 Hello everyone. Am I what I will do you? Am I what I will do you? Yes, sir. Yes. We have started, I think genetics. Yes, everyone. Let's start with genetics. Have we done this thing? This thing is done now? Everyone? Yes. Let's see. Mendel has discussed these seven pair of contrasting characters that were there. Yes or no? No issues. They were contrasting. Okay. One is dominant and one is recessive. We are going to discuss what is dominant and what is recessive later on. Okay. Yes. There are a few. You all can see the comparison was the character is seed shape, dominant word, round red, recessive trait. If you will talk about seed color which is yellow and green, yellow is the dominant one. Green is a recessive trait. Getting my point. If you will talk about pod color pod color actually green is dominant yellow is recessive it suppose it you all can see over here flower color violet, white is recessive, flower position is there so axial flower and terminal flower over here. Terminal is one which is at the end so it is flower position. Stem is tall and dwarf. Tall is dominant and dwarf is recessive. These are the characters that were considered by Mendel. Yes or no? We have done this thing. No. Some definitions are there. One definition is of unit factor. Actually do you people know the term gene was not given by that time. Gene was not given at that time. Mendel has used the term unit factor. Agreed? Everyone. I am unable to you all know. Yes. Mendel has given the term unit factor and he is told some unit factor is there which is the unit of inheritance and which controls a trait singly in case of haploid and along with another factor of similar type in case of diploid organism. You people understand haploid and diploid no? Yes sir. We have applied a set of chromosomes and deployed having two sets of chromosomes. Yes or no? Agreed everyone? Applied having only one set of chromosomes and deployed having two sets of chromosomes. They are known as homologous pair. Yes or no? Tell me dear. Now gene the unit factor of Mendel was called gene by Johansen. Johansen was the scientist in 1909. Actually the name has changed. Function remain the same. Gene is the unit of inheritance which is carried from parent to gamete. Gene is unit of inheritance which is carried from parent to parent by gamete. So we can't hear you. Now? Yes sir. Yes. You people should reply a bit okay. You should reply because let's see what I want to tell you all. This is the structure of a chromosome. What? These two are what? Sister. Chromatic. Okay. Yes or no? So if capital T is the allele present over here what do you think? Which allele should be there at this place? Capital T or a small t? Or it can be either. This should be capital T or a small t. At this point. This point. If here it is capital T what should be there at this place? Now Pranav, am I audible now? Yes. Let's see what I want to tell you over here. What I want to tell you over here. One more chart is there. Yes. I am saying in this chromosome in this chromosome if here capital T is there what should be there at this place? Should it be capital T or a small t? Please reply. Yes. See if you will try to understand how this second, second allele is formed you will get to know. Am I audible to everybody now? You can reply. You can reply. You can speak up. Let's see. See actually what happens. This is your this is your capital T. During a space what will happen? Only this is going to be replicated. Only this is going to be replicated. Doubling will be there in a space. What will happen? If this t will be copied as it is it should be t only. Yes or no? Yes sir. So it will be capital T only. Agreed? Let's see. These two are homologous chromosome. These two are homologous chromosome actually if I will let you know. And let's see here it is going to be capital T only. If here it is capital T, here again it will be capital T. Agreed? Here it is capital T. Here it will be capital T. If here it is a small t, it will be a small t. Here a small t and here a small t. Agreed? Everyone? Yes sir. Yes. Agreed everyone? Let's see. This condition is this condition is going to be known as t, t this condition is going to be known as t, t and this condition is known as small t, small t. Agreed? This will be known as I am going to tell you how gametes are going to be formed. Getting my point? Let's see. This is a small t. Small t. This is capital T. Small t. This is this is known as homologous dominant condition. This is known as heterozygous condition. This is known as homozygous recessive condition. Yes or no? Everyone? Yes sir. See why it is homozygous? Because both are same. Why it is heterozygous? Because they are different. And why it is homozygous? Because they are same. The reason of being dominant or recessive, it is going to be different. Okay? Now see how gamete is going to be formed. This is your name. For that you need to have you can say you need to have knowledge of meiosis actually. It will divide from here, centromere and this will split into two parts. Agreed? Division will be there from the center like this and you are going to receive this thing and this thing as gamete. So here two will be there from this and two will be there from this. Total four gametes will be formed. Yes or no? From one homologous pair of chromosome. Can you repeat that? I am going to make that only. Let's see. From one chromosome how many gametes are getting formed? Two? Yes or no? So from one pair homologous chromosome how many gametes will be formed? Four. And each will become containing capital T in this case. Here only one type of gamete will be formed. That will be containing? Capital T. Agree everyone? Which will be containing? Capital T. Agreed? Say yes or no? Yes sir. Everyone? Now using the similar funda, how many types of gamete are going to be formed over here? Two types. Two types? One is I am saying how many types, not the number. From one cell there are four gametes are going to be formed always. Yes or no? Yes sir. One will be one will be there which is a small t, a small t and one will be capital