing dead matter, they ensure energy flows efficiently through the food chain.

Example: Fallen leaves in a forest are decomposed by fungi, enriching the soil for new plant growth. Similarly, bacteria decompose dead animals, returning nutrients to the ecosystem.

Without decomposers, dead matter would pile up, nutrients would be locked away, and the ecosystem would collapse due to imbalance.