Our environment class 10

Introduction:

• Everything around us that surrounds us is environment. It includes both living (biotic) and non-living (abiotic) components.
• Interaction between these biotic and abiotic Components form an ecosystem.
• In an ecosystem living Components depend upon each other for their food which gives rise to food chains and food webs in nature.
• In environment human activities lead to environmental problems such as depletion of ozone layer and production of huge amount of garbage.

Ecosystem:-

• All the interacting organisms in an area together with non-living constituents of the environment forms an ecosystem.E.g. Forests, ponds.
• Types of ecosystem:- Two types
• 1.Natural ecosystem:- The ecosystems which exists in nature on its own.
• Ex:- Forest, lake, ocean.
• 2.Artificial ecosystem:- Man-made ecosystem are called artificial ecosystem.
• Ex:- Crop field, garden, aquarium etc.

Components of ecosystem:- Two

• Abiotic (Air, water, soil) and  
• Biotic (planst and animals)

1.Biotic Component:- 

• All living Components forms biotic Component.
• Ex:- Plants, Animals, fungi etc.

2.Abiotic Component:-

• All non-living Components form an ecosystem.
• Ex:- air, water, land, light etc.

On the basis of nutrition biotic Components are further divided into:-

• Producers
• Consumers

Producers:-

• All green plants and blue green algae can produce their own food using abiotic Components (By photosynthesis)

Consumers:-

• Includes all animals which depends on producers directly or indirectly for their food.

Division of Consumers:-

• 1.Herbivores:- Feed on plants.
• Example:- Goat, deer.
• 2.Carnivores:- Feed on animal's Flesh.
• Example:- Tiger, Crocodile.
• 3. Omnivores:- Eats both plants and animals.
• Example:- Humans, Dog etc.
• 4.Parasites:- Organisms which live either in or on the body of host is called parasite. It is of two types:- ecto-parasite(e.g.lice, cascuta) and endo-parasite(e.g.Liver fluke).

Decomposers:-

• Organism which break down complex food substances into simpler ones.
• Or
• Organisation which feed on dead bodies of plants and animals. 
• Or
• Micro-organism which convert the dead plants and animals to humus.
• E.g. bacteria, fungi.
• Live in soil

Decomposition:- Process in which complex organic matter are broken down into simpler forms.

Rate of decomposition:- Several factors determine rate of decomposition.

• 1.Soil quality:- 
• ✓Abundance of micro-organism,
• ✓moisture content,
• ✓Temperature,
• ✓High aeration,
• ✓pH,
• 2.Compostion of organic matter:-
• 3.Climate.

Importance of decomposition:-

• Convert dead plant and Animals remains into humus.
• Improve soil fertility
• Nutrients are releasing back to soil.

Humus:- 

• Decomposer when eat upon dead plant and animal tissues, they convert them into a dark colour of substance called humus.
• Presence of humus ensures that the nutrients of the dead plants and animals are released into soil

Food chain:-

• Series of living organisms feeding on one another.
• 3 step food chain:-
•  grass -> deer -> lion
• 4 step food chain:-
• Plant -> goat -> fox -> lion
• 5 step food chain:-
• Grass -> insects -> frog -> snake -> eagle

Trophic level:- Each level of a food chain is called trophic level.

Food web:- Network of food chains is called food web. In nature food web exist.

Flow of energy between trophic level:-

• Flow of energy in a food chain is unidirectional.
• Green plants capture 1% of sunlight ad convert it into food energy.

10%Law:-

• Only 10% of energy is transferred to next trophic level. The remaining 90% energy is used in life processes by present trophic level.
• Due to gradual decrease in. Energy food chain contains 3-4 trophic levels.

Decrease in energy:-

1000KJ --> 100KJ --> 10KJ -->1KJ.

Biological magnification:-

• The concentration of harmful chemicals increases with every next trophic level in a food chain. This is caly biological magnification.
• Maximum concentratration of each chemical get accumulated in human bodies as  human occupy the top level in any food chain.

Food web:-

• In nature large numbers of chains are interconnected forming a food web.

Environmental problems:-

• Change in the environment affect us and our activities change the environment around us.
• Human activities leads to pollution, deforestation etc.

Ozone layer:-

• Protective blanket around the earth which absorbs most of harmful UV rays of sunlight, this protecting living beings from many health hazards such as skin cancer, cataract, destruction of plants etc.
• O3 (ozone) layer is present at higher levels of atmosphere.
• Sadly poison at ground level.

Formation ozone molecule:-

• 1.high energy of UV radiation breakdown the O2 molecules into free oxygen atom.
• O2 ( in presence of)-->O + O
• 2.These oxygen atoms combine with oxygen molecule O2 to form ozone molecule.

Depletion of ozone layer:- 

• The decrease in thickness of ozone layer over Antarctica was observed in 1985 and was termed as ozone hole.
• The decrease was linked to excessive use of synthetic chemicals like CFCs which is used in Refrigerators , ACs, fire extinguishers.
• UNEP [United Nations Environment Programme] succeeded in forging an agreement to stop CFC production at 1986 level by all counts.

Garbage Disposal:- 

• Improvements in lifestyle have resulted in accumulation of large amount of waste material

Types of material in Garbage:- 

1.) Biodegradable:-

• Substances which can be decomposed by the action of micro-organisms are called biodegradable waste.
• Ex:- Fruits, Vegetables peels, paper etc.

2.) Non-biodegradable:- 

• Substances which cannot be decomposed by the action of micro-organisms are called non-biodegradable waste.
• Example:- Plastic, metals, pesticides etc.
• Micro-organisms release enzyme which decompose the material but these enzymes are specific in their action that's why enzymes cannot decompose all the materials.

Methods of waste disposal:-

1.Biogas Plant:-

• Biodegradable waste can be used in biogas plant to produce biogas and manure.

2.Sewage treatment plant:-

• The drain waste can be cleaned in sewage treatment plant before adding it to rivers 

3.Land fillings:- 

• The wastes are buried in low lying areas and compacted by rolling with bulldozers

4.Composting:-

• Organic wastes are filled in a compost pit and converted with a layer of soil, after about three months garbage changes to manure.

5.Recycling:-

•  Non-biodegradable wastes are recycled to make new items.

6.Reuse:- 

• It is a conventional technique to use an item again.
• Example:- Newspaper for making envelops 

Thankyou...