hello friends welcome to expert guidance today in this video we'll be covering the topic the cell biology EQ GCSE paper 1 biology so to remind you for your paper 1 you need to cover the cell biology organization infections and response and bioenergetics and this video is focusing just on the topic cell biology in this video we'll be looking over a eukaryotic cell and a prokaryotic cell animal cell and a plant cell specialized plant cells specialized animal cell microscopy culturing micro organism cell division mitosis stem cell diffusion osmosis and active transport it's a bigger unit with a lot of important topics so make sure you understand them well ok so I'll try to make it easier for you now the first thing we need to know is what is the difference between eukaryotic and a prokaryotic cell now prokaryotic cell is a bacterial and eukaryotic cells are plants and animals now if you see in this diagram there is a eukaryotic cell and a prokaryotic cell the first basic difference between the two is the presence of this structure called the nucleus the nucleus is present in a eukaryotic cell but in a prokaryotic cell the nucleus is absent apart from the nucleus eukaryotic cell you can see they have those organelles which have membrane around them so all membrane bound organelles are present in a eukaryotes example mitochondria but these membrane bound organelles are absent from a prokaryotic cell the next difference is since the nucleus is absent in the eukaryotic cell the DNA is enclosed in the nucleus but in a prokaryotic cell it lies naked in the light cytoplasm added as it has no nucleus the eukaryotic cell are mostly multi solla but the prokaryotic cell are mostly unicellular the eukaryotic cell DNA's linear but prokaryotic cell DNA is circular both eukaryotic and prokaryotic cell has ribosomes but in a eukaryotic cell the ribosomes are baked in a prokaryotic cell they are small eukaryotic cell a multicellular big cells breast food carry on Excel a small unicellular cells example is a plant cell on an animal salafi eukaryote and for a prokaryote there's a bacterial cell so I hope you're able to write these differences because in the exam they can ask you to let you know any two differences or any two similarities between a eukaryotic cell and prokaryotic cell so make sure you understand these points next is let us look at in detail the structure of an animal cell now the diagram here shows you the animal cell and you can see there's around big nucleus the jelly-like fluid that folds the cell is the cytoplasm the outer layer that surrounds the cell is a cell membrane and then in these structures on them and freely you have ribosomes and then you have these pink structures called the mitochondria now you should know these names and the functions of each as these are found both in plants and an animal cell so the first is a nucleus it is the brain of the cell because it controls all the activities it controls what is happening inside the cell and it also has your genetic information as it contains the DNA so you should know all these three functions of the nucleus next is a ribosomes ribosomes are the site for protein synthesis now the cell needs proteins for its functioning and you know enzymes are also protein so ribosomes they make proteins and the enzymes which are required by the cell next is the cytoplasm the cytoplasm is like the jelly-like fluid which fills the entire cavity of the cell it is very important part because it has all the enzymes for the chemical reactions of the cell so majority of the chemical reactions of the cell takes place in cytoplasm next is a cell membrane as it's the outer layer so as it's the outer layer it is controlling what is going in and out of the South and mitochondria is very important it is a powerhouse of the cell power house means it provides the cell with the energy as it is the site where aerobic respiration takes place okay so I hope you know the function of each of these organelles okay and you should be able to label them if any cell is given to you you should be able to spot where's the nucleus with the cell membrane where's the mitochondria next is a plant cell now the plant cell has all these organelles which we have just discussed in the previous slide except it has three extra girls which are just found in a plant cell they this is a big large permanent vacuole these green structures called the chloroplast and outside the cell membrane there's an extra layer called the cell wall now the permanent vacuole you should remember the function of each one of them the permanent vacuole is filled with the salsa and it gives rigidity to the cell and makes the cell turgid the cell wall is the outer layer and it is made up of cellulose you should remember the cell wall off the plant cell is cellulosic it is a layer outside the cell membrane and it supports the plan and maintains its shape the chloroplast is the site of photosynthesis because it contains a green pigment called chlorophyll which absorbs sunlight and converts it converts the light energy into chemical energy making food okay so you should know the difference between an animal cell and a plant cell so this is a table that summarizes a difference in both plants and similarities in the exam they can ask you to you know give to similarities or to differences so you should know both similarities and differences in both of these cells so both are eukaryotic the nucleus is present in both of them cell membrane is present in more than them mitochondria is also present in