whoa look who's here hello grade 11 students welcome back to another exciting lesson about earth and life sciences all right let's do this grade 11 students my dear students are lesson two to earth systems you will have to explain that the earth consists of four subsystems across whose boundaries matter and energy flow specifically this module will help you to determine the four subsystems of the earth describe the characteristics of each sub-system trace the flow of matter and energy in the earth's subsystems and express one's internalized role as a steroid of the four subsystems concerning the flow of matter and energy before we dig into our new lesson let's have a short recap last meeting we discuss about the factories that make the planet habitable this oil location atmosphere size and mass magnetic field and presence of water fortunately earth has all of these factors so evidently it can support any life forms including humans we are all connected to each other biologically to the earth chemically to the rest of the universe atomically the code above is said by neil degrasse tyson an american astrophysicist do you agree with him why do you think he said that we are all connected a certain group of interacting interrelated or interdependent poets that work together to form a complex whole is called a system the scientists around the world try to study a planet through the smallest systems it have and fit them together to form a whole picture which is known as the earth system science specifically earth system is commonly referred as the spheres which are divided into four geosphere hydrosphere atmosphere and biosphere the natural interactions that exist among these subsystems make life possible on this planet in this lesson you will learn about the features of each of the subsystems and explain that earth consists of these four subsystems across whose boundaries motor and energy flow these four spheres regulate the different functions of earth which makes it habitable which is similar on how a human body system works all human body systems work together to maintain a well-functioning and healthy body on earth each of the four spheres or systems must keep itself in balance a change in one system will affect other systems here is the key concepts that you must remember on each earth subsystem number one biosphere this sphere is associated with living systems such as biomes or ecosystems this includes life on land in the oceans and rivers and even life that we cannot see with the naked eye organisms comprising the simplest cyanobacteria that the complex eukaryotes adopt their natural environment leading to survival even in extreme conditions such as extreme heat in the absence of water some unique plants and animals thrive by means of their evolutionary characteristics the atmosphere is filled with life in the form of philippine ego monarch butterfly vampire bat peregrine falcons and some flying insects the hydrosphere is steaming with life as well just like the blue whale the orca the starfish and the sea cow in fact most of the organisms or earth are found in water the features of biosphere are coastal biomes forest desert grasslands and other ecosystems different processes happen in the biosphere such as photosynthesis biogeochemical cycles like carbon cycle and nitrogen cycle the main source of energy for all life forms is the sun through photosynthesis producers manufacture their own food to produce carbohydrates the producers or autotrophs are consumed by the consumers in a food chain a series of food chain comprises a food web this illustrates that matter and energy flow within the system an interlinking food chain is called food web the constant flow of energy on earth is what allows life to perpetuate the second system is the hydrosphere hydros means water so the hydrosphere is composed of all the waters on earth such as liquid water found in oceans lakes and streams polar ice which is solid in form and water vapor that results from evaporation of liquid water earth is sometimes called the blue planet due to the presence of liquid water oceans occupy almost seven to one percent of the earth's water the other fractions are distributed as polar ice and water vapor energy from the sun heats up the ocean water and evenly due to the difference in the angle of sun's rays across different portions of the earth this causes difference in ocean temperature specifically the ocean water near the equator is warm while the ocean water near the poles is cold the difference in the temperature of the planet's water leads to the difference in density which causes water to move by means of convection the movement as a result of difference in density is called convection current which distributes energy in the ocean the different features in the hydrosphere are oceans icebergs lakes rivers glaciers snow and so on the different processes involving the hydrosphere are the hydrologic cycle such as condensation and evaporation and ocean circulation the atmosphere is the gaseous part of the earth composed of several trace gases necessary to support the existence of all living components such as plants and animals the atmosphere is divided into layers according to differences in the pattern of temperature as one goes to higher altitude from the bottom this are the troposphere stratosphere mesosphere and thermosphere though the atmosphere may be a very thin layer of the earth when compared to the earth's interior it plays a vital role in the maintaining the planet's temperature it acts as a thermostat ozone molecules in the stratosphere absorb high energy radiation by means of photodissociation weather occurs in the troposphere atmosphere plays a role in weathering of rocks making the earth dynamic the sun unevenly hits the air which leads to the movement of air molecules cold air sinks at bottom of the atmosphere where most life forms are found this is due to its high density hot air on the other hand rises up due to its low density this movement distributes energy in the atmosphere it is the movement of air in the atmosphere that causes weather and climate this table shows the descriptions of each atmosphere layer the troposphere air closest to the earth where we live where weather is formed and airplanes fly at the top of it it can be found 10 miles or 16 kilometers above the surface of the earth the stratosphere or ozone layer is part of it it helps shield the earth from harmful sun rays 30 miles to 48 kilometers above the surface of the earth is the position or location of the stratosphere the mesosphere is the coldest layer where meteorites break apart 50 miles to 80 kilometers above the surface of the earth while the thermosphere is 5 times as deep as all other layers combined it is very hot with up to 2000 degrees celsius temperature it can be found 200 miles or 483 kilometers above the surface of the earth lastly the exosphere where satellites circle the earth and fades into space it is beyond 300 miles above the surface of the earth here are the atmosphere features clouds weather aurora air pollution or aerosols thus and so on and the only atmosphere process is the atmospheric circulation next is the geosphere it is the solid sphere of the earth this is where different geologic processes such as volcanic activity formation of mountains volcanoes and other geologic structures take place the lithosphere is a part of the geosphere that is composed of the solid outermost part of the planet it is where tectonic plates that move are found causing the ground to move through vibrations of energy from the mantle and those vibrations are called earthquakes because of fluvial and alluvial processes delta canon river channels are made and for the aeolian processes the geosphere features that are made are sand dunes and iodines as the result of tectonic processes we can have folds faults and mountains for volcanic processes involved in the geosphere we have volcano central vent and volcanic deposits other geosphere processes are weathering mantle convection and erosional process moving on we have the earth's interior layers i know you are all familiar with this but let's have a refresher the crust is the upper portion composed of two types the oceanic crust that underlies the ocean basin and continental crust that underlies a continent which is most abundant composition is oxygen and silicon the mantle is the solid rock layer between crust and core and the core is an iron-rich sphere divided into two parts the outer core which is liquid and composed of ion nickel sulfur generates magnetic field and the inner core which is predominantly made up of solid iron and nickel alloy yay we already finished the lesson two congratulations and thank you for listening please accomplish the following activities related to this lesson thank you so much keep safe and stay at home you