someone has very rightly said that Time and Tide waits for none that means once the time is gone it is never gonna return back that means you should start preparing for your neat examination from today itself those students who are willing to appear in neat or J examination next year should start a preparation from today onwards don't wait for anybody just put in your 100 efforts start hard working do not wait okay still a lot of time is there we can start a preparation no there is no time there is actually the clock has started ticking and now it's you who have to decide that whether you have to go with the time or against the time if students you go along with the time surely you are going to succeed but if you are still preparing if you're still thinking to waste the time to still think upon that okay now what to do what are the other aspects and so on then it's all upon you for those students who are absolutely willing to become doctor next year for them we have launched this batch Excellence batch Excellence itself means 100 Excellence means there is no scope of any error you have to be the best so this that is specifically for those students who think that they are the best and yes they can crack neat examination in their next attempt so for all those students who are absolutely willing to put in their 100 effort to put in their hard work to achieve your dream to crack neat Examination for such student this batch Excellence has been launched and I really hope that whosoever is watching me whosoever is listening me each and every student is excellent in themselves yes or no we all are excellent It's just that somebody has to punch you somebody has to guide you that yes you have that capability you have that capacity it's just you have to push yourself and so to push all of you I'm over here I'll be taking your botany in excellence badge for your neat preparation right I don't think you all must be uh not aware about me so yes I have already taken your Victory batch my name is ayushi Agarwal and once again I welcome you all to this amazing platform of physics Wala with this Excellence badge for your need J preparation okay so I'll be taking your botany and this is going to help you crack your neat examination in this batch we are going to start the syllabus of class 12th so the first chapter in class 12th which we are going to start today is reproduction in organisms correct but this chapter is 50 with botany 50 with zoology so the botany portion we are going to start and in Zoology also you will start with the same chapter the other half of the chapter correct so yes we are going to start with this chapter but before we start this chapter we all have to take an oath the oath says that we are whatever we are going to do we are going to do in favor of us in favor of us means we are going to give our hundred percent we all are going to put in our best efforts hard work to achieve our dreams not even single day we are going to cheat on our studies because single day cheat means you have just broken the streak you know we all are using the Instagrams and Snapchats you know you have to send the streaks on daily basis to your friends on Snapchat so once you don't send that streak is broken similarly if you don't study for even one day then you see your streak will be broken and somewhere you'll start lacking from the other students who are still in the league so if you really don't want to break the streak so you have to take a note that yes we are going to put in our 100 effort we are going to work hard to achieve our dreams with Excellence batch so are you all excited then yes thumbs up to all my students and without further wasting time let's start the first chapter which is reproduction in organisms beta today we are going to cover reproduction chapter the first chapter till types of reproduction okay and then we are going to further continue in this chapter now the name of the chapter says reproduction in organism so let's first try to understand the term reproduction itself now you all know organisms who have came on Earth they are going to die once yes the Earth in mythology it is said that there were two people who came on Earth Adam and Eve yes and then the whole generation started so what is actually that process which is responsible for continuing the species on Earth what actually that couple Adam and Eve did to maintain the continuity of life on Earth see Adam and Eve were sent by the God but obviously they died yes they were they're not they were not Immortals they died but still the race of humans is still continued that means they must have shown some biological phenomena in order to maintain the continuity of life on Earth and that biological phenomena is actually reproduction reproduction can be defined as a biological phenomena by which living organism produce new young ones of Their Own Kind so what is reproduction how can you define reproduction see it's a biological phenomena where parents give birth to young ones of their own kind of Their Own Kind means dog will give birth to dog cat will give birth to cat it's not like cat is giving birth to dog or vice versa so what is reproduction once again it is a biological phenomena by which living organisms give birth to young ones of their own kind in order to maintain the continuity of generation on Earth in order to maintain the continuity of species on Earth can we imagine our life without this biological process no why because if reproduction would have not been there obviously you and me would have not been there on Earth Adam and Eve would have came died went back and Earth would be left with no humans if reproduction would have not existed so yes it is a very very important biological process for maintaining the continuity of life on Earth correct now reproduction basically beta