Question

Consider four individuals, where X and Y are sex chromosomes and A is one set of autosomes. Number 1 is XXY:AA, number 2 is XY:AA, number 3 is XXX:AAA, and number 4 is X0:AA. What is the individual's overall phenotype and indicate if it is relatively normal or not. Note any unusual genotypic characteristic that don't show up phenotypically.

Answer 1

Individuals with varying numbers of sex chromosomes present different phenotypes: XXY leads to a male phenotype with Klinefelter syndrome, XY results in a normal male, XXX leads to a female with Triplo-X syndrome and reduced fertility, and X0 results in a female phenotype with Turner syndrome.

Step-by-step explanation:

The question is about the phenotypic outcomes and peculiarities associated with certain genotypic configurations for sex chromosomes, and how these configurations might manifest. Considering the individuals described, here are the phenotypes and any notable genotypic characteristics:

• Individual 1 (XXY:AA) - Presents as a male with features of Klinefelter syndrome (typically with small testes, enlarged breasts, and reduced body hair). While the phenotype is male, the presence of an extra X chromosome is unusual.
• Individual 2 (XY:AA) - Represents a normal male phenotype with a typical genotype for sex determination.
• Individual 3 (XXX:AAA) - This individual is phenotypically female but may experience developmental delays and reduced fertility due to the triple X syndrome (Triplo-X).
• Individual 4 (X0:AA) - Presents with Turner syndrome, which is phenotypically female but is associated with a range of physical manifestations including short stature, neck webbing, and sterility.

Each of these genotypes reflects a deviation from the typical XX female or XY male chromosome pairings. Variation in the number of X chromosomes, as well as the presence or absence of the Y chromosome, can lead to diverse physical and reproductive phenotypes.