T over here. Yes or no? One will be a small t and one will be capital T over here. Agreed? Everyone? Yes. Say yes or no? Yes sir. And from here how many types of gametes are going to be formed? One. Only one that is a small t. If you have some background knowledge of meiosis okay. In that case these are homologous pair. In first meiosis they will separate. Okay into two cells. And in the second meiosis they will divide from here. Yes or no? Yes or no? Everyone? Yes. Agreed? With my points. Let's see. Let's see. These are the gametes that is being formed. And let's see. Two or more alternate form of a gene are called allele or allele morphs. And they are present they are present on the same locus, same locus of locus on known sister chromatid of same locus or known sister chromatid of what? Homologous pair of, pair of chromosome. Do you people know what are sister and non-sisters? See these two chromatids are known as sister chromatids. What? Metids. And these two are known as what? Chromatids. Agreed? This is one pair homologous pair. Getting my point. This one and this one is non-sister. And two chromatids of the same chromosome is known as sister chromatid. Now try to understand my point. Can sister chromatid having two different forms? I'm saying can sister chromatids or sister chromatid chromatids can have two different forms or not? No, sir. No, sister chromatid will not have. And only difference will be there if here it is capital T on other sister chromatid it must be capital T only. Only on the non-sister chromatid you can change that. Yes or no? Agreed? Everyone. Do you people agree with definition of mine? Yes, sir. Everyone? So what is locus? Locus is a position. In DNA that particular place is known as locus. Agreed? Yes, sir. Everyone. Now Mendel's law of inheritance. Mendel's law of inheritance. For that you have to read some of the Mendel's cross because two, three kind of crosses are there. Okay. Some are based on mono-hybrid cross. Some are based on you can say dihybrid cross. First thing that you people must be knowing what is mono-hybrid cross. Mono-hybrid cross. Mono means one. Agreed, everyone? Mono means one. Agreed, everyone? Yes, sir. Mono means one. It means only you are how many characters Mendel has, you can say pair of characters Mendel has taken for his experiments? Seven pairs. Out of that you are considering only one pair. Means inheritance of only one gene is considered over here. Like here I am making the C. What is this structure known as? This is known as punnett square. What? Punnett square. It is developed by a British geneticist, Reginald C. Punnett and it is the graphical representation to calculate the probability of all possible genotype of offspring in genetic cross. Now here you have seen a word genotype and another is phenotype. What? Genotype. What is genotype? It is the genetic composition. What? Like this plant is this is TT. This is genotype. And now if I will see that plant, what it will look like? What do you want to copy this? Yes, you people can copy. Few of you have asked I think Ritu has asked one question on Turner's syndrome and one more student has asked me two questions today. You people are there in the class? Yes, sir. We will be discussing those questions at the end. Yes, sir. Please remember. Now see, genotype is the genetic composition. That capital T, capital T or capital T small t or a small t, a small t is what? Genotype. Yes or no? Now one is phenotype. What is phenotype? Phenotype is the external appearance is the external morphological appearance like being tall, being short, being green, being wrinkled, being round. All these things are what? Phenotype. Yes or no? Read here? Everyone? Are you getting it? Yes, sir. Yes. So what he has done? What he has done? He has taken a tall plant and a dwarf plant. He has made a cross between them. He has made a cross between them. Now see, capital T, capital T is there means condition is this one. Condition is this one. This one. Here also capital T is there and here. So how many types of gamete will be produced over here? Capital T and capital T. Yes or no? Everyone? Everyone? Capital T and capital T and here it is pure dwarf. It is now you see. One gamete is capital T and one is small t. That will unite what will be formed? Capital T and small t. Yes or no? Here. See one gamete will come from this arm and one will come from this arm. You see. Capital T will unite with small t. In that case again what will be formed? Capital T and small t. Agreed? No issues? Here also capital T, small t and here also capital T, small t. Means all will be capital T, small t. Yes or no? Everyone? See over here. This is known as F1 generation. The first filial generation. Yes or no? The first filial generation that is there. Agreed everyone? Yes sir. Now, important thing. He has subjected plants obtained in the first filial generation for selfing. Means capital T, small t is going to be crossed with capital T, small t. Yes or no? Agreed? Selfing. Same plant is used. How many types of gamete will be produced over here? How many types of gamete will be produced over here? Is it two types? One is capital T and one is small t. You all can see over here. Is it like that? Is it like that? Capital T and small t. Agreed dear? Everyone? Yes. And here also capital T, small t. Now try to understand. On this arm capital T is there and on this arm also capital T is there. What you are going to obtain? Capital T, capital T. Here capital T, small t. Sorry, capital T, small t and capital T, small t. And here it is small t, small t. Yes or no? What he has observed? What he has observed? Let's see. He has observed that in the first filial generation all the plants are tall. His first observation. And in the, he was thinking in first generation that he was thinking after seeing the F1 generation that dwarf plant has vanished. Yes or no? Dwarf plant has vanished. Because none of the plant was dwarf. Yes or no? But surprisingly surprisingly he has seen that in second generation one dwarf plant is recovered. Yes or no? Everyone? One plant was