both of them ribosome is also present in both of them and cytoplasm is also present in both of them but cell wall vacuole and chloroplasts is present only in the plant cells so it is absent in an animal cell and it is present in an animal's in a plant cell ok so this difference is very very important next is the bacterial cell you should know a typical prokaryotic cell which is a bacterial cell make sure you can label it so you can see this tail like structure which is the flagellum which helps the bacteria to move then it has a cell wall and the cell membrane but the cell wall is not made up of cellulose you have to remember here it is made up of peptidoglycan then outside the cell wall you see a slimy layer which is a capsule and this capsu protects the bacteria and you also see some hair like structures outside this cell wall these appendages helps the bacteria to reproduce okay then since it has no nuclear the DNA circular and it is found naked in the cytoplasm and it has some extra chromosomal material you can see here they have plasmid the plasmids are the extra chromosomal materials which are found in the bacteria so you can see these extra stretches of DNA these are plasmid and they are in the form of small rings and they give special properties to bacteria like antibiotic resistance okay so I hope these all organelles thus labeling and their functions are clear to you okay so now this is our similarities and the differences between the bacteria plant and an animal cell bacterias prokaryotic plant and animals are eukaryotic the nucleus is absence in bacteria but present in both plants and animals our cell wall is present in bacteria but non cellulosic remember in a plant cell this cellulosic in animal cell it is completely absent cell membrane is present in all in bacterial ribosomes are smaller but in plant and animal cell they're bigger DNA is a circular in bacteria but linear in plant and animal cell the genetic material in bacteria is naked found in the cytoplasm in plant it is in the nucleus inside the chromosome and same in animals the chloroplasts are absent in the bacteria but they are present in the plant and animal cell and the vacuoles are small in bacteria but in the plant and animal cell they are absent in the animal cell but present in the plant cell ok so I hope the similarities between bacteria plant and animal cell and the differences they are clear to you ok so next in your syllabus there's a topic on order of magnitude now what is order of magnitude they'll give you the size of the two cells and then they'll ask you what is the order of magnitude of the two cells so what you need to do is you need to divide the size of the two cells okay and that will give you an order of the magnitude so for example if once is let's say the 10-meter and the other cell is let's say hundred meters right so you divide the two size so you will get the answer as stands so it means that one cell is in the order of magnitude ten than the other okay so for that it is very important the units are same so in the exam they can give you one in meters another in nanometer one is in micrometer another millimeter so you should remember this conversion so this conversion is simple it comes as a chart killing metal Milo Mickey nano pictures okay so killing metal Milo Mickey nano pictures it's kilometres meters millimeters micrometers nano meters and pico meters and all are at the level of 10 to the power 3 so kilometers to meters times per thousand times by thousand times 5000 and when you go reverse you need to divide by thousand so for example if you need to convert the nano meter into meters so you are going from here to here so you will divide it by 10 to the power 9 okay so one nanometer is one time Sentai minus 9 meters so you can remember this table and this is a mnemonic to remember it so if it is 10 nano meter 2 meters so for man o meter 2 meter what do you do you divided by 10 to the power 9 so that becomes sin by minus 8 meters and micro meters 2 meters so micro meters 2 meters is 1 to 2 bumps so it means divided by 10 to power 6 so that gives the answer then power minus 5 meters so it's very important you know how you need to convert make sure both the units are same and then divide the two okay now the next thing we need to do is what are the specialized animal cells now what are specialized animals are now specialized animal cells of those cells which have some two extra features that allow them to perform their specific functions okay now what do you need to do for each of these cell type you need to know what are the functions of each of these sulci and depending on the functions what structural characteristics they have so for example a nerve cell what is the function of the nerve cell to send electrical impulses around the body now this is the structure of the nerve cell and in this nerve cell what we have is that the nerve cells have dendrite now what is this dendrite these dendrites are the hair like structures that receives the impulses then it has a long store called the axon this axon transmits the nerve impulses and at the end you have the synapse now what is a synapse they transmit the nerve impulses from one neuron to another so the structure goes like this it has a nucleus hair like structure and a long stalk and at the end it has the synapse next is the muscle cell the function of the muscle cell is to contract and bring about the movement of different parts of the body and for that they are made up of the special fibers which helps them to contract