 Happy Republic Day in advance, Surya. So let us start the new chapter that is our environment for revision. From this chapter, 4 to 5 questions, 4 to 5 marks questions will come in the form of very short, short and then long, okay? Can we start? Everybody ready? Aditya has also admitted in the class. Is it okay? Should we start? Shall we start? Everybody say yes or no. Close the chat box. Okay. So without wasting time, let us start the first chapter R environment, the first chapter of today's lecture. First of all, what is an environment or what is an ecosystem? Let me open this participant list so that I can allow you to sign in. So here is what is an ecosystem. Before ecosystem, I would like to tell you that what is an environment. Environment is something that is present in our surrounding. Environment is something that is present in our surrounding that is known as environments. Related to that is an ecosystem also. What is an ecosystem? An ecosystem is a self-sustainable, structural and functional unit of life. What is an ecosystem? An ecosystem is a self-sustainable, structural and functional unit of life or a sustainable structure or functional and unit of biosphere you can say in which all the life is existing. So what is an ecosystem? An ecosystem is a self contained unit of living things like plants, animals and decomposers and they are non-living environments. It means biotic components will be also there and a biotic components will be also there. Let me check is there anybody else who is trying to join the class? No. Okay. I am audible properly. Am I properly audible? So what is an ecosystem? An ecosystem is a self structural functional unit of biosphere in which biotic as well as a biotic components interact with each other. So biotic is living. A biotic is non-living. Living and non-living. So if we talk about the living so it will be plants, animals, humans and non-living it will be soil. After this we can say water. All the non-living components will be present in the surrounding that is going to you can say established relationship with the living component. For example, I am living in this ecosystem. I am inhaling oxygen. I am giving CO2. I am using the soil to make my plants grow. I am drinking water so I am interacting with non-living things. It means I am interacting with a biotic components. So I am biotic. I am interacting with a biotic so that will constitute an ecosystem. Any doubt? Any doubt class? Only Surya is replying that no doubt. This is the example of ecosystem. What are the examples of ecosystem? The examples of ecosystem are grassland ecosystem, forest ecosystem, desert, mountain, pond, lake, river and sea. These all are small, small, small ecosystems. Is it okay? So most of the ecosystem in the world are natural. For example, these pond, river, sea, forest, desert, these all are natural ecosystem but at the same time we can go with the man-made or artificial like aquarium. So aquarium is the ecosystem that is man-made or artificial. Is it okay? Artificial ecosystem it is already given here. I am waiting for your reply. I think somebody to use the mic like agricultural lands, parks and aquarium. They are built by the man-made. They are built by the you can say by the involvement of human activities. So they are known as artificial ecosystem. Next is what is the contents of the presentation? So first is components of an ecosystem, functioning of an ecosystem and these are the factors or you can say main important component of the ecosystem. These are all things we have to study. In components of an ecosystem we can see the abiotic components. What it is? First of all, the component is abiotic. Abiotic means non-living components of an ecosystem include physical environment like soil, water, air, carbon dioxide, nitrogen and oxygen. These are abiotic. I have already told you like water, phosphorus, sulfur, sodium, all the minerals and all the nutrients. After this the physical factors or climate factors like light, temperature, pressure and humidity. So all the physical factors that includes climatic factor also like light, temperature is there, pressure is there, humidity means amount of water vapor present in the environment. They all will become abiotic components of the ecosystem. The abiotic component or living component of an ecosystem is a community of organism like plants and animals which is made up of many different interdependent populations. So abiotic component means living components. Abiotic means non-living component. The abiotic community or living world of an ecosystem includes three types of organism. First is producer, consumer and decomposer. Producer, consumer and decomposer. Producer that will produce something that is known as autotrop. Consumer that will consume the producer that is known as heterotrop. Decomposer that will eat the dead and decaying material that is known as saprotrop. They are also known as natural cleaner of our body. Okay. So moving to the next functioning of an ecosystem. How does this ecosystem function? What are the components? Then how it will function? Self-sufficient. It means it is self-dependent. Ecosystem function has a self-sufficient or independent unit in nature. Ecosystem has both living, non-living, abiotic, abiotic. All these components make the ecosystem function as follows. How it will function? See clearly. Hello class, can you hear me? Now have you heard anything? I was explaining the function of the ecosystem. Can you hear me now? But is screen invisible? Now you can see the screen. Hello. Now screen is visible. My voice is clear. Okay. So see here once again ecosystem will function as a self-sufficient, self-dependent. It's not dependent upon others. Someone is trying to add. Hello. Okay. Now here is the writing pad. Now I can see the chat as well as the person who are entering in the class. Ecosystem will function as self-dependent or independent unit in nature. Ecosystem has