tall. One was dwarf. None of the plant was dwarf in first filial generation. He got amazed that none of the plant is dwarf earlier. Anybody can think that dwarf plant has vanished. Something had happened because of that. But he has recovered a dwarf plant in the second generation. Yes or no? For that two things are used. One is phenotypic ratio. Phenotypic ratio. It is tall. It is to dwarf. It will be 3 is to 1. Agreed dear? And this is for F2 generation. What? It is for F2 generation. It is for F2 generation everyone? Yes. And what is genotypic ratio? It is capital T. Capital T is 2. Capital T is small T is 2. Small T is small T. Will be 1 is to 2 is 2. Agreed everyone? Tell me dear? Yes sir. Is it alright? Yes. In this way he has calculated things. This is the mono hybrid cross. Based on that he has given two laws. First law is inheritance. First is law of dominance. Second is law of segregation. Yes or no? Everyone? There are two law that is given. Law of dominance and law of segregation. Yes or no? What do you people understand? You can say as per law of dominance. What do you understand? Let's see. I am going to write about law of dominance. Let's see. Let's see dear. What is law of dominance? First or you can say any character is controlled by discrete unit known as factors. Any character is controlled by discrete unit known as factor from this only he has given. From the mono hybrid cross only he has given this law. Yes or no? Yes. You all are right. This is one thing that is known as factor. Then any character is controlled by a pair of factor. No issues. And in a dissimilar pair in a dissimilar pair, one factor express itself. That will be known as which factor? Dominant or recessive? Dominant. That will be dominant factor. And another is must. And another factor which express itself. That will be known as am I right? Am I right? Yes. Am I right? Everyone. Do you have any doubt in this? Yes. Do you think there is any exception to this? See this condition. Incomplete dominance. Let's see what you people take out from this. See what happened in incomplete dominance. One flower is red. Another flower is white. You see it is capital R, capital R. So how many kind of gametes will be formed from this? How many kind of gametes will be formed from this? Only one. The capital R and a small R from this. So what happened over here? What happened over here? Let's see. The flower obtained in first generation is, first generation is what? It is not, according to law of dominance, it should be which color? Red. But it is not red. It is blend of red and white. It becomes pink. Yes or no? Means red has tried to dominate but not completely. It became what? It became what? Incomplete dominance. And this is observed in a plant known as snapdragon. Which plant? Agreed. Here is the color red. Color red is color red. Yes, I am going to tell you. At the time I am going to tell you. No issues. See there are many hypothesis that is given regarding this. I am going to tell you that. Here red color is not completely dominant over white color. Rather it is incompletely dominant over white color. Yes or no? Everyone? Tell me. Tell me. Yes sir. Yes. Now you see. Now you see. See the genotypic ratio and phenotypic ratio both. Are they same? Yes sir. Can I say in case of incomplete dominance? In case of incomplete dominance what happens? Tell me dear. In case of incomplete dominance what happens? Genotypic phenotypic ratio is same. Is it right or wrong? Is it right or wrong? Everyone. Is it right or wrong? Right. Everyone. Others also. Yes sir. Let's see now. What happens? What happens over here? I will like to tell you all. In this case what happens? See how it is explained this is Gina. This is Gina. Tell me. So it must be responsible for synthesizing something. It is synthesizing something. Okay. And why it is recessive? It is synthesizing less. Yes or no? That is why it is recessive. No? It is similar. This is the hypothesis that is given. Okay now see. In this case the red color is produced in adequate amount. But in this red color is produced in lesser amount. And in this red color is not produced. Okay. So this becomes white. Okay. This becomes pink and this becomes complete red. Yes or no? If two dominant alleles are there it do not work in all the cases but it works in some of the cases. If two dominant alleles are produced together. Yes or no? If two dominant alleles are produced together. In that case what happens? There are more synthesis. If only one dominant alleles is there the lesser synthesis. And if two you can say alleles are recessive in that case even lesser synthesis. Yes or no? Or no synthesis? A great year? Pranab, you got this thing? No. Let's see Pranab. What I tell you? First thing is there expression of all the expression of gene depends on many factor. Many factor. The same gene is expressing itself itself in a different way in many organisms. Oh I think Aditya told me Aditya told me sir then why it is not true for others? Aditya you got it? Expression of gene is not same in all the animals and organisms rather. It do not depend only on the alleles rather on other factors also. Agreed? So they will combine to express themselves like this. Okay? Agreed. Now let's see. One is co-dominance. Do you people know what is blood group? We have discussed no? We have discussed blood group having three alleles. Three alleles and what are they? They are actually blood groups are example of multiple alleles. Multiple. One is I A. One is I B and one is I O. There are three. Agreed? For blood group A. For blood group A it should be I A I A or I A I O. These two conditions are going to refer to blood group A. Agreed? Everyone? Yes. What is blood group B? I B, I B or I B I U. Agreed? Then blood group O, I O, I O and blood group A B for this it will be I A and I B. Agreed? Can you see in blood group A B what is happening? Yes. Can you see in blood group A B? What is happening? Both are expressing themselves equally. This is an example of co-dominance. Agreed everyone? Both are dominating. Means both are dominating together and