and relax they contain special proteins that allow them to contract and relax they have loads of mitochondria which provides them energy to contract and they have special storage carbohydrates called glycogen which acts as a fuel for the muscles okay so for both of them you should know what is a function and what features do they have next is a sperm cell now if you look at this bum cell it looks like this at the top there's a head which has an acrosome and this acrosome contains hydrolytic enzyme which breaks the egg cell wall and penetrate inside the neck inside the egg to fuse with the egg new place the middle piece has mitochondria the mitochondria provides the energy to swim the nucleus contains the genetic information and the flagyl eyes the tail like structure which helps it to swim to large distances so I hope this function and you should be able to label this like what is a knack resume with its function okay the flagyl are with its function so you should know the different components of a cell along with their functions ok so now as we have finished a specialized animal cell in the same way we have the specialized plant sir now what are the specialized plant cell again these are those cells which have some extra features that allows them to perform special functions now again to write about these you should first know their function so root hair cells is a cell which act as an exchange surface and absorb water and now for the absorption of watering minerals it needs a large surface area so the root hairs are the extensions which provides a large surface area for the absorption of water in minerals then it has a large permanent vacuole which supports the cell and speeds the movement of water by osmosis at times it's not just the diffusion through which the water and minerals move the active transport also happens so for that there's a mitochondria inside the root hair cell which provides the energy for active transport it has a cell wall and it is just one cell thick so that these substances can easily diffuse and the diffusion pathway is reduced on the other hand there's a xylem cell what is the function of the xylem cell it transports watering minerals from roots to all parts of the plant now since it has to travel water to large distances it has to form a long continuous column the cells of the xylem czar dead so that they can form a long continuous column which can transport water to large distance and then inside you can see the lignin deposit the lignin deposit makes it waterproof and makes the xylem columns strong and strengthen the xylem vessel the phloem cell is again a transporting tissue but its function is to transport food from the leaf to all parts of the plant now the phloem has lost majority of the cell contents so that it can have more room for the food the cells at the periphery so it is in the form of the sieve tube and the cells which are at the end of the sieve tube they're broken to form a sieve plate so that the food can easily percolate okay and since the sieve tubes have lost majority of their cell contents they are supported by a special cell called the companion cell it supports the phloem cell and provides itself whatever they need specially they are rich in mitochondria which makes lot of energy for the sieve plates and sieve tubes so that they can transport food the last is the photosynthetic cell the function of the photosynthetic cell is to prepare food by photosynthesis so it has a large vacuole which helps in the movement of water by osmosis it is having loads of chloroplasts that helps it to trap light for photosynthesis also these cells lie flat onto the leaf surface near to that so that they can easily absorb water carbon dioxide for quick photosynthesis okay so I hope these special plants and animal cells are clear to you now the question comes in the cells we cannot see by the naked eye so we take the help of the microscopes so microscopes are the devices that use to see the cells which we cannot see by our naked eye and that to properties of the microscopes which are important and you should know the definition of them first is the magnification magnification is a property of the microscope to enlarge the object and resolution is the property of the microscope to distinguish between two closely placed object the magnification is calculated by the image size over an object size now this is an important question in the exam they can give you an image size and they can ask you to find the object size if the magnification is given or the image size and object size is given to you and asked you the magnification or to make it little complicated they can give you a cell and they can say that this diameter is 2 micrometer in reality calculate the magnification so in that case what you'll do you will take your ruler measure this actual length that will be the image size the object size they have already given you 2 micrometer make sure you make the unit same by the chart that I have just discussed I'll just put it again and then you find the magnification by doing the image size over the object size okay so the table that is given before helps you to convert the different units into a single unit and remember for the magnification both image size and object size should be of the same unit because magnification is the ratio okay so now there are two types of microscope first we had the light microscopes these are the microscope which you see in your school laboratory they are easy to handle small and compact does not require much