 So, good afternoon class, now we are going to start next topic that is types of cells. In order to understand that how many types of cells there is basically two classification. So, first classification which we have to study is on the basis of number of cells. What is the basis of classification? On the basis of number of cells. Second classification based on presence of nucleus as well as cell organelles. So, there are two places on the which you can classify the type of cells. So, first is on the basis of number of cells. So, in this basis we have two types of cells. First is unicellular and multicellular. You know these things, it is very easy. Unicellular, uni means one cellular means cell. So, those organisms which contains only one cell. For example, amoeba, paramecium, write down in your notebook also so that you can remember the name. Luglina, hemidomonas and many others. These are those organisms which are single cell organisms because they have only one cell that is known as uni cellular organism. Second is multicellular means more than one cell. So, it can be plants, animals and then as fungi also. So, always remember this multicellular which contains more than one cell. It means all the cells of this multicellular are arise from uni cellular. It means if there is one cell, this is uni cellular. But when you get divided into two and this two once again get divided into two, two then hopefully it will make four. So, from one cell four cells are formed. So, this is uni cellular but this four is multicellular. So, all the multicellular organisms are derived by the multiplication of the uni cellular. It means one cell, it is uni cellular when it gets divided it converted into multicellular. So, plants, animals and fungi are the multicellular animals. Now, second category on the basis of which you used to categorize the cells is presence of nucleus, presence of nuclear membrane or presence and presence of cell organisms. So, on the basis of this they are studying two types, karyotes different from uni cellular, multicellular. Pro-karyotes first of all keeping in mind they are primitive. They are very simply the starting phase or they are the simply starter when the type of cell was there. Then these are those cells which are the starting simply originating. You can say first phase of the cell. The pro-karyote means primitive and the eukaryotes advanced. Why did advanced? Because it is having much more features, much more characteristic as compared to pro-karyotes. So, pro-karyotes are primitive eukaryotes are advanced. Second point which we have to study in pro-karyotes is that they does not have nucleus or if the nucleus is there it will be not well developed. It means it will be in the diffused form. You cannot simply see in the microscope and say that this is the nucleus, it will not look well organized. Next there will be no plasma membrane and the last in this the cell organelles means the organs. You can say the bodies that is present inside the cytoplasm inside a cell that is known as cell organelles that have some structure and function and they will do different type of activity so that the cells can perform their basic metabolic function that is known as cell organelles. So, cell organelles is also not well developed. It means it is underdeveloped. No plasma membrane and one more point you can add cell organelles are not well developed. Next is eukaryotes. Eukaryotes means that is advanced. Now, how can you understand between primitive and advanced? Suppose there was a mobile phone before few years that was not having camera, does not have you can say Bluetooth, radio and all these features were not there. Basically camera was not there but that is you can consider it as a primitive because it was a starting of the manufacturing of phone. So that was the first mobile phone with less feature that is known as primitive. But as year after year there was advancement, there was some addition of new features like camera and nowadays there are so many cameras, very good magnification power and all these things. So many like Bluetooth is there you can talk using your earphone. Earphone is also a kind of advanced feature. So, simply you can understand the thing that is having less feature is known as primitive that is a starting and those who have that better features they have the across most of the qualities that can meet the human need that is known as advanced. So, eukaryotes is advanced cell prokaryotes are also known as prokaryotic cell and eukaryote is known as eukaryotic cell. Basically prokaryotes are the organisms which has prokaryotic cells means primitive cells and eukaryotes are those organisms which are advanced type of cells. So, next in eukaryotes you can learn nucleus is well developed. Second, nuclear membrane is also present. Third is cell organisms are also well developed. These are the advanced feature and that is why eukaryotic is known as advanced. So, I think you understood the difference between prokaryotes and eukaryotes. In next video we will study about the cell shape, cell size, cell number and cell volume that how many types of cell can be on the basis of this cell shape, on the basis of the size, on the basis of the number and then on the basis of volume. Basically number you know this UD cellular and multicellular which we discussed before. So, thank you.