both living component as well as non-living components. All these components make the ecosystem function as follows. Like from the nutrient pool of earth. Earth is considered as a nutrient pool. Nutrient pool means it have all the nutrients. So I will have water there, air is there. So carbon dioxide that is present in the nature and water that is present that will be absorbed by the producer. Okay. So green plants what they will do? Green plants will have chlorophyll by the help of sunlight energy they will produce food. This glucose will be food. It means I am talking about which process? Photosynthesis. So the green plants will do photosynthesis and by the help of photosynthesis producer traps the solar energy and then provide the basic food or energy for all other life forms in the ecosystem. It means the help of the photosynthesis plant will prepare food and that plant will be eaten by consumer. So consumer will get the food then consumer will also die after some time. It will be consumed by saprophytes like we can say saprophytic mode of nutrition will be there. In this way saprophytes will also get the food. In this way producer, consumer and decomposer all of them will get the food. Is this clear? You don't know. In the last we will discuss the question also that was the part of the last year. Producer, consumer and decomposer one by one. Everything is very easy. Chapter is students. Producer means something that will produce something. Producer has an organism which can prepare their own food from simple inorganic substances like carbon dioxide and water by using sunlight energy in the presence of chlorophyll. It means we are discussing four synthesis. Producer will do photosynthesis. The examples are green plants and blue green alga. Moving to the next. Those organism which consume food. Those organism that will consume food that will eat food prepared by the producer are called consumers. All the animals are consumer. Even we can add human is the intelligent intelligent someone is trying to add. Okay. So human is also one of the animals that we are also consumer. If an animal eat grass or other green plants or their product itself we say that it gets the food from producers directly. So what the animals suppose animals are eating green green grasses that is a part of producer then these green grasses will go in the body of producers and produce from producer it will go to consumer. If an animal eats the meat of another animal suppose there is an animal that will eat the meat of another animal which get eat grass then we can say that energy is going from producer indirectly. If an animal eat the meat of another animal for example if my name is Archer I eat meat meat of goat goat is eating green grass goat is eating green grass okay. Then we say that it gets the food from the producer indirectly. It means the food we I am getting the food from the producer only but not directly I am getting indirectly. Is it okay? Yes or no? Okay. So consumers can be further classified as herbivorous, carnivorous and omnivorous. So consumer may be of how many types? Three types herbivorous, carnivorous and omnivorous. Now let us study one by one herbivorous. Those organisms which will eat only herb and shrub this is such a basic thing everybody know they eat grass, leaves, grains, fruits or bark of the tree that is cow, buffalo, goat, sheep, horse, deer, camel, ass, ox, elephant, monkey, squirrel, rabbit, hippopotamus okay all these things. Next is those animals which eat only other animals as food are called carnivorous. So those animals which will eat only other animals like lion will eat deer, goat they are known as carnivorous like lion, tiger, frog, vulture all the example have been mentioned directly here. The small now next is the small carnivorous which fed on herbivorous are called primary consumer are called secondary consumer. Now in order to understand this slide children for example if I say that this is green grass just a second suppose this is green grass. Now green grass will be eaten by rabbit, rabbit will be eaten by suppose lion instead of rabbit it could be goat also. Lion will be eaten by saprophytes talking to more examples suppose green grass is eaten by what can we say now green grass is eaten by suppose goat, goat is eaten by human, human is eaten by lion. So here we can say this is primary consumer green grass is a producer so prime goat is a primary consumer human is a secondary consumer okay and lion is eating the secondary consumer it will become tertiary consumer any doubt in the explanation of primary secondary and tertiary consumer out everybody reply that is there any doubt yes or no no doubt okay so let us go back and continue our topic those animals which eat both plants and animals those animals which will eat both plant and animals are called omnivorous okay those plants are known as omnivorous like man, dog, crow, sparrow, bear, man and ant are omnivorous everybody please write down these things these examples are very very important it will come in a short answer question. Plantons are very minute or microscopic organism freely floating done the surface of water in a pond lake river or ocean I hope you can see the diagram and then you can imagine that these are green green color plantons these are very minute very very minute these are very very tiny microscopic organism freely floating on the surface of the water plantons can be two type plant it can be animal so phytoplankton, jouplankton the microscopic aquatic plants freely floating on the surface of water are called phytoplankton like algae green green algae that is doing photosynthesis also next is the microscopic aquatic animals freely floating on water known as jouplankton like protozoa so animals will be in jouplankton and we can say green plants will be a part of phytoplankton is it okay Janya is trying to admit are you guys writing phytoplankton the green layer floating on the surface of