expertise to handle and they just have either a mirror at the bottom or a bulb as it uses the beam of light to focus on the object whereas electron microscope it is not easy to handle it is begin on portable requires proper training it uses beam of electron to focus on the object okay now when we use a light microscope we cannot see the greater subcellular details because the light microscope has a very low resolving and the magnifying power the resolving power is 0.2 micrometer and magnifying power is just between thousand to 1500 whereas for electron microscope it has a greater resolving power around 0.5 nanometer and the magnifying power is around one hundred thousand times so it is the electron microscope that have enabled us to see a proper subcellular structures like mitochondria ribosomes and chloroplasts but for the light microscopes you can view the live samples and you do not require special preparation of the samples but for the electron microscopes the samples have to be done have to be dead and we require some special sample preparations like microscope we can just see the color images we can stain the sample and see the color images for our electron microscope it can form 2d and 3d but the images are black and white okay so I hope this difference between the light microscope and the electron microscope is crystal clear to you okay so make sure you can write the similarities and the differences between the two okay so now you should be able to know the difference between a plant cell on an animal cell the bacterial cell the like microscope and the electron microscope so now we have looked in what are the different structures found in the cell and what is what are the functions of each of the cell organelles now in order for the cell to survive the cell need materials the cell need oxygen the cell need glucose the cell needs proteins and signs and on the other hand the base products are also produced in the cell so the cell needs to get rid of them as well so there need to be the substances to move in and out of the cell which happens to the cell membrane but there are two processes that are involved in movement of substances in and out of the cell so we categorize these two processes in terms of active transport and the passive transport now in order to understand this active transfer and passive transport let's take an example of a hill so there's a hill and one boy is standing with the ball at the top of the hill and one boy is standing with the ball down now it is easier for the one at the top of the hill to send the ball down and it will not take much of the energy to send the ball down but on the other hand if you send the ball up you require more energy because it is going against the gravity the same thing happened in terms of transport whenever the particles move from low to a higher concentration which means the particles move against the concentration gradient it requires energy and this is known as active transport and when the particles move along the concentration gradient that is from a region of higher concentration to a region of lower concentration without the use of energy then that is known as passive transport now since the active transport requires energy and we know it is the mitochondria that is responsible for making energies for the cell so the cells which are involved in active transport have loads of mitochondria and in passive transport having numerous mitochondria is not a requirement and the passive transport is of two types diffusion and osmosis now let us see what is diffusion and what is osmosis now if you see this diagram here this was an empty container of water and a drop of ink which was purple in color was drop this ink started to spread out and it spread it out evenly until the particles of the ink are evenly distributed in the water you can see this with this example there are more particles onto the left side as compared to the right side so the particles with time from the left side move towards the right side until the concentration of the particles is equal on both side this phenomenon is diffusion now if it comes in the exam how will you define diffusion you will say it is the net movement of particles from an area of a higher concentration to an area of lower concentration it is a passive process so it does not require energy as the particle moves along the concentration gradient now what are the factors that affects diffusion now the diffusion is dependent on four important factors one is the surface area second is the concentration gradient third is the diffusion distance and fourth is a temperature now greater the surface area greater is the rate of diffusion of the particle because if the surface area is more the particle will gets more room for movement so all the exchange surfaces have a greater surface area like the root cells has roaches and intestine has realized the greater the concentration gradient in the two regions greater is a rate of diffusion so all the exchange surfaces there if a they've maintained the steepest concentration gradient how the root cells are close to the xylem and rely has rich blood supply that maintains the concentration gradient now diffusion distance has to be smaller for the diffusion to takes place because the particles they travel less the distance they will diffuse quickly so all the exchange surfaces maintain a smaller diffusion distance by being one cell thick so if you see any of the exchange surface it will be one cell thick and last as the temperature greater the