it is a carrot characteristic property if you have heard if you have studied chapter Living World in class 11th then there are two types of features characteristic features and defining features characteristic features are those which are either exhibited by both living and non-living objects or only living organisms but with few exceptions so this reproduction beta basically it is a characteristic feature foreign it is a characteristic feature because all living organisms cannot reproduce there are certain Exceptions there are certain living organisms who cannot reproduce like worker bees mules there are some sterile couples who cannot produce their own young ones so because of this reason this reproduction is a characteristic features I'm writing over here that what do you mean by characteristic feature please if you're listening if you are going through the entire lecture make sure that you are making your notes along with me better let me tell you one thing which is very very important if you really want to study with this Excellence batch then don't consider don't take this batch very leniently don't take the classes very leniently don't indulge yourself into any kind of nuisance activities I hope you are getting my point so if you really want to study with this Excellence batch then on daily basis first of all you should be active on the classes second while the teacher is teaching you should also try to make your own notes sit with the pen and a notebook as and when I am telling you anything or whatever if I'm writing on the board then you should also try to write just consider that you are sitting in a proper class and your teacher is teaching you imagine if there would have been a class of 50 students and I would have been teaching in that class then obviously whatever I would have been writing on the board you would have also been writing in your notebook correct so just consider that yes you are sitting in a class I am there physically maybe I'm not there actually but you have to imagine that yes ma'am is there she is teaching us we have to make our notes but Cho if you follow this thing for the entire year I guarantee you nobody is going to face any trouble right so if you really want to avoid any troubles and if you really want to study well and achieve your goals and dreams so please listen to me make note of this that whenever I am going through the class I'll sit with the pen and a notebook I'm not going to lie down on the bed have my phone on my hand with speakers on and all the chaos going on going around in the home no not like this study seriously seriousness is very very important apart from putting in your hard work your efforts seriousness is also better very very important so please become serious give your show your seriousness in your studies okay I hope you all are very good student you are going to listen to me and yes you are also going to follow my instructions so with this let's come back to the topic I was telling you that reproduction is a characteristic property because all living organisms do not reproduce cannot produce their new Young Ones there are certain exceptions like for example mules The Offspring of horse and Donkey mules they are basically infertile second worker bees third some sterile couples this point you also study in class 11th the first chapter itself living world I hope you all can correlate from there very good moving ahead there can be two types of reproduction there are two ways of producing new young ones one is asexual second is sexual reproduction so now let's try to understand what do you mean by asexual reproduction and sexual reproduction with the help of this chart here I am going to explain you asexual and sexual by writing the points of differences number one point okay yes so number one point to differentiate between asexual and sexual is asexual reproduction means the reproduction in which only one parent is involved so you can write that asexual reproduction are [Music] uniparental uni parental means only one parent is involved however if I talk about sexual reproduction students then sexual in sexual reproduction it is usually by parental when male body is required and one female body is required male body will produce male gametes female body will produce female gametes however in those organisms whose in whose body both male and female gametes can be produced then yes one parent can also show sexual reproduction like for example bisexual flowers china Rose there is one china Rose in that one china Rose and rosham is also there to produce male gamete and gynoshum is also there to produce female gamete so one parent both the gametes are produced in the same parent in that case sexual reproduction can be mono or uniparent however in general if we see if I talk about human beings then there is Father producing male gamete there is Mother a different body producing female gamete so for sexual reproduction you can write it can be both by parental and uni parental usually it is by parental but sometimes bodies who can produce both the types of gametes male and female can also show sexual reproduction correct so what are you going to write may be by parental which is generally or sometimes uni parental as well uni parental in those organisms who are bisexual means who are producing both male and female gamete in the same body clear to everybody okay second point of difference beta in asexual reproduction gamete formation may or may not take place however even after if gametes are produced they are not going to fuse to form zygote gamete formation may take place but their Fusion transfer will never take place there is no even such as zygote formation during asexual reproduction however in sexual reproduction gamete formation their Fusion to form zygote is very very important so second point