Who determines the gender of the offspring male or female?

The gender of the offspring is determined by the male parent, specifically through the sperm. Human males have one X and one Y chromosome, while females have two X chromosomes. When a sperm carrying an X chromosome fertilizes an egg, the resulting offspring is female (XX), and when a sperm carrying a Y chromosome fertilizes an egg, the offspring is male (XY). Thus, it is the combination of the sperm's chromosome that ultimately determines the gender.