How does a person know if they have xx chromosomes or xy chromosomes?

Answer 1

An X chromosome is much, much larger than a Y chromosome. For this reason, an X chromosome is more important for life than a Y. Let's consider the options you posed:

YY --> because the Y chromosome is so small, there is not enough genetic information for an organism to survive. This is not viable and will not even form an organism.

YYY --> again, same thing. See above.

XXY --> Klinefelter's syndrome. This produces a male with an inhibited reproductive ability; he will probably not be able to produce offspring.

XXX --> Triplo-X syndrome. Because in normal females, one X chromosome is turned off anyways (Barr body) to avoid any extra genetic info, the same thing happens here, only both X chromosomes are turned off. Only one X chromosome is active at a time. There's no distinguishable difference between XX and XXX females.

XYY --> Normal male. Most men who have this genotype probably don't even know they have it.

Answer 2

A person's chromosomal sex can be determined by genetic testing, typically using a blood sample. XX chromosomes are typically found in females, while XY chromosomes are typically found in males. However, there are exceptions and variations, such as intersex individuals who may have different chromosomal combinations.

Answer 3

XX = Female, XY = Male :)