this is the example of multiple alleles. Multiple alleles. Means more than two alleles are there. Now one thing is there in one individual. Only two kind of alleles is there. Okay? This is the note. What is the meaning of this note here? Tell me. Let's see. In none of the individual there is three alleles. Is it there? In none of the individual there is three alleles. Only two alleles are there. Only two alleles are there. Tell me. You will ask me certain multiple alleles is there for population. In the complete population you will find three types of alleles. But in a single individual you are going to find only two types of alleles. Yes or no? Agreed everyone? Yes. Now one question mother is mother having blood group A and father having blood group B are the possible blood group or offspring? Tell me. Tell me. Please think about it. I have told all the possible. In that case what you should use or not please think about that and solve this question. Yes. Let's see. Sir I have a question about the, I had a doubt about the question. Is it a heterozygous type of blood group? Whenever all the possible type will be asked whenever it is going to be there you have to always consider heterozygous condition only. Because in that only maximum number of blood group will be there. If you will take homozygous only one is possible. Agreed? Yes. So whenever all the possible will be asked you have to take heterozygous only. Agreed everyone? Are we done? All will be there. All will be there. C or blood group A I will consider IA, IO type or blood group B I will consider IB, IO type Agreed? So let's see from here two gametes are possible IA and IO and from here also two types of gametes are possible IB and IO let's see over here. I am going to make a square for them. Let's see IA, IO and here IB, IO what will be there in this box? IA, IB AB type IB, IO, B type IA, IO, A type and IO, IO, O type. All the four are possible. Here everyone we have read this thing. Now the dihybrid cross what do you people understand by dihybrid cross? I am going to tell you one simple calculation by that you can answer anything that is asked. Yes tell me dear So you didn't explain law of segregation previously See segregation is not based on mono hybrid cross. Yes or no? Segregation I am going to explain. I have not explained this thing. Law of segregation and law of independent assortment. I am going to explain together so that actually the thing is we are going to confuse few things. Okay. Law of dominance and law of segregation is there on the basis of mono hybrid cross and law of independent assortment is there on the dihybrid cross. I am going to explain. No issues. Just give me two minutes First learn dihybrid cross. Then I am going to tell you Let's see. Agree dear. Tell me because we get confused how assortment is taking place and how things are getting segregated Okay. That is why I will explain both of them together in one diagram. Yes or no? Agree dear. Do you people agree? You can say agree with this I will explain it together only. Let's see. Dihybrid cross is cross in which inheritance of two characters are studied inheritance of two characters are studied. Yes or no? Let's see. One important thing that I need to tell you Here is round and yellow seed and wrinkled and green seed. Round and yellow seed Round is dominant character for shape and yellow is a dominant character for seed color Yes or no? Wrinkled is a recessive character for seed shape and green is a recessive character for what? Color. Yes. It is a recessive character for seed color. Now see what all are possible from this R will come and from this Y will come. In gamut what I want to tell you people. Let's see. Let me take that diagram first. Okay. Then only things will be better. Just a minute. I'm taking this diagram to explain both the thing segregation as well as independent assortment. Let's see here. The thing is yes. Let's see. Here the thing is this is the chromosomal theory of inheritance. Chromosomal theory of inheritance. See one thing is there. Everyone one thing is there please try to understand YW. This is Y plus W plus. Yes or no? Wild type. Wild type is used for dominant one. Yes or no? Yes or no? Yes sir. Everyone. Now see from here gamut will be formed. Gamut will be formed. Let me take one more diagram. Otherwise you people will confuse. See this is the cell. After then I will explain that see. First thing you should be knowing let's see. This is a cell okay. For say this is the cell everyone will try to understand this thing. Let's see. From here here is capital R capital R and capital R capital R. This is there. This is R condition and here is capital Y capital Y and here is capital Y capital Y combination. Yes or no? Everyone is it there? Similar thing is there. Similar thing is there. Similar thing is there. Let's see. What is going to happen over here? Let's see. I should make it with some other color. See this is a small r. Small r sorry. A small r a small r and here is what? Green for green a small y should be written. This is there. Only this is there no? Agreed everyone? This condition is there. Why is going to represent yellow? Are it? Why is going to represent yellow? Agreed? Let's see. What I want to tell you all? This is one cell this is another cell. Which what all kind of gametes are possible over here? Tell me that. What all kind of gametes are possible over here? From this cell one gamete is going to have capital R and another gamete is going to have capital Y. Yes or no? This will be formed. Means this is the gamete one is going to have capital R and one is means more than one type of chromosomes are there no? So during during chromosome will divide like that only. This is your gamete and for from this your gametes like this let's see. A small r a small y this is your gamete number two. Yes or no? Cross is going to happen between them only. Agreed? Everyone? Agreed everyone? No issues? So your let's see r y cross r y you are going to find this. Agreed? Say yes or no? Yes sir. R y cross r y you are going to find this means you are going