Final answer:
The statement is true; Klinefelter syndrome results from an additional X chromosome(s) in males, causing characteristic symptoms such as small testes, enlarged breasts, and reduced body hair.
Step-by-step explanation:
The statement that the presence of one or more additional X chromosomes in a male leads to Klinefelter syndrome, characterized by features like small testes, enlarged breasts, and reduced body hair, is true. Klinefelter syndrome is typically represented by the XXY genotype. In this condition, every X chromosome except one undergoes inactivation to compensate for the excess genetic material. This process leads to the formation of Barr bodies in each cell nucleus.
Unlike Klinefelter syndrome, Turner syndrome is an XO genotype and affects phenotypically female individuals with distinct features such as short stature, webbed neck, and sterility.
In the context of chromosomal abnormalities involving the X chromosome, issues such as sterility, mild intellectual and physical defects may arise due to the continued expression of a few genes on the inactivated X chromosomes.