of difference is for asexual you will write gamete formation may or may not take place May or may not take place not necessary however Fusion can never happen however gamete Fusion will not occur clear but in sexual reproduction my dear students both gamete formation and fusion is a must process both gamete formation and fusion is must phenomena clear to everyone the second Point very good now moving towards the third point if I talk about asexual reproduction beta then organisms undergoing asexual reproduction the offsprings produced they are exactly same as that of parent both genetically as well as morphologically that means you won't be able to identify that okay which is the parent which is The Offspring because they're going to be 100 percent same such offsprings are known as clones but if I talk about sexual reproduction but Cho we all are the product of sexual reproduction we are similar to our parents like we say that my nose is similar to my mother my ears are similar to my father my mouth is similar to my father and so on but do we say that we are exactly clones of our parents no in sexual reproduction the offsprings are similar to parents but not identical not clones correct so what is the third point of difference here you will write of Springs are identical to parents correct both genetically and morphologically so there is a term which is used called clones you can say that offsprings are clones of their parent in case of asexual reproduction however if I have to write in sexual reproduction then what am I going gonna write offsprings are similar to parents but not identical correct we are not clones are some of the features may be similar to our parents but not all the features right moving towards the next point of difference to between asexual and sexual asexual better reproduction is a fast process simple process right not a complex phenomena simply there will be a parent organism who is going to divide into New Daughter organisms without any much preparation simple preparations will be done in the parent body and then on the onset of favorable condition parent is going to divide to produce offsprings so asexual reproduction is very less time taking simple phenomena fast phenomena no much preparations are done in the parent cell before division however if I talk about sexual reproduction then sexual reproduction is a slow complex elaborate mechanism lot of preparation has to be done before sexual reproduction you know in humans nine months it takes nine months to produce a baby and even before that the process start first there has to be gamma information then gamete transfer Fusion zygote and then zygote develops into a baby such a long process so sexual reproduction is a simple oh sorry it's a complex slow and elaborate phenomena yes or no which takes a lot of time on the other hand if I talk about asexual then it is a simple fast and less time consuming phenomena correct I hope you all have understood this point as well if I talk about specifically asexual reproduction then asexual reproduction is simply responsible for increasing the number of organism for simply increasing the population of organism without any change without any variations all the organisms are going to appear exactly same there will be no difference between the parent and Offspring but in case of sexual reproduction offsprings are produced due to variations you know in parents in mother body and father body first gametes are produced first haploid cells called gametes are produced after meiosis so due to meiosis what happens there is Introduction of during meiosis you know crossing over takes place there is exchange of genetic material between the homologous chromosome because of which variations are introduced so beta whatever gametes are produced inside the male body and female body are the variable products gametes are variable products they are not thus exactly same cell as other cells gametes both sperm and egg if I have to mention exactly the name sperm and egg they are not same as other cells of the body they are different why because they're produced after meiosis they are the product of variation they are the product after crossing over correct now such variable products from the parent body if diffuse then obviously the result that is zygote will be a variable product of both the gametes of both the parent now when the zygote develops into a new Offspring then Offspring will carry features similar to mother and father but not identical features correct as The Offspring is produced from the gametes which are variable which are not exactly the same as that of the other parent cell gametes themselves are different now when different cells diffuse from the parent body then obviously a different organism is going to be produced now organisms The Offspring which are produced they are variable so this is known as variations every time sexual reproduction takes place every time new generation is produced variations are introduced in every round of reproduction grandparents great grandparents produce grandparents slightly different grandparents produced parents more different parents produced you more different now you are going to produce the Next Generation more difference so so many steps of variation occurring in the same family now if your son or daughter is again going to reproduce and if this is going to continue for Generations then all the variations are getting accumulated and a time will come where there's going to be Evolution so you can say that sexual reproduction is one of the important reason that leads to Evolution why because during sexual reproduction variations occur the offsprings which are produced are not identical to the parent they're slightly different again different again different so these differences they accumulate in every