the water in this lake is that of tiny free floating plants called algae which are phytoplankton so everybody I have understood you made you understand that what is phytoplankton and what is jouplankton okay the green layer floating on the surface of water of the lake is phytoplankton tiny aquatic animals freely floating on water is called jouplanktons next is decomposer the microorganism which break down the complex organic compound present in dead organism like dead plants and animals and their product like pieces urine etc into simpler substances are called decomposers okay so they are known as decomposer that will depend upon the dead organism dead plants dead animals the bacteria and fungi are best example the bacteria and fungi which decompose the organic matter present in the dead plant and animal into simpler substances and liberate ammonia carbon dioxide etc the bacteria which acts as decomposer are called putrifying bacteria this is important so putrifying bacteria are decomposing bacteria decomposing bacteria decomposer help in the recycling of material in ecosystem the decomposers are also known as micro consumer or sapro tropes okay and the mode of nutrition is known as saprotropic mode of nutrition or it is also known as saprophytic mode of nutrition is it done now what is the importance of decomposer the decomposers help in decomposing the dead bodies of plants animals and they are known as natural cleaner cleansing agent of the environment it is only due to presence of decomposers that the various nutrient elements which were initially taken by plant from the soil air and water are returned to the soil air and water after the death of plants and animals the decomposer of organism they will help in recycling the material in the ecosystem so that the process life go on like an unending chain so decomposer are very important because they whatever they will consume they will give it back to the environment so that our environment will become neat and clean is there any doubt in this are you listening class let me go back to the chat box no doubt now next is food chain the process of eating and then the food chain that is moving from one direction to another direction means the process of eating something and the organism that is eating something is also eaten by another organism the movement of energy will be in one direction that is known as food chain so what is food chain what is food chain food chain is the sequential interlinking of organisms food chain is a sequential interlinking of organisms involving transfer of food involving transfer of food energy from the producers though a series everybody please write down this definition though a series of organisms with repeated eating and being eaten eating and being eaten is called the food chain is called the food chain for example producer producer will be consumed by herbivorous herbivorous will be by primary carnivorous then this is by secondary carnivorous secondary carnivorous by tertiary carnivorous so producer primary consumer secondary consumer tertiary consumer and this tertiary will leads to quaternary consumer okay this way the food chain will go the movement of energy is always in one direction that is known as unidirectional everybody can you hear me yes or no okay tropic level the various steps that are representing organisms in a food chain at which the transfer of food and energy takes place are called tropic level so what is tropic level suppose green plants are eaten by producer so producer will be first tropic level because green plants are giving energy to producer the producers are getting 10% of the total energy now the producer will be eaten by consumer so consumer will be second tropic level second tropic level is getting 10% of the total energy that is present in the producer is it okay no I am not writing anything I am speaking I am audible I should write should I write okay okay let me write so here is producers primary consumer secondary consumers tertiary consumers after this quaternary consumer and then seprofites so producer to primary consumer the flow of energy is unidirectional it means the flow of energy in this food chain will be in one direction after this it will be secondary consumer tertiary consumer quaternary and then seprofites so what is this this is first tropic level second tropic level third tropic level fourth tropic level these all are the tropic levels and this is the fifth tropic level so producer will give whatever the energy is produced in the producer suppose these are green plant they are producing energy so only 10% of the energy will go in primary consumer whatever the energy is present in primary consumer it will give its 10% already whatever the energy is present in the secondary consumer it will be given into the tertiary consumer the same thing 10% then here is also 10% so only 10% of the energy is passed at each successive tropic level this is known as 10% law that was given by a scientist known as lindman is it okay 10% law was proposed by lindman in 1942 in 1942 any doubt no doubt now we will understand what is the characteristic of food chain food chain is nutritive interaction a food chain is always this trait food chain unidirectional flow of energy will be there only three to four tropic levels are there in a food chain not more than four tropic levels means in a few it can be five but normally for a you can say normal we can say if we talk about an ideal food chain it have only three to four tropic levels some organism can be omnivorous some organism can be carnivorous some organism can be herbivorous at each transfer generally 80 to 90% of the energy is lost as heat in accordance with second law of thermodynamics is it okay of one of the important topic is bio magnification bio magnification is a magnification bio magnification means biological magnification bio magnification or biological magnification in this the thing is that if there is a