Question

Which of the following human karyotypes does not exhibit ANEUPLOIDY?

1) Klinefelter syndrome (47, XXY)
2) Turner syndrome (45, X0)
3) Down syndrome (47, +21)
4) Edwards syndrome (47, +18)

Answer 1

Turner syndrome (45, X0) does not exhibit aneuploidy; it is a condition of monosomy with a total of 45 chromosomes, while Klinefelter, Down, and Edwards syndromes all involve an extra chromosome and are considered aneuploid.

Step-by-step explanation:

The human karyotype that does not exhibit aneuploidy is Turner syndrome (45, X0). Aneuploidy refers to the presence of an abnormal number of chromosomes in a cell, which is a form of chromosomal abnormality. In Turner syndrome, the individual has a single X chromosome and no second sex chromosome (either X or Y), leading to a total count of 45 chromosomes instead of the normal 46. This is a condition of monosomy, which is technically not considered aneuploidy.

Klinefelter syndrome (47, XXY), Down syndrome (47, +21), and Edwards syndrome (47, +18) all involve the presence of an extra chromosome, making them cases of trisomy, a type of aneuploidy where there are three instances of one chromosome instead of the usual two.