Genetics - Laws of Mendel II Mendel's laws of inheritance and the phenotype & genotype ratios obtained.

Genetics - Laws of Mendel

Genetics - Laws of Mendel

we'll talk about the laws of principles of inheritance and these laws are based on the research that was done by Mendel and that these laws are also known as Mendel's laws of inheritance the first law is the law of dominance the law says that if we start with pure line in the first generation or in f1 the character or trait which is expressed is the dominant trait to understand this law real estate one simple example suppose we start with a pure life that is pure talk homozygous tall crossed with pure short or homozygous recessive or homozygous dwarf this is the parent generation and we are starting with pure life in Mendel's laws of Mendel's inheritance we always start with your life the gametes produced by this plant would be with capital T or dominant adil whereas in this land it would be with recessive AG and when we plot a few men square to see the offsprings or genotype of the offsprings in the next generation we write the gametes produced by this plant on this side and the gametes produced by the pure homozygous recessive on the other side and if this gamete is fertilized by the male gamete which we have put on their side the genotype of the offspring is going to be heterozygous in all four but phenotype equally due to the presence of four dominant gene all of them are going to be tall so if we write the phenotype ray show phenotype ratio it's going to be four is two zero four are going to be tall and none of them is short and if we talk of genotype that is the ratio based on the genotype the ratio is going to be an N for us to zero all four are heterozygous tall so they are heterozygous tall so when the loss is starting with the pure line in f1 the tail which expresses itself is the dominant and here the dominant rate is tall so this is law of dominance the second law is law of segregation second law is law egregation segregation means separation now it is a law of segregation we need to understand what exactly this law means it says that out of the two atoms one goes on each gamete or in other words we can say during gamete formation the two atoms of the gene get segregated or separated if the parent is homozygous tall then these two will get separated during meiosis or a gamete formation we know in meiosis which is the reduction of division half number of chromosomes would get into the gap so if you are starting with these two one gamete would get this another gamete would get this if the parent is heterozygous then one gamete would get the dominant allele and the other gamete will get the recessive at this period or this type of organism is termed as homozygous and because both the islands are dominant we call it homozygous dominant this individual is heterozygous because it has one allele as prominent another analyst is recessive so this can be termed as pure also and this is heterozygous in case of a pure of individual the Gammage would have the same type of a dominant or recessive allele here one camel has drawn with other gamete has just excess but if we talk about only the garden this gamete is pure for that particular atom here it was not pure because one on one was of the dominant type of necessity in this camp that's only one ally and that is dominant in this handedness only one island that is recessive so these cabins are pure for that particular area and that is 

Genetics - Laws of Mendel

Van Gogh segregation is also known as the law of purity of gannets reason being the gamut is having only one of the eyelid so there is no heterozygous condition so law of segregation says that the gametes would get one either out of two or the two islands of one gene gets segregated or separated during gamete formation and the reason for giving this law another name is that one government has only one atom of that gene which is pure for that now the third law can be understood if we understand dihybrid cross in case of monohybrid crosses we were able to understand the law of dominance and law of segregation to understand the third law that is the law of independent assortment the independent assortment we need to take a dihybrid cross so here we have to remember that this law can be explained only by using a dihybrid cross whereas the law of dominance and segregation can be explained using 100 as and records here we will start with a dihybrid cross and then we'll come to what exactly is meant by this independent assortment as we are talking of Mendel's laws we'll start with what was told by Mendel that is we start with pure life so parent germination is going to be pure for two characters now say we are talking of tall and perfect so this is homozygous tall homozygous for pure for tallness and pure for purple it is crossed with a pure short and

Genetics - Laws of Mendel

white that means homozygous for short or broad and white if this is the parent generation in f1 or let us talk about the gamete formation first in this the Gammage would have one of this and one of these so one T and P but here because we started with homozygous tall and purple it is going to be capital T and capital P and there are four gametes which would be produced here by four gamuts the reason is that this T can go with this speed this team can also go with this P or same exactly Capel with the other teeth so there are four possible ways in which these T and B atoms can go together and this is what is exactly the independent assortment but we'll be able to understand it come to the f2 so gamuts are going to be TP for yards and in case of the recessive parent all four garments are going to be with recessive that is recessive or tall this is for short and white so forum for gannets now if we plot Putin square we will have to write for gametes produced by one parent on one side and four gametes produced by the other gamma parent on the other side if we write capital TP lowercase TP here then the offsprings which would be produced would have capital T from here and work is T from here capital P from here and lowercase P from here so there will be heterozygous for all this and barber all 16 of strings are going to be heterozygous tall and heterozygous purple law of dominance can be explained heroes in f1 the clip which expresses itself is dominant that is tall and purple and all 16 offsprings are showing this dominant ring so glove dominance told us or star says that if we start with few f1 it is only the dominant trait which expresses itself so here we have explained a lot of dominance also now if we go for self it of f1 selfing as we had already discussed selfing means when the offsprings of the the same generation is crossed then it is known as selling so if we perform self in of the members of f1 we will get the next generation that is f2 so let us talk about f2 now so that we can understand this law of independent assortment again in a slightly better manner heterozygous these were no offsprings of f1 now here we are using them as parent for the next generation know what type of gametes would be formed capital T can a short itself or go with capital P capital T can also go with lowercase P independent of what is the other P like lower case T can go with capital P and lower case T can go with lowercase P that means adorned with it I the will can go with a dominant allele of the other G as well as the recessive allele of the other

Genetics - Laws of Mendel

G so independent of the other others these abbreviations can go with any owners independently irrespective of whether the other P is capital or lower is or dominant or recessive they can go with any of those now again when we say in deployment this is one G to Ellis one Ellis dominant that is represented by capital T it can independently assert itself with capital P we get this gamete or lowercase P we get this cat and why we are saying independently because it is not dependent on what is on the side of it whether it is lowercase T or capital or dominant so this is the law of independent assortment and one this and this we need to take a dihybrid cross so three laws dominance law of segregation can be explained using both monohybrids as well as dihybrid crosses but the law of independent assortment can be explained only by using a dihybrid cross because there it is clear to explain that the allele of one gene can independently assort with any of the other genes so three laws of Mendel's now we will talk about some crosses you

Mendel's laws of inheritance and the phenotype & genotype ratios obtained.

To help students search for a topic easily, all the channel videos have been archived chapter wise on www.onlinenbt.com