supposed food chain plant producer consumer decomposer suppose this is a food chain now in this food chain there will be successive transfer of energy there will be a successive transfer of energy in the form of food chain so along with the energy there are some harms full things like DDT heavy metals after this mercury arsenic cadmium DDT heavy metal mercury arsenic and cadmium these all are the five harmful things they can also be transferred from one tropic level to another tropic level it means from one step to second to third to fourth so this will be first tropic second tropic third tropic level and what will happen if they will pass their concentration their concentration at each tropic level will go on increase 0.05 0.1 0.2 like this the concentration will go on increase at each of the tropic level this is known as bio magnification or biological magnification for example in a food chain operating in a pond river or lake the water contains a small amount that is 0.02 parts per million it means water have a small amount I if I talk about a pond aquatic ecosystem in water there is 0.2 parts per million fish will consume it how the fish will consume to consume before fish first of all there will be phyto plankton jute plankton they will consume something now these phyto and jute plankton are consumed by fish so they will also consume something so fish are feeding on these accumulate 240 parts per million so in this way what will happen at successive tropic level the concentration of harmful chemicals will go on increasing is it okay I am audible or not any doubt any doubt in bio magnification no doubt now one more thing is utrophication utrophication is means aging of the lake okay aging of the lake lake aging okay what is this in utrophication what will happen all the green color phyto plankton will be grown and just because of this suppose this is a pond this pond will have a small small fishes this is water this is fishes and these fishes will have they will be covered by growth of phyto plankton and outside there is solar energy that is known as sun okay so this sun that is a solar energy that is used by the phyto plankton to do photosynthesis to make their food but what about these poor fishes poor aquatic animals that are at the bottom of the sea or just below the or just below this phyto plankton is there any disturbance okay so utrophication is this process in which the phyto plankton will cover the entire water source either it is lake or it is pond and the internal organism that is at the bottom of the sea or the bottom of the pond they will not get sunlight and just because of the lack of sunlight they will not prepare their food they will not get their food they will not get proper nutrition nourishment and they will die this is known as utrophication what is this known as utrophication is it okay now next is what is left in this chapter now the last part of the chapter is ozone as well as waste management a small topic is there ozone everybody know the formula of ozone is o3 ozone will protect the earth from the harmful UV rays if there will be no ozone layer all the UV rays will come inside the earth and then they can cause several diseases like skin cancer eye cancer cataract first ozone hole was observed in Antarctica that is in 1985 so how can we write first ozone hole was discovered in Antarctica in 1985 okay what is ozone hole it doesn't mean that there is a huge hole it's simply means that the ozone layer is becoming thin it's getting depleted day by day is it okay yes correct Surya so this is known as ozone hole that is also known as ozone depletion first ozone hole was observed in Antarctica in 1985 what is the depletion what is the effect of ozone depletion first is cancer eyesight weak will be there weak eyesight immune system will be poor increase the embryonic mortality photosynthesis global warming decreased photosynthesis would result in increase in the concentration of CO2 that is known as global warming everybody know what is global warming the earth will become warm the concentration of CO2 will rise this is known as global warming is it okay any doubt now next is biodegradable and non biodegradable waste so biodegradable waste are these ways can be degraded by biological or microbial actions these includes domestic sewage livestock waste municipal waste these cause pollution only when they are added in the large amount then their rate of degradation non biodegradable these waste are not acted upon the microbes or acted upon very slowly so that they cannot be degraded so waste are basically two type biodegradable it means that can be that can have the action of microbes non biodegradable that does not have the action of microbes is it okay yes or no now let us discuss the question part short answer type questions as you can see I have some questions along with their answers what is environmental pollution distinguished between biodegradable and non biodegradable pollutants choose the biodegradable pollutants from the list given below so first of all what is environmental pollution environmental pollution is an undesirable change in the physical chemical or biological characteristic of the natural environment okay what about by man's activity this pollution may affect the soil they can affect the river they can affect the seas or they can affect the entire atmosphere so you have to only give the definition of environmental pollution you don't have to write all the things now how you will distinguish between biodegradable and non biodegradable we will make one column like this make a line in between these pollutants can be broken down into non poisonous substance in nature by the action of microorganisms non biodegradable can't be broken biodegradable can be recycled non biodegradable cannot be recycled biodegradable generally obtained from living things non biodegradable are generally not obtained from living things fourth they cause minimum