generation and a time will come a completely different organism will be produced as compared to their ancestors you know we say that monkeys are are our ancestors but are you similar to that of monkey are you the cop do you really feel that you are the ancestor that your monkeys are the ancestors no hardly any similarity is left between you and monkey but still they are ancestors why how can we say that monkeys are our ancestors and why we don't appear to be similar as that of monkey because number of sexual reproduction has taken place number of variations have accumulated that has resulted in evolution now we are evolved form of our ancestors we are evolved form of our ancestors imagine if no sexual reproduction would have existed we would have been exactly same as that of monkey even today so thanks to the sexual reproduction that Evolution took place and we are evolved form of monkeys chimpanzees and gorillas we are not exactly their copies but yes some of our features like a brain capacity Etc still somewhat similar but not identical correct have you all understood this point very good so now let's write in asexual reproduction no variations hence asexual reproduction does not contribute in evolving organisms hence asexual reproduction do not help in evolution it is not responsible for evolving organisms but sexual reproduction variations plus evolution is one of the important event that takes place due to this phenomena so you can simply write that variations plus evolution are the important event of sexual reproduction important event of foreign sexual reproduction I hope I am clear in this process in this Point as well so these are the some differences between asexual and sexual reproduction details of SEC asexual that means how asexual reproduction takes place by binary fission budding sporulation Etc all that we are going to cover and events of sexual reproduction are also going to be covered in this chapter so basically this chapter you are going to study the details of asexual types of asexual and details of sexual reproduction both we are going to study but before we switch into that I have already explained you the basic differences the basic points of asexual and sexual reproduction I hope you all have understood this and written it as well now the next terminology in front on your screen is lifespan now what do you mean by lifespan lifespan but show can be simply defined as the time period that ranges from birth to Natural death you know any organism will be sent on this Earth then that that organism is going to live for certain duration and a time will come that fellow is going to die and go back from where from wherever it came so that duration for which that organism was on Earth is called as lifespan lifespan is highly variable it does not depends upon the size or complexity of any organism lifespan has no relationship with the size it doesn't means that if organism is very huge is going to live long or if organism is very tiny is going to live for lesser time no no size no complexity it's not that if my DNA is very good strong I have more number of chromosomes then I am going to live for long and if any organism who has less amount of DNA less number of chromosome is going to live for lesser time no this lifespan is highly variable and does not depends upon the size and complexity of an organism this lifespan is a variable feature correct for example I'll explain this point with the help of an example you know Crow and parrot both are aves both are birds almost their size is also similar if you see Crow is also this much parrot is also this much this much they both are aves so almost complexity within the organism is also going to be similar but still Crow only lives for 15 years whereas parrot can expand its lifespan to up to 140 years can you see the difference no correlation of lifespan with the size or its complexity one more example I am going to quote to make you understand second point is that you must have seen people tree as well as mango tree both are both are perennial trees thick both are your plants but still mango can maximally live for 250 years whereas people is expected to live for more than 2 000 to 2500 years and you can write for mango 100 to 250 years so can you see the variation in their lifespan that means lifespan does not depends upon the size or complexity of any organism so these are the four lifespan which you have to remember apart from this some more lifespan I am writing please remember them as well questions can be asked from these lifespan as well wheat the maximum lifespan of wheat it's a monocarpic plant is three to four months you know you plant seeds of wheat wheat they flour and then you chop them so maximally wheat can live for three to four months coming next is rose plant four to five years right oh yeah yeah foreign lives for two weeks next I will write uh over here butterfly your beautiful butterflies they maximally live for again one to two weeks right banana tree banana tree has maximum lifespan of 25 years so this also you can learn foreign the maximum lifespan can extend up to 25 years so these are the few lifespans which you can remember if you are more given in ncrt you can also consider them sometimes you don't know neat that what kind of question they are asking they can also ask questions on these lifespan so you should be knowing it as it is given in your ncrt book that's why I have mentioned it over here as well now moving ahead see okay I need to add one page before I explain you some more points but now we say that lifespan is a fixed duration that ranges from birth to death that means when I say this statement I mean to say that death is inevitable every organism who has came on Earth has specific lifespan will complete the lifespan and will go back that means death is inevitable