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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 ...
Sex chromosomes (also referred to as allosomes, heterotypical chromosome, gonosomes, heterochromosomes, [ 1 ][ 2 ] or idiochromosomes[ 1 ]) are chromosomes that carry the genes that determine the sex of an individual. The human sex chromosomes are a typical pair of mammal allosomes. They differ from autosomes in form, size, and behavior.
The Y chromosome is one of two sex chromosomes in therian mammals and other organisms. Along with the X chromosome, it is part of the XY sex-determination system, in which the Y is the sex-determining chromosome because the presence of the Y chromosome causes offspring produced in sexual reproduction to be of male sex.
The human Y chromosome showing the SRY gene which codes for a protein regulating sexual differentiation. 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]
Sex differences in human physiology are distinctions of physiological characteristics associated with either male or female humans. These differences are caused by the effects of the different sex chromosome complement in males and females, and differential exposure to gonadal sex hormones during development. Sexual dimorphism is a term for the ...
The nematode C. elegans is male with one sex chromosome (X0); with a pair of chromosomes (XX) it is a hermaphrodite. [22] Its main sex gene is XOL, which encodes XOL-1 and also controls the expression of the genes TRA-2 and HER-1. These genes reduce male gene activation and increase it, respectively. [23]
The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body, and within the pelvis. The main male sex organs are the penis and the scrotum, which contains the testicles that produce semen and sperm, which, as part of sexual intercourse ...
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 ...