Now, in contrast, if we look at the Y chromosome, the Y chromosome only usually has one or several genes that are involved for giving that male their maleness. Now, whenever we're looking at genes on the X chromosome, those genes on the X chromosome are known as sex linked genes or X linked genes. And that's because these are the genes that express proteins that are necessary for the different types of traits that exist in males as well as females. So let's take a look at the female and then let's take a look at the male. So we know that in the female, the two types of sex chromosomes are the X chromosome and the X chromosome. Now, we know that a gene can either be dominant or a gene can be recessive.