this is the harsh reality of life that if you are given with it it will be taken as well correct so we can say that none of us are Immortals all living organisms are Mortals we have to die one day so what I'm going to write next point all living organisms are mortal mortal means one who has to die one who is not permanent except single-celled organism single-celled organisms the organisms who are unicellular whose body is only made up of one cell like for example your bacterias and members of Kingdom Protista like amoeba paramecium these single-celled organisms they are considered as Immortals why why are they considered as Immortal because in single-celled organism students growth and reproduction are mutually inclusive phenomena correct suppose this is a parent cell this is a unicellular organism parent cell if it wants to reproduce the only method is dividing correct this single-celled organism will divide the parent will divide and it will convert itself into two new daughters now in this what you have seen the parent has converted itself into two new organisms so will you say that parent has died no there is no parent once division took place there is no parent left parent has just given birth to produce too new offsprings so will you say that this parent has died while giving birth or will you say that this parent has lost its identity has undergone division to produce new Offspring I hope second statement is better that the parent loses its identity it divides to produce new offsprings that means you cannot say that the parent is dying it is simply converting itself into new organism now later these daughter organisms will grow they will further divide to again produce new organisms so like this single-celled organisms better they don't die they simply reproduce they simply divide to produce new organisms which further divide and this process keeps on happening so here you can see reproduction is taking place parallely growth is also taking place how growth initially there was one cell now two cells then four cell so number of cell is also increasing along with reproduction growth and reproduction that is why it is said that in single celled organism they are one and the same process they are mutually inclusive phenomena when single-celled organism they reproduce they are actually also showing growth so you cannot say that this parent has died it has simply converted itself into two new daughters two new daughters means two new cell so growth has also taken place getting my point understood Chalo so let's write this point over here that these are Immortals because parent divides means reproduces to produce new organism so here you can say that parent is simply losing its identity to produce new Offspring you cannot say that parent died in producing new organism right so there is no death taking place in single-celled organism while reproduction correct now one more Point note point you have to write in single celled organisms beta growth and reproduction are mutually inclusive phenomena I hope I I am very clear in this point and you all are not going to forget this point promise me this is going to come in next year neet examination so just make sure that you will remember this line very well okay so this is all about lifespan now when I'm discussing lifespan that means I need to also discuss phases in your lifespan that when you are living your life then how many phases your life exhibits so you can simply say that life goes through three phases in its span pre-reproductive also called as juvenile or vegetative phase correct then reproductive and last comes post reproductive or sunny-cent phase yes or no whenever any living organism who is capable of showing sexual reproduction is exhibiting life is completing its life on Earth has to pass through these three phases right now you must be in your vegetative or pre-reproductive phase you'll grow up you'll enter into reproductive phase that means you're going to you're going to reproduce you are going to produce a new Offspring then slightly your body is going to deteriorate and from reproductive you will enter into aging your body will start showing aging you will become old that is called as post reproductive and then comes the death so first like let's talk about the pre-reproductive also known as juvenile also known as vegetative phase in animals we use the term juvenile for pre-reproductive for plants we use vegetative for pre-reproductive so pre-reproductive means phase of life in which an organism is simply preparing an organism is preparing to reproduce but actually not reproducing when when you when you were a kid your body was getting your gonads were getting ready to produce gametes but at that time you could not reproduce once you attain your puberty once your gamete formation starts then only you can reproduce but before that you are in your pre-reproductive in your juvenile phase so when the phase of life in which an organism is preparing for reproduction but cannot reproduce during this beta during juvenile phase body is showing maximum growth correct why because anabolic reactions the rate of anabolic reactions are greater than rate of catabolic reactions more growth reactions are taking place rather than degrowth reactions so here you will write second point anabolic reactions are more as compared to catabolic reactions so overall body is growing as a result body grows then we become adult argonads are ready to produce gametes so that means we have escaped pre-reproductive and we have entered into reproductive phase so when now body is ready to reproduce ready to produce new offspring correct now since we are studying botany so I'll be teaching you reproduction in plants in Plants beta on the basis of the reproductive capacity we are having two categories monocarpic plant and