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The XY sex-determination systemis a sex-determination systempresent in many mammals, including humans, some insects (Drosophila), some snakes, some fish (guppies), and some plants (Ginkgotree). In this system, the sexof an individual usually is determined by a pair of sex chromosomes. Typically, females have two of the same kind of sex ...
Sexual dimorphism is a term for the phenotypic difference between males and females of the same species. The process of meiosis and fertilization (with rare exceptions) results in a zygote with either two X chromosomes (an XX female) or one X and one Y chromosome (an XY male) which then develops the typical female or male phenotype.
The XX/XY sex-determination system is the most familiar, as it is found in humans. The XX/XY system is found in most other mammals , as well as some insects. In this system, females have two of the same kind of sex chromosome (XX), while males have two distinct sex chromosomes (XY).
After examination, it was discovered that the difference between a typical XX individual (traditional female) and a sex-reversed XX man was that the typical individuals lacked the SRY gene. It is theorized that in sex-reversed XX men, the SRY mistakenly gets translocated to an X chromosome in the XX pair during meiosis. [8]
Sexual differentiation in humans is the process of development of sex differences in humans. It is defined as the development of phenotypic structures consequent to the action of hormones produced following gonadal determination. [1] Sexual differentiation includes development of different genitalia and the internal genital tracts and body hair ...
This is the condition of having any chromosome configurations rather than 46, XX or 46, XY intersex. This condition does not result in an imbalance between internal and external genitalia. However, there may be problems with sex hormone levels, overall sexual development, and altered numbers of sex chromosomes. [198]
The fundamental autosomal number or autosomal fundamental number, FNa[36]or AN,[37]of a karyotype is the number of visible major chromosomal arms per set of autosomes(non-sex-linked chromosomes). Ploidy. [edit] Ploidyis the number of complete sets of chromosomes in a cell. Polyploidy, where there are more than two sets of homologous chromosomes ...
Sex-chromosome dosage compensation. Dosage compensation is the process by which organisms equalize the expression of genes between members of different biological sexes. Across species, different sexes are often characterized by different types and numbers of sex chromosomes. In order to neutralize the large difference in gene dosage produced ...