Here cbse class 10 science our environment notes is very use full for for all students who are studing in class 10 science cbse and ncert
CBSE Class 10 Science Our Environment Notes
1. Introduction
2. Ecosystem and It’s Components
i) Ecosystem
ii) Types of Ecosystem
iii) Components of Ecosystem
iv) Food Chains and Webs
CBSE Class 10 Science Our Environment Notes
3. How do Our Activities Affect the Environment
CBSE Class 10 Science Our Environment Notes
i) Ozone Layer and How it is Getting Depleted
ii) Managing the Garbage we Produce
CBSE Class 10 Science Our Environment Notes
1. Introduction: CBSE Class 10 Science Our Environment Notes
1. Everything that surrounds us is environment.
2. It includes both living (biotic) and non-living (abiotic) components.
CBSE Class 10 Science Our Environment Notes
2. Ecosystem and its Components:
CBSE Class 10 Science Our Environment Notes
i) Ecosystem:
All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem.
Example: forest, pond etc.
ii) Types of ecosystems: These are two types
a) Natural ecosystem:
The ecosystem which exist in nature on its own.
Example: forest, lake, ocean.. etc.
b) Artificial ecosystem:
Man-made ecosystems are called artificial ecosystem.
Example: crop field, aquarium, garden.
CBSE Class 10 Science Our Environment Notes
iii) Components of ecosystems: These are two types
a) Biotic Components:
All the living organisms present in this ecosystem
Example: Plants, animals, microorganisms.. etc.
It includes mainly three categories of organisms
(i) Producers:
Organisms that produce their own food through photosynthesis.
Example: plants
(ii) Consumers:
Include all animals which depend on producers directly or indirectly for their food.
Example: Lion, insects
Consumers are classified into the following groups..
(a) Herbivores: Plant eaters. Ex: goat, deer.
(b) Carnivores: Flesh eaters Ex: Lio, tiger…. etc.
(c) Omnivores: Eat both plants and animals. Ex: Human
(d) Parasites: Live on the body of host and take food from it. Ex: Lice, cascuta.. etc.
(iii) Decomposer’s:
Microorganisms that break down dead organic matter (dead plants and animals).
Example: Bacteria, fungi
(b) Abiotic Components:
Non-living factors in an ecosystem.
Example: Water, Air, Soil, Temperature, Light
iv). Food chains and Webs:
(a) Food Chain: A linear sequence of organisms consuming other organisms for energy.
Example: Grass à Deer àTiger
à On the basis of habitat, food chains are two types
(i) Terrestrial food chain: It is the food chain present on land.
Grass à Deer à Tiger
CBSE Class 10 Science Our Environment Notes
https://studentfavour.com/life-processes-class-10-cbse-ncert-solutions/
(ii) Aquatic food chain:
It is the food chain present in different water bodies.
iv). Food chains and Webs:
(b) Food Web:
The interconnection of different food chains in an ecosystem are called food web.
Example:
Forest ecosystem with multiple food chains.
CBSE Class 10 Science Our Environment Notes
Trophic levels:
The transfer of food or energy takes place through various steps or levels in the food chain known as Trophic levels.
Types of Trophic levels:
Tertiary consumers T4
Secondary consumers T3
Primary consumers. T2
Producers T1
Energy Flow:
Energy flow refers to the transfer of energy from one tropic level to another.
Energy Flow Pattern: Top Carnivores
Producers àPrimary Consumersà Carnivores
Secondary Consumers àTertiary Herbivores
Consumers Producers
Sunlight
Energy Flow:
1. Flow of energy in a food chain is unidirectional.
2. Green plants capture 1% of sunlight and convert it into food energy.
3.10 percent law: Only 10% of energy is transferred to the next trophic level. The remaining 90% energy is used in life processes (digestion, growth, reproduction etc.) by present trophic level.
4. Due to this gradual decrease in energy, food chains contain 3-4 trophic levels.
Question:
What percentage of energy is transferred from one trophic level to the next level?
a) 5%
b) 10%
c) 15%
d) 90%
Biological magnification or Bio magnification:
The increase in concentration of harmful substances (like pesticides, heavy metals, or pollutants) in living organisms as they move up the food chain.
Example:
1. Pesticides are sprayed on crops.
2. Insects absorb pesticides.
3. Frogs eat contaminated insects.
4. Birds eat contaminated frogs.
5. Humans eat contaminated birds (or fish).
6. The concentration of pollutants increases at each level of the food chain.
3. Ozone Layer and How it is Getting Depleted:
i) Ozone Layer and How it is Getting Depleted:
Ozone Layer:
1. Ozone layer is a protective blanket around the earth which absorbs most of the harmful UV (ultraviolet) radiations of the sunlight, thus protecting living beings from many health hazards such as skin cancer, cataract, destruction of plants etc.
2. Ozone (03) layer is present at higher levels of atmosphere (i.e. stratosphere). It is a deadly poison at ground level.
3. How do Our Activities Affect the Environment:
Formation of Ozone molecule:
1. The high energy UV radiations break down the O₂ molecules into free oxygen (O) atoms.
O2 (UV) → O + O (atoms)
2. These oxygen atoms then combine with oxygen (02) molecule to form the ozone molecule.
O2 + O – O3 (Ozone)
3. How do Our Activities Affect the Environment:
Deflection of Ozone layer:
1. The amount of ozone in the atmosphere began to drop sharply in the 1980s.
2. This decrease has been linked to synthetic chemicals like chlorofluorocarbons (CFCs) which are used as refrigerants and in fire extinguishers.
3. In 1987, the United Nations Environment Programme(UNEP) succeeded in forging an agreement to freeze CFC production at1986 levels.
4. It is now mandatory for all the manufacturing companies to make CFC-free refrigerators throughout the world.
ii) Managing the Garbage we Produce:
a) Garbage disposal:
Improvements in lifestyle have resulted in accumulation of large amounts of waste materials.
Types of materials in Garbage
(i) Biodegradable:
Substances which can be decomposed by the action of micro-organisms are called biodegradable wastes.
Examples: fruit and vegetable peels, cotton, jute, dung, paper, etc.
(ii)Non-Biodegradable:
Substances which cannot be decomposed by the action of micro-organisms are called non-biodegradable wastes.
Examples: Plastic, polyethene’s, metals, synthetic fibers, radioactive wastes, pesticides etc.
“Micro-organisms release enzymes which decompose the materials but these enzymes are specific in their action that’s why enzymes cannot decompose all the materials.”
(b) Methods of waste disposal:
i) Biogas plant:
Biodegradable waste can be used in biogas plant to produce biogas and manure
ii) Sewage treatment plant:
The drain water can be cleaned in sewage treatment plant before adding it to rivers.
iii) Land fillings:
The wastes are buried in low lying areas and are compacted by rolling with bulldozers.
iv) Composting:
Organic wastes are filled in a compost pit and covered with a layer of soil, after about three months garbage changes to manure.
v) Recycling:
Non-biodegradable wastes are recycled to make new items.
vi) Reuse:
is a conventional technique to use an item again.
Example: newspaper for making envelops.
Thank You
CBSE Class 10 Science Our Environment Notes