Final answer:
An embryo with two X chromosomes will develop into a female, as females have XX sex chromosomes. The father's sperm determines the baby's sex, with a 50:50 chance of being male or female.
Step-by-step explanation:
Genetic testing showing that an embryo has two X chromosomes indicates that the infant will be female. This is because the sex of a baby is determined by its sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The presence of the Y chromosome is what triggers the development of male characteristics, while its absence results in female characteristics. The sex of the baby is determined by the father since he can provide either an X or a Y chromosome through his sperm, giving a 50:50 chance for the child to be either male or female. Complex chromosomal differences like Klinefelter syndrome (XXY) or Turner syndrome (XO) can lead to various developmental and sterility issues.