XYkromosoomi

XYkromosoomi refers to the pair of sex chromosomes that determine the male sex in humans and most other mammals. Typically, individuals with one X chromosome and one Y chromosome are phenotypically male. The X chromosome is larger and contains many more genes than the Y chromosome. The Y chromosome is crucial for male development, carrying the SRY gene (Sex-determining Region Y), which triggers the development of testes in an embryo. Without a Y chromosome, an individual typically develops female characteristics. The inheritance of sex chromosomes is a process of meiosis, where gametes (sperm and egg cells) are produced. Sperm carry either an X or a Y chromosome, while egg cells always carry an X chromosome. The combination of X from the egg and X from the sperm results in a female (XX), while the combination of X from the egg and Y from the sperm results in a male (XY). Variations in sex chromosome numbers can occur, leading to different genetic conditions. For instance, Klinefelter syndrome (XXY) affects males, while Turner syndrome (X) affects females. These variations highlight the complex interplay of chromosomes in sexual development.