to have a cell having capital R having a small r having capital Y and having a small y. Now from this how many types of gametes are possible? One is one is with this capital R capital Y with this one is with this capital R a small y Agreed? One is a small r capital Y and one is a small r a small y. These four types of gametes are possible. Yes or no? And if you are going to put them on both the limbs of Panetta square you are going to get this result. I think you people have read about this result. Yes or no? Yes sir. But do you people know how you can calculate a dihabrit cross or trihabrit cross you can say from a mono hybrid cross? Do you people know that? This is a traditional method that you people follow. Agreed? Yes or no? Yes sir. But you are not going to get that much time so that you can calculate this way. You will make one Panetta square and time will be finished. So you are going to have actually the dihabrit cross is a combination of two different cross that is mono hybrid. Are they saying multiply? Yes let's see. I am going to tell you the trick of calculating both the things very quickly. I will write over here dihybrid cross as a combination of mono hybrid cross. Let's see here. What is going to happen? See round is RR. Okay. Round is RR and wrinkled is what? A small R a small R. Everyone wrinkled is a small R a small R. Everyone. What is the F1 generation or first gametes? Let's see about the gametes. What should be the generation one? It is round? Yes sir. Similar way yellow is for seed color. Capital Y and green. Is it there? Let's see gamete will be capital Y here it will be a small Y. What is going to be the F1 generation? The generation F1. Agree everyone. Now I will write about F2 generation. Write about F2 generation. What is the genotypic ratio? It is RR is to RR is to RR. It is 1 is to 2 is to 1. Everyone and what is phenotypic ratio? It is round is to wrinkled. It will be 3 is to 1. Agree? Everyone. Is it like that? Everyone. Is it like that? Yes sir. And here F2 generation. What is the genotypic ratio? RR. Sorry. Why sir? Yes. Capital Y is to capital Y is small Y. It is 1 is to 2 is to 1. And what is phenotypic ratio? It is yellow is to green 3 is to 1. Agree everyone. Let's see. Somebody is asking you question is what will be the percentage of round yellow seed? Tell me. As they have asked you round yellow round is 3 yellow is 3. Out of 16 it will be 99 it will be 9. Yes or no? Yes sir. Round yellow. Round 3 yellow 3. Out of 4 it is 3. And out of 4 it is 3. So it will be out of you can say 9 out of 16. Yes or no? You can just see how many round yellow seeds are there. Calculate from the diagram or the photo. It is 9 into 100. Means 9 by 16 into 100. Will be the answer. Agree everyone? Yes. Now calculate round green seed percentage. What will you say? Round is 3 and green is 1. So 3 by 16 to 1. 3 by 16 into 100. Now what will be there if somebody will ask you calculate percentage of seed having genotype R R Y Y. Can you calculate what is the percentage of R R? So what is number 1? So it will be 1. And what is Y Y? So it will be 1 into 2. Means 2 by 16. Yes or no? Everyone. You can easily observe from here what how many are capital R capital R capital Y a small y. You will find only 2. One is here, another is here. Now try to understand my point. 2 laws are there. 2 laws are there. Law of independent assortment. Law of independent assortment. This is based on what? This is based on die habit cross. Whose question were there? Earlier you have told me sir you have not explained law of segregation. Somebody was saying no? So Shraddha here. Shraddha. Let's see Shraddha. What is there? Independent assortment. Means this is moving independent of this round thing. Yes or no? Agreed? They are making independent combination. This R can come with this Y. This R can come with this Y. This Y can go with this R or this Y can go with you can say this R. Anything can happen. If they are means you can say out of two homologous pair this is one pair and this is another pair. Means movement of homologous two different homologous pair of chromosomes are independent of each other. Means what I want to tell you over here that assortment of getting my point means one important thing is there. And one thing is segregation. It is based on mono hybrid cross. Let's see what happens actually this law is saying after you can say observing generation one earlier people had thought that there is some mixing with. There is some mixing between capital T and small t. That had happened. But what after generation has explained it has not happened. The capital T is capital T is getting recovered at the end. Yes or no? Means capital T and a small t. They are segregated. They are separate. Yes or no? They are moving separately. Agree dear? Everyone. And if you have to explain. Sradha got it? Yes sir. And what is independent assortment for that you require at least to separate homologous pair of chromosomes. Means movement of each homologous pair is independent of each other. That is going to fall under law of independent assortment. Yes or no? Everyone. Any doubt? Any doubt? Everyone? No doubt sir. Means allele are not getting blended. That is the observation based on F1 and F2 generation. In F1 generation people have thought that the alleles get mixed up. But the F2 generation has showed us that gametes are not mixing up. Rather they are going to recover as it is at the end of F2 generation. Yes or no? So what is law of segregation? This is based on the fact is based on the fact that alleles do not sow any blending. Getting my point. As both the characters are recovered as it is in the end. Agreed dear? Agreed? No issues? This is law of segregation. Clear? Sradha are you clear now? Yes. And what is law of independent assortment? First it is based on dihibrid cross. At least two homologous pair of chromosomes is required to study this law. Getting my point? No issues? No issues? Yes sir. And what do it say? What do it say? Two pairs of two pairs of I am going to tell you the statement first. Two pairs of what? Two pairs of