The two normal types of sex chromosomes are

The two normal types of sex chromosomes are XX and XY. Sex chromosomes determine the biological sex of an individual. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). During sexual reproduction, each parent contributes one sex chromosome, either an X or a Y, to their offspring. If an individual inherits an X chromosome from both parents, they will be female (XX), while if they inherit an X chromosome from their mother and a Y chromosome from their father, they will be male (XY). Therefore, the two normal types of sex chromosomes are XX and XY.