Our environment Class 10 notes

 Our environment

The physical and biological world where we live is called our environment full stop the environment includes our physical surroundings like a or water bodies soil and all the organisms such as plants animal human beings and microorganisms like bacteria and fungi. All this constituents of the environment are depend on one another act with one another and maintain a balance in the environment in a natural way.

Biodegradable and non biodegradable wastes

All the best materials produced by the previous activities of man and animals are poisonous to some extent and can be divided into two main groups:

1. Biodegradable wastes

2. Non biodegradable waste

Those waste material switch can be broken down to non poisonous substances in nature in due course of time by the action of microorganisms like certain bacteria are called biodegradable waste. Biodegradable waste Decay naturally and becomes harmless after sometime. Cattle dunk and composed are common examples of biodegradable waste. The waste materials which cannot be broken down into non poisonous or harmless substances in nature are called non biodegradable waste. The example of non biodegradable waste are: D.D.T, plastics polythene bags ballpoint pen synthetic fibers glass objects etc. 

Ecosystem

The various communities of living organisms interact among themselves as well as with their physical environment like soil air and water full stop the living organisms interact with one another through their food chain in which one organism consumes another organism. The living organisms like plant interact with soil to get essential nutrients like nitrogen Phosphorus etc with air to get carbon dioxide and also with water bodies for caring out the process of photosynthesis the various communities of living organisms like plants and animals along with soil air and water of that region from a cell sustaining or functional unit of the living world. Made up of living and nonliving components which is capable of independent existence is called an ecosystem. Content unit of living things and their non living and environment. Needs only the input of sunlight energy for its functioning full stop the examples of ecosystem grassland forest desert amount Lake river and sea.

Producers, Consumers and Decomposers

According to the manner in which day obtain their food from the environment all the organisms can be divided into 3 groups: producers consumers and decomposers.

1. Producers

Dost organisms which produce food are called producers. Producers are the organisms which can prepare their own food from simple inorganic substances like carbon dioxide and water by using sunlight energy in the presence of chlorophyll. The example of producers are green plants and certain blue green algae full stop the green plants synthesize their food during photosynthesis by taking raw materials from the earth and energy from the Sun. Thus, the green plants are called producer in the living world.

2. Consumers

Those organisms which consume prepared food by producers are called consumers full stop the consumers depend on producers directly or indirectly for their food. The consumers get their food by eating other organisms or their products full stop in simple words consumer are the organisms that eat other organisms. All the animals are consumers full stop even the microscopic animal life of the water called protozoa are consumer organisms full stop the examples of common consumers organisms are man goat,deer, fish,lion ,cow and buffalo etc. The cow and buffalo eat green grass and other green fodder because green grass and other green plants are producers of food. The biomass of grass and plants supplies food and energy to this animals like cow and buffalo full stop it should be noted that the consumer organisms like animal cannot prepare food from simple inorganic substances through photosynthesis. If an animal AIDS grass or other green plants or their products itself we say that it gets the food from producer directly. If an animal its the meet of another animal then we say that it gets the food from producer in directly. Consumers can be for the divided into 3 groups carnivores and omnivores.

3. Decomposers

The non green microorganisms like some bacteria and fungi which are in capable of producing their food, live on the dead and the king plants and animal bodies an are consumers of a special type called decomposers full stop the microorganisms which breakdown the complex organic compounds present indeed organisms like their plants and animals and their products like urine fishes etc into simpler substances are called decomposers. The examples of decomposers are certain bacteria and fungi full stop the bacteria which act as decomposers are called putrefying bacteria. The bacteria and fungi act as decomposers by the secretion of their body surfaces which decompose the organic matter present in dead plants and animal into simpler substances and liberate ammonia carbon dioxide etc. They observe sum of the simpler substances for their own maintenance and release the remaining into the soil, water and air to be used by the producer again in this way decomposers help in the recycling of materials in ecosystem. The decomposers are also known as micro consumers or saprotrophs.

Food chain

Anything which we eat to Live is called food. Food contains energy. The food can we transfer from one organism to the other through food chains. The starting point of a food chain is a category of organisms called producers full stop producers are in fact we can say that all the food chains begin with a green plant which is the original source of all food.

