Aside from the obvious biological differences between men and women, we differ in numerous ways, some of which we are not even aware of. The way we look, the way we behave is all part of our DNA. We have different genes, our brains are wired differently, and we have different hormones. We all know that women have two "X" chromosomes and men have one "X" and one "Y" chromosome. The X and Y chromosomes determine a person's sex. Chromosomes contain the set of instructions for creating the living being. The male Y chromosome and the female X chromosome are different sizes and vary in the number of functioning genes. The X chromosome may contain more than 1,000 functioning genes, while the Y has fewer than 100. Several studies have been conducted on the inactive X chromosome in women. “Our study shows that inactive Medical Center. “The effects of these inactive X chromosome genes could explain some of the differences between men and women that are not attributable to sex hormones.” X chromosomes in males. The study says that having two active copies of the gene can matter a lot, or very little. “Although we showed sex-specific differences, the clinical implications remain unexplored,” Carrel said. “We can, however, conclude that these differences should be recognized as potential factors in explaining normal sex differences but also gender differences in how certain diseases manifest, progress and respond… half of the paper… ...much more similar than we might think. We all have 46 chromosomes in 23 pairs and only one chromosome separates us from being male or female. So are we really that different? Gender differences: brain differences." M Alagha. 04 April 2011. WebConner, Steve "Intrinsic difference between male and female brains could explain why men are 'better at reading maps'" The Independent Independent Digital News and Media,. February 3, 2013. Web.DiscoveryHealth.com Writers “Estrogen and Testosterone Hormones” Discovery Fit and Health, nd Web.Penn State “Men and Women: The Differences Are in the Genes.” March 23, 2005. Web.Swerdloff RS , Wang C. The testis and male sexual function. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011: chap 242.