polycarpic plants monocarpic and polycarpic beta mono means once so those plants which are capable of reproducing which are capable of producing flowers you know in Plants reproduction means producing floods flowers are the babies of the plants right so those plants which flowers only once in their lifetime those are known as monocarpic those plants who can only reproduce once are monocarpic like for example all annuals your wheat rice Maize barley all biennials right those plants whose lifespan is for two seasons are biennials so all annuals all biennials like cabbage carrot they are biennials they all are monocarpic along with few perennials like bamboo I'll tell you I'll write it please listen to me carefully so what are monocarpic plants uh so what are monocarpic plants plants which flowers which reproduces reproduces means which flowers only once in their lifespan I hope you all are able to understand throughout their lifespan you can add it I don't have that much of space so just you can add the point over here okay for example all annuals biennials and few perennials [Music] [Music] annuals means like wheat rice vinyls means like cabbage carrot and few perennial perennial meals those plants who can live for more than two years but they flower only once hence they are perennial but categorized under monocarpic so perineal like for example bamboo beta lifespan of bamboo can range from 50 to 100 years however it flowers only once bamboo will flower and then will die so being perennial being such a long lifespan still it is monocarpic it reproduce only once on the other hand are another group called polycarpicker poly means beta many so plants which reproduce again and again plants which can flower again and again are polycarpic for example majority of the perennials majority of perennials foreign majority of perennials are polycarpic like your mango apple banana so many once you plant mango tree for next 50 years it is going to give you mango you don't need to again wait okay this year again I will plant new mango seeds to to get new mangoes no mango tree is a perennial polycarpic plant why because it is going to live for long and it is going to flower it is going to reproduce also again and again so what are two types of plants on the basis of their capacity of reproduction polycarpic monocarpic clear to each and where each and every one of you very good now once flowering is done once imagined reproduction is done even whether it is polycarpic or monocarpic reproduction process is done correct now one time after 50 or 100 years mango tree will also deteriorate now even after 100 years mango tree is not that if you planted mango tree then for 100 years after 200 years also it is going to stay like that no you have seen mango tree can live for near about 100 to 250 years only that means a time will come when such plants will escape reproductive phase and will enter into post reproductive or sunny-cent phase this is actually aging this is that phase in which the organism is not able to any cannot reproduce further so when organism is not able to reproduce further that means that organism is showing signs of aging is showing signs of senescence the body is deteriorating because the rate of catabolic reactions has exceeded the rate of anabolic reaction what you have seen in pre-reproductive the anabolic reactions were more than catabolic so overall body was growing but just the opposite happens during post-reproductive or senescent phase what happens over here anabolic reactions the rate of anabolic reactions are going to begin are going to become lesser than catabolic reactions or you can say that rate of catabolic reactions are going to increase because of which overall body deteriorates and shows signs of aging shows people signs of aging that ultimately leads to the death of the organism so after body enters into post-reproductive it is the it is going to lead to the final stage that is death so after this comes the death I hope I am clear with all the points whatever I have taught you today's class has been very very easy it's just the beginning of class 12th just the first chapter reproduction of organism a very simple and easy going chapter and we are going to take three more lectures to complete this I hope whatever I have told you today you all have understood it well if yes then please do not forget to mention your experience of the class in the comment section and yes that is very very important so before we end the class let's discuss the questions the question number one is on lifespan lifespan is period from birth to death is the first statement correct yes second it does not depends upon the complexity of organism correct see statement does not depends upon the size of organism correct all the three above statements are right so the answer of the question will become D I hope you have understood this question if yes then I will give the second question as homework let me see that how many of you listen to me carefully how many of you understood this first lecture if you're able to solve this question that means you are listening to me carefully you are paying attention to your teacher so please take it this as homework and how will you answer you will answer in the comment section you know so with this simple yeah okay sorry I have one more question I thought only two questions are there so one more question is there again this is a homework what is sexual reproduction so sexual reproduction is four options are given please try to answer and answer in the comment section as well so that I also come to know that how many of you are really taking interest in studies so with this simple explanation of lecture 1 reproduction in organism I take your Leaf what should I say yes so yes bye bye to everyone take care see you in the next lecture