Suppose there is a field having a lot of green plants. Now plans can be eaten up by a rat. The right in turn can be eaten up by a cat. And finally the cat can be eaten up by your dog full stop so we find that there is a sequence or order in which one organism it's up the other organism to fill its belly. The sequence of living organisms in a community in which one organism consume another organism to transfer food energy is called a food chain.

   Grass----------- Deer-------------- lion

   This food can tells us that grass is the starting point of this food chain. The grass is eaten up by dear and the dear is then eaten up by a lion. In this food chain grass is the producer organism which uses sunlight energy to prepare food like carbohydrate by the process of photosynthesis. This grass is than consume by a herbivore dear is consumed by a carnivore called lioon. 

   Food web

 A large number of food chains exist in a community of living organism in an ecosystem such as grassland a forerst or a crop-field. Many of this food chains are interconnected by a species which occur in more than one food chain full stop the interconnected food chains operating in an ecosystem which established the network of relationship between various species is called a food web full stop in simple words the network of a large number of food chains existing in an ecosystem is called a food web full stop the food web has many enter crosses and linkage among the various species. This means that the various food chain in an ecosystem do not operate in isolation.

Trophic level

Food chain represent the flow of food in a given set of organisms or living beings. The various steps in a food chain at which the transfer of food takes place are called trophic levels. Ine most simple terms traffic level means feeding label of the organism. Are called primary consumers small carnivores are called secondary consumers where as top carnivores or large carnivores are called territory consumer. So we can draw another diagram to represent various traffic level by using the terms producers primary consumer secondary consumers and territory consumers. The traffic level in a food chain can also be represented by pyramid of numbers.

Effect of man's activities on the ecosystem

Man or for that matter any other living organism must interact properly with the rest of the ecosystem because he is an integral part of the ecosystem full stop some of the men's activities like hunting a various animals distrupt the food chains in which this animals normally take part. This disruuption of one food chain effects the numerals other food chains operating in the food web. The certaining of food chains due to men's activities like hunting leads to an imbalance in the functioning of an ecosystem and ultimately in the functioning of the whole biosphere. The formation of Sahara desert is an example of the ill effect of men's activities on the delicately balanced ecosystem.

Transfer of energy in food chains

The food chain in a community actually represents step wise transfer of food and the energy contained in food full stop the food and energy enter the living components of the ecosystem through the process of photosynthesis. This is because photosynthes is a process which combines the substances like carbon dioxide water and sunlight energy to form food like carbohydrates and Converse light energy of the sun into chemical energy of carbohydrates. This food and energy is then transferred from the producer organisms to herbivores and from herbivores to carnivores through the food chain.

First step

The green plants have a mechanism for trapping solar energy with the help of their green pigment called chlorophyll full stop the green plants after trapping the solar energy convert it into chemical energy which is stored as carbohydrates in the plants. The NaCl point where energy from the environment enters into the living components of ecosystem is the process of preparation of food by green plants through photosynthesis. On an average about one percent of the sun's energy falling on The leaves is used by the plants in the process of photosynthesis and stored as chemical energy in food. The plants utilise the energy stored in them for their metabolic activities full stop some of the energy is however not utilise and it is released as on usable heat into the environment.

Second step

The plants are eaten of by herbivores full stop the chemical energy stored in plant food is transferred with food to herbivores. The herbivores utilize this energy for their various metabolic activities like respiration and also for their growth. Some of the energy however remains on utilise which is released by the herbivores as heat energy to the environment.

Third step

Eaten of our consumed by carnivores full stop the chemical energy stored in the flash of herbivores is transferred with food to the carnivores full stop various metabolic activities and also for their growth full stop some of the energy remains and utilised by the carnivores and it is released as heat energy into the environment full stop this process of the transfer of energy is repeated with large carnivorous or top carnivores and so on. It should be noted that sum of the energy from producers and Consumers is also utilise for the life processes of microorganisms called decomposers full stop the decomposers inter release the utilised energy as heat into the environment. It is obvious from the above discussion that the energy which remains on utilised by producers consumers and decomposers is lost into the environment as heat. it is called community heat.