environmental pollution non biodegradable cause most of the environmental pollution is it okay okay so see the questions once again question number one part two part three choose the biodegradable pollutant from the list given below sewage DDT radioactive waste agricultural waste so what will be there biodegradable pollutants are sewage and agricultural waste material is it okay yes or no this is how is the increase one more question see in we have to only write the answer in one or two lines how is the increase in demand for energy affecting our environment adversely the increase in demand for energy effects are involvement adversely due to this increase pollutants like carbon monoxide carbon dioxide sulfur dioxide these all are released into the atmosphere which leads to which leads to greenhouse effect two line answer okay for short answer for one more question only you have to write two line answers high is ozone layer getting depleted at higher levels of the atmosphere so ozone layer is getting depleted at the higher level level of the atmosphere due to the effect of chlorofluorocarbons CFC everybody know chlorofluorocarbons that is released from AC refrigerator they are very dangerous name any two abiotic components of an environment the two abiotic components of an environment are temperature and rainfall instead of this you can also write children air and water okay air and water are also two abiotic component of the environment can you explain the types of waste management like there are some like fire method and all that but it's not in our syllabus are in this time board does not have the waste management type primary treatment secondary treatment tertiary treatment there are so many treatments methods of solid waste disposal understood now next question I will discuss each of the question last year questions why are bacteria and fungi called decomposers list any two advantages is list any two advantages of decomposer to the environment so bacteria and fungi break down the dead remains and waste product of organism these microorganisms are called the decomposers as they break down the complex organic substances into simple inorganic substances okay so that is why bacteria and fungi are also known as saprotrops saprophytes decomposers two advantages of decomposers in this environment are as follow decomposers feed on the dead bodies of plants and animals they return the simple components to soil and help in making the steady state of ecosystem by recycling of the nutrients okay they therefore create a balance to the environment they also act as scavengers or cleansing agents of the atmosphere okay what are the two main components of our environment the two main components of our environment are biotic or living component as well as a biotic and all living see whatever question that is of one mark only that is only of one or two line answer is it okay only arian is replying what about other students why are green plant produce called producers okay now i am not i will not give you the answer you have to give the answer our plant called producers such a easy questions plants are called producers as they can prepare their own food by the process known as photo synthesis very nice very good next is which disease in human being is caused due to depletion of cojone layer in the atmosphere already you can see the answers cancer the answer is given here only so you can directly i can i think that you can directly see the answer and tell me okay now one more board question i'm going to ask okay the question is suggest any four activities in daily life which are eco-friendly any four activities group any four activities not using plastic very good anirudh after this using chute and cloth bag reducing the usage of water using a bucket instead of shower okay very good very nice next is what will be the consequences of absence of decomposers in an ecosystem rain water achha very nice saryan what will be the consequences what will be the consequences or absence of decomposer in an eco system in absence of decomposer dead remains having nutrients will not be restored to the soil the earth will be accumulated with stinking saracas okay okay okay next is everybody listen carefully i am asking more board question what will happen if we kill all the organism in one tropic level suppose there is a food chain and in one tropic level in any of the one suppose i am killing all the organism what will happen then the food chain will collapse and organism of other levels won't be able to live very good it will disturb the food chain and food web which in turn will decrease the chances of food availability in the succeeding tropic levels and finally result in instability of the eco system is it okay is it okay next is the same question is given here let me complete the question which i have used in my PPT explain the phenomena biological magnification how does it affect organism belonging to different tropic levels okay so such an interesting part here is this the second part that how does it affect organisms belonging to different tropic levels particularly the tertiary consumer the process in which harmful chemicals enter a food chain and get accumulated progressively at each tropic level is called biological magnification so harmful and toxic chemicals enter our bodies when they are added to soil and water use of pesticide to protect the food crops from diseases and pest and chemical waste of factories are dumped in open or disposed of into rivers the quantity of these harmful chemicals increase with increase in tropic level so what will happen suppose there is continuously biological magnification accumulation of DDT is taking place the i-chlorodiphenyl trichloroethane is the full form of DDT that will get accumulated in the following way in the food chain this is the reason why our food grains such as wheat and rice vegetables foods all these things will be what all these things will not be have