hi today's question would be theoretical and the question is what are the types of sperm that could be in principle be formed by x y y male so as you see here we have tristonomy of the sex chromosome so we have two yy chromosomes and one x chromosome and phenotypically this is going to be a male so let me write down this information one more time so this is going to be karyotype of a person and imagine that if during my uses the division would be here and then gametes would be formed or two sperms one would have x chromosome and another one would have two yy chromosomes so this is one variant and the second parent so the same genotype of the male and imagine that division would be here so we would have x y genotype here in one gamete or sperm and y in the other garment so as you see three out of four would result in a male so this is it would be a male and this would be a male and this also would be a male and here would be a female so if we built a punnett square and this is going to be a genotype of the father x y y and if we cross with a female whose genotype would be x x and as you see we can have here four different types of gametes so let's list all of them so we can cross with x y y x y and y gametes so now let's build the planet square and find the genotypic and phenotypic ratios so we would have here four columns and two rows so here we would have x x and this is going to be a female and here we would have x x and this is also going to be female and here we would have x y y so this is going to be a male ml here and x x y here and this is also going to be a male because whenever we have at least one y chromosome this would means that phenotypically this is going to be a male so x x y here and x y here and x y here so as you see uh we would have two females normal phenom females genotypically normal and phenotypically of course and two genetically and phenotypically normal males here and also we would have here about four out of eight um genotypically abnormal uh genotypes so as you see this is going to be 50 and this is going to be 25 percent and 25 here and as i told earlier the phenotypic ratio going to be one female two three males because all these genotypes here would be phenotypically males so uh what also i want to add that this is just a theoretical we can call yield just like in chemistry but in real life just like in chemistry theoretical yield never can be reached but here for the different reasons and in order to prepare for this video today i made uh some research i didn't find information about x y y and x x y genotypes but i did find information about clinical filter syndrome and this is when we have x and 0 we also can notate it as x or x 0 and this is when we have phenotypically female but female going to have only one x chromosome and this genetic disorder happens uh one per two thousand five hundred life births but if we study fetus material from self abortion we would find that uh seven percent of all self-abortion would be due to this unemployed when we have clinic filter syndrome when we have one x chromosome in females so as you see the mother nature works very efficiently and in most of the cases such pregnancies would self-abort and that's why we have only occurrence of this genetic disorder only one per 2 500 life born girls and the same picture we can expect here where the theoretical occurrence of this genetic disorder should be 50 in the progeny but in the reality this can be 50 folds less than this theoretical prediction so in reality we may have here only about one percent and that means that this two percentages here would increase and would make about 49 here and about 49.5 percent here so as you see total number would be 100 but here this genotypes wouldn't be represented as 50 in the progeny but most likely like about 1 in the progeny so uh people with this xyy syndrome usually this syndrome even doesn't have a special name because this is not actually a syndrome people who has one extra y chromosome also sometimes called as super males actually phenotypically normal this people are fertile and they just may be a little bit taller than uh normal people who normal males who is x y by average about 3 inches this is about 7 8 centimeters and also i want to mention that due to some work made by nelson in 1968 where she reported that she find people in the prison that has unusual frequency of accuracy of this genetic disorder and this information were picked up by many popular magazines and journals but i also want to tell you that first of all this information was published in non-peer-reviewed journal so as it turned it out to be that scientific information were not valid because the sample was just two people should only find two people with x y uh sorry with one extra y chromosome and she made her assumptions on this findings and as you see this idea got very popular and you even can find this information in some textbooks that people with this extra y chromosome might show a violent character and you may find a high frequency of this genotype in prisons but once again this is not true and we can call this as a urban tale and my final note would be i just want once again bring your attention that phenotypic ratio males and females would be about 50 to 50 percent or one to one and this is what we normally find uh actually we find phenotypic ratios would be um 49 girls and 51 boys and usually it's explained uh that uh sperm and uh the gender or sex of the progeny depends on the male on its sperm whether it is x or y chromosome in the sperm and because y chromosome is much smaller than x chromosome so it's believed that such sperm moves a little bit faster because it's lighter and that's why we have such ratios as 49 to 51 at the stage of the life birth but by the age of them about 18 and 20 we would have ratios about 50 to 50 percent exactly and this is all for today thank you for attention please subscribe for my new videos 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