in today's world where everyone is obsessed about differences and are fighting over it we forget the basic fact that all of us are made up of cells hello everyone welcome to manoch Academy in this video we are going to have a short introduction to the chapter sell the fundamental unit of life in 1809 Lamarck correctly pointed out that life cannot exist without cell and its structures the study of cell and cell structures increased and became deeper with the discovery of different types of microscopes the study of cell its structure and its functioning is known as cytology whereas when we study cell structure function genetics Etc we call that cell biology although cell is the basic unit of all living organisms different organisms show different cellular organization there are organisms which are unicellular here in these organisms all the functions that need to be performed by the organism to survive is performed by a single cell for example amoeba paramecium euglena or even a bacteria but then there are organisms where the entire body of that organism is made up of multiple cells so they are known as multicellular and here we see different kinds of organizations of the cell in multicellular organisms there are different kinds of cellular organizations for example in certain organisms which belong to phylum porifera for example sponge they have cells which are present together to form a multicellular structure but the cells do not form tissues in certain organisms we find that they are a little more evolved cells which have similar function and sometimes similar structure they come together to form an aggregate of cells that are termed tissues in these organisms tissues are formed where different kinds of cells performing the same function collaborate so that the work takes place more efficiently in more evolved organisms we find that the tissues of different kinds but aiming at a common function come together to form an organ we find organ formation in animals where the animals are a little more evolved than those with tissue grade of organization and eventually these organs together form a system for example your digestive system is made up of different kinds of organs like the liver stomach intestine rectum pancreas Etc if you go deep into the structure of each of these organs you will see that they are made up of tissues for example this wall of the stomach contains muscular tissue it contains connective tissue and it also contains epithelial tissue if you go deeper you will see that each such tissue is made up of cells so in every multicellular organism we find a certain type of cellular organization in your case you are the most developed organism as far as cellular organization is concerned and you have an organ system grade of organization now these cells that work together inside a multicellular organism forming tissues they have resulted in a more efficient system of working in living organisms think about it if you did not have a separate system for digestion and a separate organ for urine formation for example your kidney and each and every cell of your body have to do the same function of digestion and excretion would it be more efficient no so your something called division of labor comes into existence because of the cellular organization now we have organs which are specialized for respiration organs which are specialized for digestion organs which are specialized for excretion or even tissues that are responsible for protection this makes working of the entire human system or the system of any plant or animal much more efficient and therefore division of labor is extremely important at this point of time we know a lot about cells but scientists have been working on cells for more than three and a half centuries and with the advancement of the development of microscopes we have been able to dig deep and look into the different cell structures and subcellular particles but when did it all start zakarius Johnson in 1590 prepared the first simple microscope which consisted of one lens in 1665 Robert Hooke was the first scientist to observe a cell under a microscope he had made thin slices of cork which is a layer present under the bark of a tree and he observed it under the microscope you must have seen chord which is used as a cap in case of different kinds of bottles now this cork is a layer of dead cells we know that now how because the cells that Robert Hook observed under his microscope looked like Honeycombs they were empty without any liquid inside or a cytoplasm or a nucleus so he was the first one to observe these dead cells in a slice of caulk he named them cells which means small Chambers later in 1600s Anton van liuenhawk worked with glass he made lenses with different kinds of curvature and could come up with his own microscope which could magnify objects 270 times this was quite something at that point of time he observed a drop of pond water under his practical microscope but a simple microscope that he had created and he observed structures that moved at that point of time he had no idea that he was the first one who was observing living cells those were bacterial cells and that is why Anton van levinhawk is known as the father of microbiology later Robert Brown discovered the nucleus inside the cell purkinje coined the term protoplasm and different cell organelles were discovered with the advancement of a light microscope into an electron microscope so we understand that to observe a cell we need this magnifying apparatus which is known as a microscope all of you must have seen a microscope in your biology laboratory but do you know what the different parts of a microscope are for that I would want you to go and check out our video on parts of a microscope where a detailed structure of a compound microscope has been discussed despite Robert hooke's Discovery in 1665 cell was not yet recognized as the fundamental unit of life for more than 200 years in 1838 German botanist Matthias schleiden and German physiologist Theodore Schwann came up with the cell theory if you are a cell you got to have some common characteristic features one that cell is the fundamental unit of structure and function of all living organisms what does that mean it means that any living organism is made up of cells and the structure of that living organism is due to the structure of the cell and the arrangement of those cells in the body of that organism what does functional unit mean it means that all the cells perform their own function because of which a particular tissue or a particular organ or a particular system in an organism is performing its function so let's say if you ask your kidney to make you real without it cells it will not be able to do so first you will not have a kidney because the entire kidney is made up of cells second even if you have something to make the kidney the kidney will not be able to function because the specific cells of the kidney are responsible for the production of urine they have their work divided and very specific when we develop from one cell that cell usually is totipotent what is the meaning of this term totipotent totipotent means that this cell is an absolutely generalized cell it does not have any special function it can divide to give rise to more such cells and some of these cells will take up a special function and become specialized so when from a large number of totipotent cells cells of the kidneys were formed these cells became absolutely specialized to perform the function of urine formation so without these cells no other cell in the human body will be able to form your real so therefore cells are also known as the functional unit of life second all living organisms are made up of cells and their products so whatever your body is made up of all that is made by your cells or are yourselves three all cells are generally alike in their structure function in Biochemistry with minor differences so if you take a cell from your lung a cell from your heart and a cell from your kidneys they have basic similarities in their function they all have cell membrane they all have cytoplasm they have a nucleus they have some very common biochemical reactions going on in all of them despite that they also have certain special functions to perform so all cells might be alike in their General structure function and biochemistry but depending on what type of special function they are performing they might have differences in them or they will have differences in them three years prior to Rudolph virtual's introduction to cell theory that is in 1852 a renowned scientist from the same University that rudol birchaw belonged to which is the University of Berlin a scientist named Robert remake had made a similar claim on arrival of cells he had said that cells are generated spontaneously by cell division Theory at that point of time was not that well accepted when Rudolph vercha was asked about this similarity between the two theories and if this is a type of plagiarism he said that remix theory was published as an editorial and not as a real scientific paper given today's time even an editorial would mean that openness cellulite cellularly or that cells arise from pres existing cells is a theory that is given by remake and not by rudol virtual however as it stands we all know and accept that rudol birchaw had introduced this theory of ominous cellular esselily to cell theory all right so let me ask you one question can you tell me which is the smallest cell of the Living World do let me know your answers in the comments below looking forward to reading all your answers hope you enjoyed the video do hit the like button and share it with your friends if you did if you haven't subscribed to our YouTube channel hit the Subscribe button right now and click on the notification Bell do check out full courses on our website and Android App manoja Academy links are given 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