Class 10 Science - BIHAR
Our Environment
The chapter 'Our Environment' in Class 10 Science explores how human activities and natural processes interact within our surroundings. It covers critical topics such as ecosystems, biotic and abiotic components, food chains, food webs, and the flow of energy through trophic levels. Students will also learn about biological magnification (biomagnification), ozone layer depletion, and effective waste management strategies like biodegradable and non-biodegradable waste. This chapter holds significant weight in the Bihar (BSEB) board exams, frequently appearing in both objective and subjective sections, making it a high-scoring area for students who understand the conceptual linkages.
Start Learning FreeKey Concepts
Ecosystem
A self-sustaining community of living organisms (biotic) interacting with each other and their physical environment (abiotic) such as soil, water, and air.
Food Chain and Food Web
A food chain shows a linear sequence of who eats whom in an ecosystem, while a food web is a complex, interconnected network of multiple food chains.
Ten Percent Law
Only 10% of the energy is transferred from one trophic level to the next in a food chain, while the remaining 90% is lost to the environment as heat.
Biological Magnification
The progressive accumulation of harmful toxic chemicals, such as pesticides, in living organisms at each successive trophic level.
Ozone Layer Depletion
The thinning of the protective ozone shield in the stratosphere mainly caused by the release of Chlorofluorocarbons (CFCs), allowing harmful UV rays to reach Earth.
Waste Management
The proper handling and disposal of waste materials, categorized into biodegradable substances broken down by microbes and non-biodegradable substances that persist.
Important Formulas
Board Exam Info
In the Bihar (BSEB) Class 10 Science board exam, 'Our Environment' typically carries around 3 to 5 marks. Questions generally include multiple-choice questions (MCQs), short-answer questions defining ecological terms like food web or ozone depletion, and reasoning questions based on the 10% energy flow law.
Frequently Asked Questions
What is the role of decomposers in an ecosystem?
Decomposers like bacteria and fungi break down complex organic remains and waste products into simple inorganic substances, recycling nutrients back into the soil for plants.
Why is the flow of energy in an ecosystem always unidirectional?
Energy flows in only one direction because the energy captured by autotrophs does not revert back to the sun, and energy lost as heat at each trophic level cannot be reused by organisms.
How do CFCs deplete the ozone layer?
Chlorofluorocarbons (CFCs) rise to the stratosphere where ultraviolet rays break them down to release active chlorine atoms, which continuously break down ozone molecules into oxygen.
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