Ten per Cent Law

During the transfer of energy through successive traffic levels in an ecosystem there is a loss of energy all along the path. No transfer of energy is 100%. Yesterday's of transfer of energy in different food chain na large number of ecosystem has revealed a uniform pattern of transfer of energy which is given by 10% law. The 10% love which was given by lindaman in the year 1942 is one of the most useful generalisation about the magnitude of loss of energy in food chain. According to 10% law only 10% of the energy entering a particular traffic level of organisms is available for transfer to the next higher traffic lable.

Depletion of ozone layer

Vinod that oxygen is made up of two atom of Oxygen combined together. Oxygen gas is essential for life because it is needed in respiration. Ozone molecule is made up of 3 atoms of oxygen combine together. It is poisonous in nature. The free oxygen atom the produced are very reactive react with an oxygen molecule to form an ozone molecule:

   O2 + O-------- O3

 At the height between 15 km and 60 km there is a layer of ozone gas in the upper atmosphere full stop this ozone layer is very important for the existence of life on earth because it observe most of the harmful ultraviolet radiations coming from the sun and prevent them from reaching the earth full stop the ultraviolet radiation have extremely harmful effects on human beings other animals as well as plants full stop for example ultraviolet rays can cause skin cancer.

 It has now been found that the amount of ozone is getting depleted due to which the ozone layer in the upper atmosphere is becoming thinner and thinner day by day. The depletion of ozone layer is due to the use of chemicals called chlorofluorocarbons. Chlorofluorocarbons are the chemicals which are widely used in refrigeration as a coolant in fire extinguisher and aerosol sprayers. Chlorofluorocarbons released into the air react with ozone gas present in the ozone layer and destroit gradually. Due to this the ozone layer in the upper atmosphere has become thinner allowing more ultraviolet rays to pass through it to the earth does due to the depletion of ozone layer caused by chlorofluorocarbons more ultraviolet radiations reach the Earth. If the ozone layer in the atmosphere disappear completely then all the extremely harmful ultraviolet radiations coming from the sun would reach the earth. This ultraviolet radiation would cause skin cancer and other elements in men and animal and also damage the plants.

 Managing the garbage we produce

 The household wastage is called garbage. Every household producers a lot of garbage daily. This garbage includes left over food fruits and vegetables pills fall in leaves of water plants West paper unwanted plastic objects etc. Glass articles.

 Disposal of waste means to get rid of waste full stop that disposal of waste should be done in scientific way. There are different methods of waste disposal. The method to be used depends on the nature of the west. Some of the important modes of waste disposal are:

 1. Recycling

 The solid waste like paper, plastic, and Metals are recycled. For example West paper is sent to paper Mills where it is process to form new paper once again. The broken plastic articles like plastic bags buckets blouse cups plates etc are sent to plastic processing factors where they are melted and re molded to make new articles. Similarly waste metals articles are sent to metal industries where they are melted and recycled and solid metal for various purposes.

 2. Preparation of compost

 Biodegradable domestic waste such as left over food fruits and vegetables and leaves of potted plants etc can be converted into compost by boring in a feet dug into ground and used as manure.

 3. Incineration

 Incineration means reducing to ashes. The burning of a substance at high temperature to form ash is called incineration. Incineration is used to destroy household waste chemical waste and biological waste. Insulation greatly reduces the volume of the waste. This is because when the large volume of waste material is burned than only a small amount of ash is left behind which can be disposed of by land fill. 

 4. Landfill

 The disposal of waste by putting it in low laying areas of ground and covering it with earth is called landfill. Most of the solid waste in urban areas is dump in low laying areas of ground and covered with earth to level the uneven ground. A big land field site can be used to dispose of waste materials for a considerable time.

 5. Sewage treatment

 The dirty drain water containing urine and faeces which is carried from our homes by the underground pipes is called sewage. If untreated sewage is dumped into a river it can pollute the river water. The sewage is disposed by treating it at the sewage treatment plant. The treatment of sewage producers clean water which is discharge into the river. The organic matter present in sewage is digested in the digested of sewage treatment plant to produce sewage gas which is a kind of biogas and manure.