sex chromosomes


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Related to sex chromosomes: DNA, Down syndrome, Multiple alleles

sex chro·mo·somes

the pair of chromosomes responsible for sex determination. In humans and most animals, the sex chromosomes are designated X and Y; females have two X chromosomes, males have one X and one Y chromosome In certain birds, insects, and fish the sex chromosomes are designated Z and W; males have two Z chromosomes, females may have one Z and one W chromosome, or one Z and no W chromosome.
Synonym(s): gonosome

sex chro·mo·somes

(seks krō'mŏ-sōmz)
The pair of chromosomes responsible for sex determination. In humans and most animals, the sex chromosomes are designated X and Y; females have two X chromosomes, males have one X and one Y chromosome.

sex chromosomes

The pair of chromosomes that determines gender. The other 22 pairs of chromosomes are known as autosomes. Women have two sex chromosomes of similar appearance called X chromosomes (XX). Men have one X chromosome and another, much smaller chromosome, called a Y (XY). Sperms have half the normal complement of chromosomes (haploid) and contain either an X or a Y. If an X chromosome effects fertilization the result will be a female, if a Y, a male.

sex chro·mo·somes

(seks krō'mŏ-sōmz)
The pair of chromosomes responsible for sex determination. In humans and most animals, the sex chromosomes are designated X and Y; females have two X chromosomes, males have one X and one Y chromosome.
References in periodicals archive ?
(6) It is now known that this test also has limitations, since other genes are also required for testis development and in addition, it has been reported that individuals with XX sex chromosomes, and therefore no SRY gene, can have testes.
TABLE 4-1 Karyotypes and gonadal sexes of various anomalies in human sexual differentiation Autosomes Sex Chromosomes Gonad Syndrome Name 44 X0 Ovaries Turner's 44 XX Ovaries Normal female 44 XXX Ovaries Superfemale 44 XY Testes Normal male 44 XXY Testes Klinfelter's 44 XYY Testes Supermale 66 XXX Ovaries Triploid (lethal) 66 XXY Testes Triploid (lethal) 44 [XX.sup.sxr] Testes Sex reversal (1) (1) In this case a small piece of the Y chromosome is translocated to an X chromosome.
A gradual process of recombination restriction in the evolutionary history of the sex chromosomes in dioecious plants.
The sex chromosomes cannot be distinguished by their differential pycnosis in somatic metaphases of males and females (Figs.
Gonadal sex is determined by the combination of sex chromosomes, unlike sex determination in the red-eared slider turtle (15).
At first metaphase the sex chromosomes form a trianglular figure, with the [X.sub.1] and [X.sub.2] centromeres pushing to the same pole and the Y to the opposite one.
Sex chromosomes are of two types called X (female) and Y (male).
Pholcus phalangioides (Fuesslin 1775) revealed 2n = 24 = 11II + [X.sub.1][X.sub.2] in males with metacentric autosomes and acrocentric sex chromosomes (Rodriguez-Gil et al.
The South American rodent Akodon azarae has a proportion of fertile females with sex chromosomes indistinguishable from the XY chromosomes of males, namely X[Y.sup.*] females (Bianchi and Contreras, 1967; Espinosa and Vitullo, 1996).
Like all other chromosomes, the X and Y sex chromosomes consists of strands of DNA along which are sited genes -- regions of DNA that provide the coded instructions for making proteins.
They're called the sex chromosomes and are markedly different from ordinary chromosomes.
Current thinking is that it may result from either sex chromosome mosaicism, the mutation of a gene involved in sex determination, or abnormal chromosomal translocation of the sex chromosomes.