Final answer:
Human males typically inherit an X chromosome from their mother and a Y chromosome from their father. The father determines the child's sex by whether his sperm carries an X or Y chromosome. Nondisjunction during meiosis can result in variation in sex chromosome combinations.
Step-by-step explanation:
Inheritance of Sex Chromosomes
The sex of a baby is determined by the sex chromosomes it inherits from its parents; specifically, whether the baby inherits two X chromosomes or one X and one Y chromosome. A human male typically inherits an X chromosome from his mother and a Y chromosome from his father, making the correct answer c. An X from his mother and a Y from his father. If a baby inherits an X chromosome from the mother and another X chromosome from the father, the child's sex would be female, due to the child having two X chromosomes (XX).
During sexual reproduction, male gametes can carry either an X or a Y chromosome, whereas female gametes will only carry an X chromosome. This is because females have two X chromosomes (XX), and males have one X chromosome and one Y chromosome (XY). Fathers therefore determine the sex of the offspring, as a sperm cell from the father can provide either an X or Y chromosome, while the mother can only pass on an X chromosome.
In instances where there are more than two sex chromosomes, such as XXY or XYY in males or XXX in females, it is often due to an error in meiosis, called nondisjunction. Nondisjunction can result in gametes with an abnormal number of sex chromosomes, leading to these variations.