proper amount of nutrition so we will eat chemicals we will not eat nutrition is it okay see here is one of the example also given water phytoplankton and then fish 2 marker 2009 how is ozone formed in the upper atmosphere why is the damage of ozone layer cause of concern to us state a cause of this damage ozone is formed in upper atmosphere by the reaction of ultraviolet rays to oxys and the damage of ozone layer is cause of concern to it because more UV rays reach the surface causing more disaster see this is O2 O2 will combine with one O it will become O3 that is ozone a cause of this damage is the presence of large amount of chlorofluorocarbon in the atmosphere is it okay damage to the ozone layer is a cause for concern suggest any two steps to limit this damage very easy question first you have to see whenever you are answering any question that have two questions means that question have two part so try to answer first part of the question in one paragraph and then the second part of the question in another paragraph so that it will be easy for the examiner to know that yes you have given answer to both part of the question it's not like that use only a single paragraph so many lines to describe all the parts of the question no you have to try you have to try that you should give the answer in two different paragraphs so that it will be clear that yes one part is now this and then after this part is next paragraph if you give the answer in the form of points like one two three that will be more useful now next question that I would like to ask is what are the various steps in the food chain known as what are the various steps in the food chain known as tropic level very good next question I hope everybody is ready to give me the answer tell me the full form of DDT tell me the full form of DDT tell me the answer okay the flow of energy in a food chain is DDT full form still I am waiting next board question is there the flow of energy in an ecosystem is Aryan has given the correct answer because his spelling is correct T-R-O-P-H-I-C okay Aditi very good Aditi unidirectional anybody who is going to tell me the full form of DDT sorry di chloro di phenyl tri chloro ethane very nice I have googled it Aryan okay you are very honest I appreciate it but try to learn this spelling is it okay try to learn the spelling next question the few questions I have on my screen let me discuss this what are the important function of presence of what is the importance of presence of ozone in the earth atmosphere it will protect us from the harmful UV rays okay give an example to illustrate that indiscriminate use of pesticides may result in the degradation of the environment the pesticides used in crop field are washed down into the water bodies from water bodies these are absorbed by aquatic plants and animals of a food chain and thereby degrades the environment why is it necessary to conserve our environment it is necessary to conserve our environment to prevent depletion of natural resources and environmental damage thereby sustaining life okay now what is meant by biodegradable waste that can be broken down into simple simple pieces by the biological processes okay example are urine, fecal matter, sewage, agricultural residue, paper, wood, cloth as well as cattle done is it okay next question next question I would like to ask differentiate between food chain and food web differentiate between food chain and food web differentiate between food chain and food web then give an example to the food web okay very good Aryan I have seen your answer give an example to illustrate that indiscriminate use of pesticide may result in the degradation of the environment the pesticide used in crop field are washed down into the water bodies from water bodies these are absorbed by aquatic plants and animals of a food chain and thereby degrades the environment next is why is it necessary to conserve our environment it is necessary to conserve our environment to prevent depletion of natural resources why is it important because we have to conserve our natural resources depletion of natural resources and environmental damage thereby sustaining life what does mean by biodegradable waste already we have discussed those ways that can be broken down into simple simple pieces now I once again I am asking class do you have any doubt okay now one more question I would like to ask and I want everybody to answer in the chat box everybody means everybody describe biomagnification describe biomagnification everyone have to write the answer in the chat box the phenomena due to which non-biodegradable substances continuously accumulate in increasing tropic level in the food chain is called biological magnification very good Aryan has given such a beautiful answer in so less lines Aryan answer is also correct Sreyesh Aditi instead of waste you can use toxic materials or biodegradable non-biodegradable substances concentration of impurities and toxins like DGT increase as we go up a food chain since they are not biodegradable this is called biomegification very good very nice I hope you have understood this chapter any doubt everybody okay one more question let me ask only last question what do you mean by uterification what do you mean by uterification uterification are you guys hearing me please write down the answer the excessive development and formation of layer of phytoplankton over stagnant water body is leading to resistance to normal functioning of underwater aquatic life is called uterofication very good Aryan but your spelling of uterification is not correct it should be E U T R O after that it should be P H I C A T I O N uterofication is it okay okay so very nice everybody bye bye take care this was the revision class of our environment chapter please go through the slides go through the last year question that are going to use use in the board examination surely okay bye bye take care bye bye everybody thank you