Search results
Results From The WOW.Com Content Network
In the XY sex-determination system, the female-provided ovum contributes an X chromosome and the male-provided sperm contributes either an X chromosome or a Y chromosome, resulting in female (XX) or male (XY) offspring, respectively. Hormone levels in the male parent affect the sex ratio of sperm in humans. [25]
Two use homomorphic male heterogamety, one uses XX/XY, one uses ZZ/ZW. Remarkably, the X and Z chromosomes are homologous, and the Y and W as well. Dmrt1 is on autosome 1 and not sex-linked. This means that an XX female individual is genetically similar to a ZZ male individual, and an XY male individual is to a ZW female individual.
46,XX/46,XY chimeric or mosaic is associated with a wide spectrum of different physical presentations, with cases ranging from having a completely normal male or female phenotype [7] [8] [9] to some cases having ovotesticular syndrome. Due to this variation, genetic testing is the only way to reliably make a diagnosis.
Individuals can either have sex chromosomes generally linked with being female (XX chromosomes) or usually associated with being a man (XY chromosomes), yet have reproductive organs and genitals ...
In the absence of a Y chromosome, the fetus will undergo female development. This is because of the presence of the sex-determining region of the Y chromosome, also known as the SRY gene. [5] Thus, male mammals typically have an X and a Y chromosome (XY), while female mammals typically have two X chromosomes (XX).
XX males that are SRY-positive have two X chromosomes, with one of them containing genetic material (the SRY gene) from the Y chromosome; this gene causes them to develop a male phenotype despite having chromosomes more typical of females. [2] Some XX males, however, do not have the SRY gene (SRY-negative); the reason a male phenotype develops ...
The common pathway of sexual differentiation, where a productive human female has an XX chromosome pair, and a productive male has an XY pair, is relevant to the development of intersex conditions. During fertilization, the sperm adds either an X (female) or a Y (male) chromosome to the X in the ovum. This determines the genetic sex of the embryo.
Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Females typically have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY). 48,XXYY syndrome results from the presence of an extra copy of both ...