characters. Agreed? Tell me dear? Or traits are combined in a hybrid. When two pairs of I am going to attach when over here. When two pairs of traits are combined in a hybrid, segregation of one pair is independent of the other pair. Agreed? Means how round is segregated, getting segregated? It is completely independent of how yellow and green is segregated. Yes or no? Tell me everyone. Tell me everyone. See what is happening over here? This YW getting my point. In F2 generation you see gametes are possible over here. How many gametes are possible over here? YW getting my point. Y plus W plus. They are there. Observe this thing. Leave the percentage. That is going to confuse you people. This is some other concept. This is the phenomena of linkage. You need not to you can say learn this thing. Yes I am going to scroll that. You see from here Y plus W plus. This is going once with this. Although here crossing over is being shown I think I should make one different diagram for you people. By applying law of muses. Let's see. Let's see. Give me a minute. You people will confuse in that diagram. I am trying to explain but you will confuse more. Let's say this is your cell. This is your cell. Agreed? Do you know how chromosomes are going to arrange themselves? Arrange themselves on equatorial plate? Yes sir. In meiosis? In meiosis one it will be like this. The two homologous chromosomes will be there. Like this. See what is segregation actually? From that only I will let you know failure of segregation is there. Let's see. Here is capital R capital R and here is small r and a small r. Here is let's see a small r sorry capital Y capital Y is there and here you can see small y small y is there for say. I am going to explain you people in this already. See. One condition is this and one condition is this. When it will be separating with this small r small r small y small y can come. Yes or no? Means these two will come towards one cell and these two can come towards another cell. Yes or no? Everyone? Everyone? This is segregation. Agreed? Say yes or no? Yes sir. But arranging themselves on arranging themselves on equator is a random process. Nobody can say what will go and how it will go. Let's see. It can happen another way. It can happen another way. Let's see. What can be there? These can be just a minute. These can be a different story also. Let's see. Here a small y small y small y small y and at this place at this place capital Y capital Y and capital Y capital Y is there. Agreed? Now you see in this condition with capital R capital Y is going now? Yes or no? Yes sir. And in this condition do you know what is happening with capital R? With capital R a small y is going. Yes or no? So both the conditions are possible no? Yes sir. Both the conditions are possible. Is this thing affecting this thing? If they are going to affect some kind of affinity is there in that case they should go together always and they should go together always. It is not happening again. Agreed? Yes sir. So this is the law of independent assortment. Agreed everyone? Sadha understood here? Yes sir. Yes. Please see to it. I am joining you back in a minute. Yes everyone. Am I audible now? Yes sir. Yes. You people have understood that law of independent assortment and law of independent assortment. Just let me take the attendance first. Otherwise I will forget. And that calculation of dihybrid cross is very important because that is very time taking job. Okay? So likewise you people can calculate trihybrid cross also. Like you can say as a combination of three mono hybrid cross. Yes or no? Any cross you people can now. Five minutes break. Yes you can have. You can have. No issues. We will start at seven ten. Everyone agreed? Yes. Aditya having one doubt. Sir why student? Why, why? And capital Y, capital Y and small y, small y move together. In which case dear this one. See I am talking about second generation. You can say I am talking about second generation. In that case this had happened. Agreed? Capital R small r. Capital Y small r y is there no? The main thing is there. I am telling you people this is one homologous pair of chromosome. Okay? This is another in a cell. How this will move do not depend on this. Yes or no? Agreed? Aditya? So have the a little spin pump. Yes it will form later on. See this is meiosis one. I am going to show you the result once take a break. Okay? Break will be over by. Yes everyone. I am back. Are you people there? Yes sir. Yes let's see. See how the chromosome will move I will explain it a bit in meiosis part. Okay? Alice will be formed. Getting my point. If you have you can say little bit knowledge of meiosis one and meiosis two you will understand. I will explain this thing at the time of meiosis. Don't worry. This is done. This is done. Now exception is done also. Agreed everyone? Now the sex determination. One is xx, xy type. Getting my point. One is xx, xy type. One is xx, xo type and one is zw, zz type. Let's see. In this if you will see you will see xy is the male and xx is female. Agreed? Everyone? Everyone? Male is xx and female is xy. Agreed? Everyone? Sorry. I have written this thing. Male is xy and female is xx. Agreed? Done? First female is written and then male is written. Yes or no? This is a notion. Yes. Let's see. Male will form how many types of gamete tell me dear? Two sir. Two. One is x and one is y. And how many types of gametes are going to be formed by female? One. Only one type. Agreed? Type is only one. Everyone? Let's see. I am making only one. This will combine with female. They will combine. Done? In what all organism it is there? It is found in mammals. You can say human is there at least. Drosophila. Agreed everyone? No issues? No issues? No. In female, xy is male. Let's see. Here. This is known as male hetero gamete. Even this is male hetro gamete. Agreed everyone? Let's see what happens. Here female is x, x. And male is x, o. O means nothing. Female will form only one type of gamete. That is x. Male will form two kind of gamete. One gamete is there with one x chromosome. Another