temperature greater is the rate of diffusion as the particle will get more kinetic energy for movement so to summarize I can say that rate of diffusion is surface area times the concentration gradient divided by the diffusion distance and you need to remember that because if any questions on adaptation of diffusion fanzine you need to talk about all these four factors how that particular surface is maintaining a higher surface area greater concentration gradient smaller diffusion distance and temperature now the diffusion in animals are two examples for diffusion and animals in lungs or the alveoli there's a diffusion of gases that takes place and in small intestine diffusion of digested food takes place if you see this structure of the alveoli the lungs have millions of alveoli which increases the surface area for the shorter diffusion distance they are one cell take and for maintaining the concentration gradient they have rich blood supply on the other hand this small intestine the wall is folded to form finger-like projections called the villi we lie on one cell take and they have rich blood supply so if this question comes in the exam what are the adaptational all these three factors of the largest surface you raise maintain are the diffusion distance is maintained and how the concentration gradient is maintained now another example for diffusion in plants is diffusion of gases through the stomata and the fusions of water and minerals through this stem so first to Mata it has a greater surface area because it has tiny post called stomata but thin diffusion distance they are one cell thing and for sleep concentration gradient photosynthetic cells are close to stomata for the root hair cells the roots are project to form the roots hair cells root era one South's egg and to maintain the concentration gradient xylem is located close to the root hair cells okay so I hope the examples of diffusion in plants and animals along with the adaptation they have for maximum diffusion is clear to you now let us look at another special case of diffusion called osmosis now why are masses is a special case because there are two special things in osmosis first it is the diffusion of only water molecules diffusion can be diffusion of any substance but as masses as the diffusion of just water molecule and second it is a semi permeable membrane or partially permeable membrane is required now what is a semi permeable membrane the membrane that allows only specific molecules to pass through like water now if you see this diagram here where there is more water the water is more in the left because there is no solute on to the right there are salt molecules so it has less water so water from the guy whose solution dilute means has more water passes through this concentrated solution to this semi permeable membrane until the water concentration is equal in both cases and this is known as osmosis so as masses is the net movement of water particles from the region of high concentration of water particles to region of low concentration of water particle across a semipermeable membrane or you can say it's the movement of water from a dilute solution to a concentrated through a semipermeable membrane so I hope this definition of us masters in this concept that it is a movement just from water power molecules to use a semipermeable membrane and it's a movement of water from a dilute to a concentrated solution is clear to you always remember don't write it is a movement of substance from high concentration to low concentration that's the wrong definition it is high concentration of water to a low concentration of water is the correct one now let's see what happens how as masses and fans takes place now there are generally three kinds of solution hypertonic hypertonic isotonic hyper means more more solute so the hypertonic is that solution which has more solute so less concentration of water hypertonic is the solution that has less solute so more concentration of water and isotonic is a solution which has same concentration of water in and out so if we place a plant cell in a hypertonic solution what happens the Alta solution has less water so the water from the cell will move out of the plant cell by osmosis so the plant cell will shrink and it will recede or move away from the cell wall and this is known as plasmolysis so when a cell is placed in a hypertonic solution it shrinks and this condition and the plant cell is plasmolysis on the other hand when you place it in a hypertonic that is more concentration of water the water will move into the plant style by osmosis then the plant cell will increase in size become swollen as it becomes swollen it will give a pressure to the cell wall and the cell membrane that pressure is known as a turgid pressure or the thurible pressure and that makes the plant cell in its proper shape on the other hand if we place it in an isotonic solution it will have the same concentration of water outside and inside so there's no net when the water as a result no pressure will build up and the cell will be soft so in the plant cell there are three terms surge it plasma lies and flat fit and you need to remember these terms next is in plants if you place it in an hypertonic solution that is more concentration of solute the cell will lose water by osmosis and shrink in size if you place an isotonic solution there's no net movement so the cell remains intact and in an hypertonic solution the cell will gain Volta sidled swell and it can eventually burst as well good time now