NCERT Solutions for Class 10 Science Chapter 15
NCERT Solutions for Class 10 Science Chapter 15 Our Environment intext questions given on Page 257 or Page 261 or Page 264 and Exercises questions answers in English & Hindi Medium updated for new session 2020-21.Download NCERT Solutions Offline apps in Hindi and English Medium free for 2020-2021. 10th Science Chapter 15 answers on पेज 289 or पेज 294 or पेज 296 or अभ्यास के प्रश्न उत्तर in हिंदी to study online free or download in PDF form. All the NCERT Solutions are updated according to new CBSE Syllabus 2020-21.
NCERT Solutions for Class 10 Science Chapter 15
|Chapter 15:||Our Environment|
10th Science Chapter 15 Answers in English & Hindi Medium
NCERT Solutions for Class 10 Science Chapter 15 Our Environment in PDF form to free download English and Hindi Medium. Download NCERT Solutions Apps for offline use. Download NCERT Solutions 2020-21 for class x other subjects are also in PDF format. Study online or download, use as per your requirement.
10th Science Chapter 15 Answers in English Medium
10th Science Chapter 15 Answers in Hindi Medium
10th Science Chapter 15 Answers in PDF Form
Mention one negative effect of our affluent life style on the environment.
Excessive use of fossil fuel, even when we have to go nearby we use car, motor cycle, etc. instead going on foot or by cycle. Fossil fuels, on burning produce oxides of carbon, nitrogen and sulphur which cause air pollution.
Why is energy flow in the biosphere unidirectional?
The sun is the only source of energy which plants trap during photosynthesis and store as food. The transfer of energy from one trophic level to the other obeys 10% law, i.e., 90% of energy is lost as heat. The energy in the form of heat goes unutilised because plants cannot use this heat energy in the synthesis of food. Thus, there is always flow of energy from the non-living component (then sun) and is released as heat. So, the energy flow in the biosphere is unidirectional.
What is an Eco-system?
Eco-system is the whole biotic community (living organisms) in a given area plus its abiotic environment (physical factors like temperature, rainfall, wind, soil and minerals) both interacting with each other and maintain a balance in nature. Eco-system can be as large as a forest, or small as a pond or lake. This functional system may be natural as forest or may be artificial (man-made), e.g., a crop field or an aquarium. Thus the Eco-system has biotic and abiotic components.
What is ozone and how it affect any Eco-system?
Ozone(O3) a molecule formed by three atoms of oxygen. It is a deadly poisonous gas. However, at the higher level of atmosphere, it performs an essential function. It shields surface of earth from ultraviolet radiation (UV) of solar radiations. This radiation is highly damaging to organisms, it is known to cause skin cancer, cataract in human beings.
Questions for Practice
What are two components of our environmental?
(i) Biotic components: Plants and animals.
(ii) Abiotic components: Air, water, soil etc.
Distinguish between biodegradable and non-biodegradable substances. List two effects of each of them on our environment.
(i) They can be broken into simplest form by biological processes.
(ii) They do not produce more pollution.
(iii) They remain for less time in environment.
(i) They cannot be broken by biological processes.
(ii) They produce more pollution.
(iii) They remain for a long time in the environment.
Effect of biodegradable substances:
(i) They release harmful gases like methane.
(ii) They release foul smell.
Effect of non-biodegradable substances:
(i) They are very harmful for the various member of the ecosystem.
(ii) They cause more pollution of air, water and soil.
Questions from Board Papers
Explain the phenomenon of “biological magnification”. How does it affect organisms belonging to different trophic levels particularly the tertiary consumers?
When any harmful chemical like DDT, BHC enters in a food chain the concentration of chemical increases as the trophic level is increased (i.e., next higher level). The phenomenon is called biological magnification.
These chemical, get accumulated progressively at each trophic level. It is maximum at the top (highest) trophic level. The tertiary consumers occupy the top trophic level (in most of the food chains) so there is maximum concentration of the harmful chemicals ant they are affected badly.
The flow of energy in food chain is unidirectional. Why?
The flow of energy in a food chain follows 10% law. The energy used or lost in environment as heat, cannot enter at any trophic level in the food chain. Only solar energy can enters in the food chain at producer level and ultimately get lost as heat.
Important Questions on 10th Science Chapter 15
Slow decomposition of biodegradable waste will result in the release of foul smell and harmful gases. When inhaled by human beings, they may cause irritation, nausea, giddiness, etc.
Decomposing waste provides breeding ground for some harmful organisms. Abundance of harmful microorganisms may cause diseases in animals, plants and human beings.
Increase in the number of microorganisms in aquatic medium will- cause oxygen deficiency in waterbodies.
During decomposition it provide a breeding ground for mosquitoes, insects and microbes responsible for diseases like cholera, diarrhoea, etc.
Handling of waste materials may cause skin, respiratory and intestinal infections.
Non-biodegradable substances do not decompose easily so it produces land and water pollution.
Separating biodegradable and non-biodegradable waste before dumping them.
Recycling the non-biodegradable waste material.