gamete is without any x chromosome. Yes or no? One gamete is there with x chromosome and another gamete is without any x chromosome. If they will combine, they will form x, x condition female and if they will combine, they will form x, o condition that is male. Everyone. Tell me, dear. Tell me. Any doubt in this? No issues? And this one, the ZW, ZZ type. The example of female hetero gamete. Here female is ZW and male is ZZ. Z, W, X and Y are a bit of representation and or it depends on shape of the chromosome also. Female is going to have two kind of gamete. And W and male will have only one kind of gamete, ZZ. So if they will combine, it will form ZZ. If they will combine, they will form ZW. This will be male and this will be female. Agreed, dear? Tell me. ZZ. ZW is found in birds. Birds. Okay. Moths are there, I think. Agreed. And in which animal x, x, x, o type of you can say sex determination is found. It is there in the insects. Many insects. No issues? Tell me. Okay. An insect also, as I remember, it is grass offer. What? Agreed, everyone? Do people agree with this? Tell me. Yes. Everyone? Yes, sir. Let's see. One is Genic Balance Theory. One is Genic Balance Theory. You people can observe over here. Please observe. What is Genic Balance Theory? Please read it out. Actually, this is given by, this is given by Sir C.V. Bridge, Calvin Bridge. He has stated that, means earlier we used to think that in Drosophila it happens, not in human. He has done this experiment in Drosophila melanogaster only. So, he has observed that it is the ratio of X chromosome and autosome which is going to determine the sex, not only the X chromosome. Yes or no? Or Y chromosome? Agreed? Tell me. Yes, sir. No issues? No issues? Now, see this condition. X, X, X, 2A, they are autosome. The ratio will be 1.5. It will be superfemale or metafemale. Just a minute. I think it has stopped. Just a minute, dear. Just a minute. Just a minute. Screen mirroring has stopped. I'm just starting, re-starting that. So, we can see your screen. Can you see? Yes, sir. No, you can see the screen actually. Okay, you can see the screen of my laptop, not my iPad. Yes, sir. Yes or no? Yes, sir. Yes. Suddenly that has stopped. Just a minute. Just a minute. Just a minute, dear. Am I audible to you? Am I audible now? Yes, sir. See, the thing that is there, it is told by Sir C.B. Bridge. See, here is, screen is visible now? Screen is visible now? Actually, at times this happens. Is it visible now? Yes, sir. Yes, let's see. What happens? He told, it depends on the ratio actually. Getting one point? 1.5 is superfemale. Okay? And 0.5 is male. If ratio is going to be 1, it is female. Actually, this is based on certain studies. There is no clear logic behind it that C.B. Bridge, here, you can say, has given. Because in human, it is clear that why chromosome having certain factors that is going to suppress the formation of female reproductive tract. But it is not there in the drosophila. If it is 1.5, you can see, number of X chromosome is 3 and here it is 2 autosomes, so 3 by 2, 1.5. Autosome, you people understand autosome, you people understand. Tell me. Yes, sir. Everyone. So, this is there. You people can read a bit. Great, dear. Anybody else having doubt in this? I think one, anybody else having any other doubt in this? Let's see. One more thing I would like to discuss over here. There are certain syndromes. Sir. Yes. Can you just show the table again? Yes. Genic balance theory. After that, you people read your you can say textbook very nicely. Okay? Because most of the questions will be there from the basics only. One can go up to higher level. So, basic things would be done at any cost. Thank you, sir. Everyone. Now, certain syndromes are there. Certain syndromes are there. Agreed, dear? One more thing. Do you people have any book for KVPI previous year? Yes, sir. Okay, I will try to send some questions. Yes, past year papers. Yeah. Yes. You can download also. See, what is down syndrome? See, what happens? It is due to trisomy of chromosome number 21. It is due to autosome. Okay. No issues? Chromosome number 21. Trisomy. You understand? What should be there? Ideally, during the segregation, during the segregation, yes, in class. Let's see, dear, whenever this thing will happen, like known disjunction kind of thing, they will not go to even say opposite poles. Both will be taken to one pole only. In this case, see, three sets will be there of any chromosome. That is known as trisomy. Usually, how many sets would be there? Only two. Deployed condition. Yes or no? Agreed? Yes, sir. So, this is due to trisomy. You remember this thing. That's all. Clean filter syndrome. This disorder is also caused due to presence of an additional copy of X chromosome, resulting in a karyotype of 47. This person becomes 44 autosome plus X, Y. In this case, do you know? It will become 47. Agreed? Now, such overall masculine development. See, whenever this Y chromosome is there, only masculine development will take place. Yes or no? Because I have told you Y chromosome having Y chromosome having what? Tell me. Y chromosome having certain factors which is going to do what? Certain factors. Yes. Which is going to suppress the family in development. So, why is there masculine development will be there? But, as two X chromosomes are there, as two X chromosomes are there, in that case what will happen? Certain exaggerated, you can say female character will be there in the male, like gynecomastia. It is the enlarged memory gland. Yes or no? Enlarged memory gland. Agreed? Everyone and individual will be esterized. One is their Turner syndrome. Tell me dear. In this 44 plus X, O will be there. Means Y or X, another Y or X chromosome is missing. Total number of chromosome will be 45. Agreed? Agreed? Everyone? So, this individual will be a female. Agreed? This individual will be a female. Why? Y chromosome is not there. Agreed? Tell me. I think now you can ask me what is your question? Yes. Yes sir. My question was, is it only the female during sexual intercourse does only the female not have