the next transport is the active transport active transport as you remember we did uphill and downhill so active transport is uphill that is movement of substances from low concentration to high concentration that is against the concentration gradient with the use of energy it is dependent on respiration as it requires energy so the cell involved in active transport have lots of mitochondria in plants where active transport takes place it takes place in the roots where motor and minerals need to be absorbed against the concentration gradient so that maximum water and minerals can enter the plant root and an animal at times the digestive food even after proper diffusion need to be absorbed more so that the maximum absorption takes place so their active transport chip plays a role and in some of the marine organism that has a lot of concentration of salts developing the body so they expel that excess salt by the sole glands which works by active transfer okay so I hope the movement of substances in and out of the cell is clear to you now we need to do the next thing that we know the cell perform its function but the cell has to divide why the cell needs to divide for reproduction growth and prepare now how does the cell cycle takes place this cell cycle is divided into three stages first is the preparation phase which is the interphase stage it is the longest phase of the cell cycle in which the cell grows in size and prepares the cell by making all the proteins and the enzyme needed for cell division and the very important step that takes place in the interphase stages of replication of DNA where the DNA duplicates its content after this preparation of the interface stage is done then comes the mitosis stage mitosis is a division of the nucleus in which the parent cell splits into two daughter nuclei as the parent cell so the daughter cells are genetically identical and next to cytokinesis it is a division of the cytoplasm which takes place after the division of the nucleus now what is mitosis it is a type of cell division in which a parent nuclei divide to form two daughter nuclei with exactly the same number of chromosome as that of the parent nuclei the daughter cell videos are genetically identical to the parent and we can hold them clones this division is important for growth regeneration and repair and mitosis is also important in asexual reproduction now how the stages of mitosis takes place has a diagrammatic representation of it we started with although there are 46 chromosomes 23 pairs but for diagram we are using starting with 2 chromosomes so these two chromosomes first duplicated once they duplicated the lies at the center through these spindle fibres the spindle fiber shrinks and breaks them from the middle so that each and now has two chromosomes copy and then the nucleus divides so we get two daughter nuclei with exactly the same number of chromosome as the parent nuclei ok so I hope this mitosis is clear to you you should know what are the stages of the cell cycle how the cell divides what is importance of my to says and what is the significance of mitosis ok now let us see how the development of a human cell takes place now let us look at how the process of self specialization takes place now let me first explain you what is the entire lifecycle of a living organism now we have a male parent and a female parent now both male parent and female parents have 23 pairs of chromosome this what you need to remember we have 46 chromosomes 23 pair from which 23 has come from our mother and 22 from our father now males LD undergo another division we just saw mitosis there's another division called new cells which produce half the number of chromosomes and is required to make the gametes so the male pattern make a sperm or a male gamete and a female parent makes ovum or a female gamete and both has 23 chromosomes during fertilization they both fuse to form a cycle and this cycle now has 46 chromosomes so the 46 or 23 pairs numbers is restored now this icon divides into two four a six eight and many cell types and forms an embryo now at this stage the entire cell is unspecialized it has no function we do not know which part of this cell will form the digestive system which part of the cell will form the circulatory system after that the process of cell differentiation begins now this embryo which cells have not yet specialized are stem cells so stem cells are the undifferentiated mass of cell which can differentiate into any cell type now after this what happens is the process of cell specialization where the cell becomes specialized to perform specific function so some part of the cell will get specialized to form the circulatory system some will specialized to form digestive system and will give rise to a whole new organism so in plant cell the majority of the plant cell are the stores of stem cells the root meristem shoot meritum are the parts of actively growing part of the cell which contains the stem cells we can take that and make a new plant the plant can be grown easily because majority of the parts are not differentiated and the ones which are differentiated their differentiation is not permanent so they can be reversed okay now in animals majority of the cells are differentiated at a very early stage in a plant they get differentiated at a very late stage so as in plants they are differentiated at a very early stage they are already specialized to form a nerve cell or a muscle cell now adult cells replaced the old and worn-out cells in humans but they