Flexi Says: The sex of a baby is determined by a special pair of chromosomes known as the sex chromosomes. Recall that you have 23 pairs of chromosomes—and one of those pairs is the sex chromosomes. Typically, each person has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). In some cases, people can inherit different numbers of sex chromosomes (e.g., XXY, XYY) or can have malfunctioning proteins that affect sex characteristics. These people have atypical combinations of sex characteristics, generally referred to as intersex.