the X chromosome or does the male not form a sperm that has X? See, this is there. X can be there. X can be there from the male or female, both. Yes or no? Agreed? Yes sir. It is there. If X, O condition is there no? If X, O condition is there, in that case one of the X chromosomes is missing. In that case even, female can be there try to understand my point. Then you will understand not your O. If female is X, O, try to understand my point. In that case one gamete will be O also. And male cannot be Y, O, like C. If male will be Y, O means X chromosome is missing. In that case, never ever, try to understand my point. If male is Y, O, in that case what will happen? This gamete can be the first condition is female is normal male do not have Y chromosome. In that case what will happen? This person will become this is having Turner syndrome. Yes or no? Yes. Now the second case. Now the second case. Male is absolutely normal. Female is X, O. In that case also you can see if they will combine, it will become X, O. It is a chance you cannot say in which case it is going to be there. Understood? X can be missing from any of the parents. Agreed? Agreed? Ritu? Yes, sorry my internet understood. Now one question were there from the, I think based on modification of leaf. Whose question were there? Sathya, you have asked the question. Also. Tell me whose question were there? So yes. Sir, I have another question. See here somebody have asked me over here one question that which one of the following is modification of leaf? It is onion. Yes, Sathya, you can ask me question. Which phone number is there ending with 4, 5, 6? Farnab, you have asked? Yes. Okay, okay. Let's see answer will be onion only dear. Onion is the modified leaf only. Agreed? Agreed? For the first question, answer will be which of the following is a modified leaf? It will be onion. Modified fleshy leaf for storage of food. Next question is C. You have started from the cell membrane. A line drawn from exterior of animal cell to center of nucleus crossing through one mitre. What is minimum number of membrane by layers that are that the line will cross? See, one is over here. One is in the mitre conria and one is the nucleus. Two will be crossed over here. Two, two, six. It will be more than six, I think. Let me think I will send you the answer. I think question is not right. Okay. Sir, there was one about evolution. They had asked they had put a rabbit in an island and they had let it grow. They asked what would be the graph of the population? They are a single rabbit is put in an island and there is good food and there is no disaster. What would be the graph of the population? See, single rabbit is there means no predator is there. Initially it will grow very rapidly. Very rapidly. But after some time the environmental factor factor will become limited and after that it will stabilize. Yes or no? Yes. The predator is not there. Any animal is going to grow or plant is going to grow very rapidly. But all the environmental factors are going to be there in place. Once its resources will be limited, you can say, will be exhausted and then the population is going to crash. Either it will stabilize or it will go like this. It can decline also. Agreed? Like if plants are vegetation is not growing. In that case it will decline also. Agreed? Yes. But it is more likely in my opinion. The question is there with you. You can send it to me. Yes. Sir, what is your question? Tell me dear. Sir, could you just explain that part where you said 44 plus XXY gives you 47 chromosomes and that calculation part again? 44 is the autosome 44 is the autosome, 2X chromosome 46 and 1Y chromosome, 47. So you are taking each of them as one chromosome and not them to one single thing? Yes, that is one chromosome only. We have 22 pairs plus XX or 22 pair plus XY. If I have written 4 here, that means I have counted one chromosome. Okay, one homologous pair has 2 chromosomes. Yes or no? So if Y does not have the other part of it, it will still be counted? Yes, it will be counted. In number of chromosomes either you say pair or if pair is not there, in that case total number of chromosomes will be counted. Yes or no? Y is always single. What you do? 22 pairs, autosome plus 1X, 1X and 1Y. So it will become 44 plus 45 plus 1 plus 1. It is 44 plus 145 plus 146. Agreed dear? Yes. Read your, you can say, next book very nicely. If you have any doubt, you can send it to me. Now exam time is there. You can ask me for doubts. You can connect to me some other time also apart from the class. Sir, Aditya, what is, isn't it 3? You are saying 3? For that question, let me think again. For that question, Aditya, oh, membrane question, let me think. If you are here to discuss, I am going to discuss that. Let's see. See, this is one membrane bilayer. Mitochondria is bilayer, one and then nucleus is also bilayer. So one is this, 2, 3, 4, 5. 5 is answer, let's see. 5 is there in the option. It is not there. That is why I am saying, let me think. Is there any modification in the inner mitochondrial membrane? Aditya, why it is there? How you are saying 3? Because mitochondria and nucleus is bilayer, no? Sir, isn't the cell membrane is also... Cell membrane having? Sir, cell membrane having two layers, right? See, that is why I am counting this as, I am counting this as one bilayer. I am counting this as one bilayer. Agreed? This is one bilayer. This is another bilayer. This is another bilayer. All are unit membrane only. This is another bilayer. So there should be 5 in option. Let me check it once. Okay? If at this time I am missing something, I am going to let you know. Sir, actually it was a bonus question. The answer was 5. Okay? That is why I am telling you people. Understood? Understood? Yes, sir. Okay. Bye everyone. Thank you, sir. Okay. If you people have any doubt and any question, you can send that question to me anytime. Your exam is going to be there and any topic is there that you need to understand. You can contact me personally also. I will see to it. Okay? Thank you, sir. Thank you, sir. Thank you, sir.