If Females as XX and males have XY is is possible to create a person with YY, and what do you think they would be like?

In the Y chromosome a lot of genes are effectively silenced. As such a YY karyotype is probably not viable. XYY occurs, though.

so what happens when the XYY appears?

Not a lot usually, slight chance of reduced intelligence, but that's about it really. Bare in mind that the Y chromosome is still mostly silenced regardless. There may be some gene dosage issues since there are two SRY genes, but I don't think that's anything special compared to other structural variants and CNV's.

Someone with YY would die well before being born. I've heard that those with XYY are more violent, but I just looked that up and it was an old misconception. It is also possible to have XXY, XXX, X, XXYY chromosomal arrangements. They are more common than you would think...

I am just curious,is there even a slight possibility that a YY individual can be produced?Since normal females generally carry two X chromosomes they provide only X gametes and the Y chromosme can only come from a male, so how is it viable then that a YY individual would be even conceived?

I am just curious,is there even a slight possibility that a YY individual can be produced?Since normal females generally carry two X chromosomes they provide only X gametes and the Y chromosme can only come from a male, so how is it viable then that a YY individual would be even conceived?

It isn't possible to have YY as most of the genes are not only silenced but not even present.

 

XXY causes Klinefelter's syndrome, X causes turners syndrome.

 

Most chromosome ploidy conditions result in infertility.