Our Environment: Class 10 Science NCERT Chapter 15

Key Features of NCERT Material for Class 10 Biology Chapter 15 – Our Environment

In the previous chapter 14, you learned about Sources of Energy. In this chapter: Our Environment, you will learn about what our environment go through for us.

Quick revision notes

Biodegradable and Non-biodegradable Wastes, Ecosystem, Components of Ecosystem. Nature incorporates our physical environmental factors like air (or air), water bodies, soil (land and all the creatures, for example, plants, creatures, people and small scale life forms like microbes and organisms (called decomposers). The waste materials delivered by the different exercises of man and creatures are toxic somewhat and can be separated into two fundamental gatherings.

  1. Biodegradable Wastes: Substances that are separated by the organic cycles are supposed to be biodegradable. These substances are disintegrated through the activities of growths, microorganisms, and other living beings. Temperature and daylight additionally assume a significant job in the deterioration of biodegradable substances.

For Examples: Food squander, trees leaves, pee and fecal issue, sewage farming buildup, paper, wood, material, bovine excrement and so on.

  1. Non-Biodegradable Wastes: Substances that are not separated by natural measures. These substances might be in strong, fluid or vaporous structure. These substances are latent and just endure in the earth for quite a while or may hurt the different individuals from the biological system.

For Examples: DDT (Di-chloro-di phenyl trichloro ethane-in-pheneyle the cheoro ethane), bug sprays, pesticides, mercury, etc. These non-biodegradable wastes are significant poisons of the earth.

Unsafe impacts of biodegradable and Non-Biodegradable Substance

  1. The waste devastates the characteristic magnificence and our environmental factors become grimy.
  2. Decomposition of these squanders brings about the creation of foul smell, which spreads to the encompassing regions.
  3. These squanders may likewise obstruct the channels making pools of waste, which turns into the rearing destinations of mosquitoes. The last is transporters of sicknesses like jungle fever and dengue.

Difference between Biodegradable and Non-Biodegradable wastes

Biodegradable wastes Non-Biodegradable wastes
1. The wastes that are separated normally by microbial activity. 1. The wastes that are not separated by the microorganisms.
2. Biodegradation structures innocuous and non-toxic items. 2. No such activity is conceivable.
3. They discharge crude materials back to nature. 3. They don’t deliver crude materials.
4. They dirty the earth just when they are delivered in amount past the limit of nature to debase them. 4. Non-biodegradable wastes contaminate the earth even in little amount.
5. Bioconcentration doesn’t happen. 5. Bioconcentration or biomagnifications happens when squanders enter natural pecking orders.
6. Reusing is conceivable both normally or through human methods. 6. Reusing is conceivable just through human methods.

Ecosystem: An Ecosystem is an independent unit of living things (plants, creatures and decomposers), and their non-living condition (soil, air and water). For instance; a woods, a lake, a lake, a green land and so forth.

In a biological system, vitality and matter are constantly traded among living and non-living parts.

An environment can be both regular or man-made. A few instances of characteristic environments are field, timberland, ocean, stream, desert, mountain, lake, lake and so forth.

The desert, meadow and mountains speak to the earthbound biological system (land-based environment).

The lakes, streams, lakes and ocean speak to the sea-going biological system (water-based environment). Man-made counterfeit biological systems are garden, crop fields, park, aquarium, and so forth.

Segments of Ecosystem: There are two parts of an environment :

(i) Biotic segment and (ii) Abiotic segment.

  1. 1. Biotic segment: It incorporates three sorts of living beings :

(a) Producers: All green plants, blue green growth can deliver their food (Sugar and starch) from inorganic substance utilizing light vitality (Photosynthesis). In this way, all green plants are called makers. They are additionally called autotrophs.

Tiny fishes are exact moment or minuscule living beings unreservedly skimming on the outside of water in a lake, lake, stream or sea. Tiny fishes are of two kinds : Phytoplanktons and Zooplanktons.

The tiny oceanic plants unreservedly skimming on the outside of water are called phytoplanktons.

The minute amphibian creatures openly coasting on water are called zooplanktons. The uninhibitedly gliding protozoa are a case of zooplankton.

(b) Consumers: They are creatures which devour different life forms or their items as their food. All creatures have a place with this class. The customers rely on makers for their food straightforwardly or by implication. They get their food by eating different life forms or their items. For instance, man, goat, deer, fish, lion, cow, wild ox, and so forth., are basic purchasers.

The purchasers can be characterized into the accompanying sorts :

  •       Herbivores.
  •       Carnivores.
  •       Parasite.
  •       Omnivores.

(i) Herbivores: These are living beings (creatures) which get their food by eating the makers (or plant) straightforwardly. Herbivores are additionally called first request customers. Some basic instances of herbivores are : deer, bunny, rodent, squirrel, goat, cows, and so on.

(ii) Carnivores: These are life forms (creatures) which devour different creatures. Along these lines, carnivores feed on the tissue of herbivores. These are additionally called essential carnivores or second request shoppers. Some normal models are snake, wild feline, jackal, frog, a few winged creatures, fishes, and so on.

