True or False: Men have both X and Y chromosomes.

Men indeed have both X and Y chromosomes. In humans, the typical chromosomal arrangement for males is one X chromosome and one Y chromosome, making their chromosomal composition XY. The presence of the Y chromosome is what typically determines male sex characteristics, while the X chromosome carries various genes that are important for both males and females. This fundamental genetic makeup plays a critical role in biological sex determination and is consistent across the vast majority of human males.

The other options suggest scenarios that do not accurately reflect the standard chromosomal configuration in males. The idea that men might only have one of the two chromosomes or that their chromosome structure depends on genetic modification is misleading since the typical male karyotype is well-established and does not require alteration to exist.