In a normal karyotype for males, which term is used to describe their genetic makeup?

• A. XX
• B. XY
• C. YY
• D. XO

Answer: (B)

The correct term used to describe the genetic makeup of males in a normal karyotype is XY. This indicates the presence of one X chromosome and one Y chromosome. The Y chromosome carries genes that are crucial for the development of male secondary sexual characteristics and male reproductive organs.

Females typically have two X chromosomes (XX), which is distinct and indicates a different karyotypic profile. YY would suggest the presence of two Y chromosomes, which is not a typical configuration found in humans and is generally not compatible with life. The XO configuration represents a deletion of one X chromosome, associated with Turner syndrome, which manifests in females with various physical and developmental challenges.

Thus, in the context of normal human male karyotypes, XY is the appropriate representation of their chromosomal structure, indicating that males inherit one X chromosome from their mother and one Y chromosome from their father.