also have a limited regeneration and specialized power and as majority of the differentiation is permanent the cloning of the animals is difficult so this is what is happens in an animal differentiation and this is what are the plaintiff in CA ssin okay so now what are stem cells so stem cells are the undifferentiated mass of cells that can differentiate into any cell type the sources of the stem cells are embryo leftover remains of the embryo unbeli Colcord these are the sources of embryonic stem cells and bone marrow is the source of adult stem cells and what is the possible promises of those stem cells a lot of problems in which the transplantation gets failed due to the rejection throughout the recipient from their donor because the cell recognize it as a foreign and the immune system tries to kill it but if the stem cells of the person body are used to generate the organ then the chances of rejection can be solved second a lot of neurogenetics on rating disorder in which the part of the nerve cells get damaged if the person stem cells can recreate those nerve cells and the neurodegenerative disease can be treated the disease like blindness can be treated it can be a cure of diabetes if the beta cells of the pancreas get regenerated it can help in a therapeutic cloning in a therapeutic cloning we take the adult stem cells make it to make the embryonic stem cells and then embryonic stem cells are specialized to make them desired Oregon and it can also solve the organ damage problem so stem cells is a very good promise very good potential medicine revolution for future however there are a lot of issues against the stem cell as the cells of the stem cells are rapidly dividing if we introduce the stem cell into new organism it can lead to cancer the stem cells can be contaminated and can cause unwanted diseases to the patient the research in stem cell is still slow and expensive the research happens on aborted embryos which is considered as a potential source of life and many religions have ethical concerns again said and the knowledge of cell specialization was jeans get switched and on/off on differentiation is still ok so I hope we have covered this topic in a much detail and I have tried to cover the maximum of your specification now it's the time to test yourself by seeing if you know these key times so what I cells mitochondria nucleus cytoplasm ribosome prokaryotic eukaryotic cell cell walls cell membrane vacuole microscopes resolution magnification xylem phloem diffusion osmosis plasmolysis turgid flats in mitosis differentiation stem-cell therapeutic cloning if you are still not clear with these terms I would recommend you to go back watch the videos and then try over these key terms and now you can pause the videos and have a go on trying these key terms ok so I hope now you have written these answers on what is the meaning of these few times now let us look at your answers what ourselves cell is a basic structural and functional unit of the living organism mitochondria is the organelle which is the site of aerobic respiration nucleus is the organelles which controls the activities of the shell cytoplasm is a jelly-like fluid which turns the cell and contain enzymes for chemical reaction ribosomes are the cell organelles for the site of protein synthesis prokaryotic cells are the primitive cell without nucleus or membrane bound organelles eukaryotic cell related Ron cell tied with nucleus and membrane-bound organelles cell walls is the outer layer of the plant cell which provides shape and support to the plant cell membrane is the outer layer that controls what goes in and out of the cell vacuole is an organ present in the plant cell which has cell sap and makes the cell surge a microscope is a device that is used to see the objects which are not visible by the naked eye resolution is the ability to distinguish between two closely placed object magnification is the ability to enlarge an object xylem is a transporting tissue that transport water in mineral so in transport few diffusion movement of substances from high concentration to lower concentration as masses is a movement of water molecule from a region of high concentration of water low concentration across a semipermeable membrane plasmolysis is a shrinking of plant cell when placed in a hypertonic solution dodge it is a fully swollen cell which has gained water by Ausmus says Placid is a sub cell did you know net movement of water mitosis is cell division that produces identical daughter cell differentiation is cell specialization stem cell is an undifferentiated mass of cell that specialized to any cell type and therapeutic cloning is using adult cell to produce embryonic stem cells and so I hope now you are welcome with this topic now what you need to do next is check the specification make sure the specification is cleared to you and then you need to do the exam question on this topic if there's still anything that you do not understand leave a comment below and we reply you as soon as possible or you can come to a website where we have set our 24/7 chat support till your exam you can come anytime ask any questions and you can get instant subscribe if if you like this video then do subscribe to our Channel and do not forget you like comment and share this video if there's any specific topic you want me to make the next video on then also do leave a comment below and I'll make sure I put that up before your exam okay so I'll see you next in the next video of the next section till then happy revising