There are creatures which go after essential carnivores. They are called second request shoppers or third request buyers. For instance, owl, peacock, tiger, lion, and so on., are some second request carnivores and might be eaten by third request carnivores. The carnivores which are not gone after further are called top carnivores. For instance, lion is a top meat eater.

(iii) Omnivores: The creatures which feed on the two plants and creatures are called omnivores. People are regular case of omnivores since they eat the two plants (For instance; beats, grams, oilseeds, organic product, and so forth.) and creature items (milk, meat, egg, and so on.).

(c) Decomposers: Fungi and microbes which separate (disintegrate) the dead plants, creatures complex mixes into the less difficult one. The decomposers help in the renewal of regular assets. These are otherwise called microorganism or saprotrophs. These are likewise called reducers.

Significance of Decomposers

  •       Decomposers help in discarding the squanders and dead assemblages of plants and creatures. Thusly, they clean nature and make space professionally of fresher ages of life forms.
  •       The decomposers discharge minerals and other crude materials caught in natural issue. These are gotten by plants. This additionally assists with keeping up the fruitfulness of soil.
  •       The decomposers produce a few acids which are valuable in solubilization of certain minerals.
  •       Decomposers help in reusing the materials in the biosphere so that, the cycle of life may continue forever like a ceaseless chain.


  1. Abiotic Segment: These are non-living parts of a biological system. These incorporate the physical condition.
  •       Edaphic factors like soil surface, geology, water, and air.
  •       Inorganic substances like carbon dioxide, nitrogen, oxygen, water, phosphorus, sodium, potassium, and calcium. These are associated with the cyclic of materials in the environment.
  •       Natural mixes like proteins, sugars, and lipids. These to a great extent structure the living body and connection the abiotic and biotic segments.

Climatic elements: These are daylight temperature, pressure stickiness, dampness, precipitation, and so forth these elements influence the circulation of the life forms.

Elements of an Ecosystem

  •       Environment shows accessible sun based vitality and the productivity of a biological system to trap the equivalent.
  •       It gives data about the accessible fundamental minerals and their reusing periods.
  •       It gives information about the snare of collaborations and between relationship among the different populace just as between the populace and the abiotic condition.
  •       It encourages people to think about preservation of assets, assurance from contamination and information sources required for expanding profitability.
  •       In the biological system, two cycles of vitality stream and biogeochemical cycles (supplements development) continue one next to the other. The vitality stream is unidirectional while the development of supplements is cyclic.

Evolved way of life, Food web, Trophic levels. Stream of vitality 10% law, Depletion of the ozone layer, Biological amplification, Method of garbage removal.

Food Chain: The grouping of living life forms in a network in which one creature devours another living being to move food vitality, is known as an evolved way of life.

A food chain  is unidirection where move of vitality happens just a single way.

Or on the other hand

Food Chain is consecutive cycle which speaks to “who eats whom”.

Or then again

Food Chain refers to a game plan of various biotic gatherings in a grouping of vitality move. These biotic gatherings are maker herbivores, carnivores.

For instance, T1(Grass) → T2(Deer) → T3(Lion)

Instances of Food Chains: Simple food chain.

Grass(Producer) → Deer(Herbivore) → Lion(Carnivore)

In this food chain grass speak to the makers (first tropic level). Grass orchestrate their own food by the cycle of photosynthesis. Grass is eaten up by deer, which speaks to the herbivores or the essential buyers. Deer thusly is devoured by lion, the carnivores or the optional shoppers.

A food chain in grasslands which has four stages is :

Grass(Producers) → Insect(Herbivores) → Frog(Carnivores) → Eagle(Secondary Carnivore)

Noteworthiness of Food Chains

  •       The investigation of food chains helps in understanding food connections and collaborations among the different creatures in an environment. The food chains, move vitality and materials between different living parts of a biological system.
  •       The food chains move vitality and materials between different living segments in a biological system or biosphere.
  •       The food chains offer dynamicity to a biological system or biosphere.
  •       The development of poisonous substances like pesticides, weedicides, and so forth, through food chains, can demonstrate unsafe.

Food Web: The between associated food chains working in a biological system which set up a system of connection between different species, are known as a food web.

In a food web, one creature may possess a situation in more than one food chain. A creature can get its food from various sources and thusly, might be eaten up.

Trophic Levels: The different strides in the natural way of life at which the exchange of food (or vitality) happens is called trophic levels.

There is a slow lessening in the measure of vitality move starting with one trophic level then onto the next trophic level in an evolved way of life.

So just 10% of energy is moved to next trophic level while 90% of vitality is utilized by present trophic level in its life measures.

The different trophic levels are given underneath :

  •       The plant or the makers comprise the primary trophic level.
  •       The herbivores or essential purchasers structure the second trophic level.
  •       Carnivores or optional purchasers make up the third trophic level.
  •       Enormous carnivores or the tertiary shoppers which feed upon the little carnivores establish the fourth trophic level.
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