Sex-determination systems

sex chromosome in the XY sex-determination system

sex chromosome present in both sexes, of species in which the male is the heterogametic sex

biological system that determines the development of organism’s sex

thumb|right|The coloration of tortoiseshell cats is a visible manifestation of X-inactivation. The black and orange [[alleles of a fur coloration gene reside on the X chromosome. For any given patch of fur, the inactivation of an X chromosome that carries one allele results in the fur color of the other, active allele.]] thumb|The process and possible outcomes of random X-chromosome inactivation in female human embryonic cells undergoing [[mitosis. 1.Early stage embryonic cell of a female human 2.Maternal X chromosome 3.Paternal X chromosome 4.Mitosis and random X-chromosome inactivation e

mammalian protein found in Homo sapiens

determination of an infant's sex at birth

chromosomal system that determines the sex of offspring in birds, some fish, some insects and crustaceans, and some reptiles

thumb |upright=2.0 |In the Hymenoptera, the [[sex-determination system involves haploid males and diploid females. System for honey bee shown.]]

method of determining sex

sex-determination system, with only 1 sex chromosome (“X”); males only have 1 X chromosome (X0); females have 2 (XX); found in most arachnids, many insects, some nematodes, some crustaceans, some molluscs, and some fish (e.g. Ancistrus)

the process of development of sex differences in humans

type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring

thumb|upright=2.0|Honey bees produce [[haploid males from unfertilized eggs]] Arrhenotoky (from Greek ἄρρην árrhēn "male" and τόκος tókos "birth"), also known as arrhenotokous parthenogenesis, is a form of parthenogenesis in which unfertilized eggs develop into males. In most cases, parthenogenesis produces exclusively female offspring, hence the distinction.

Xist (X-inactive specific transcript) is a non-coding RNA transcribed from the X chromosome of the placental mammals that acts as a major effector of the X-inactivation process. It is a component of the Xic – X-chromosome inactivation centre – along with two other RNA genes (Jpx and Ftx) and two protein genes (Tsx and Cnbp2).

Biological system in certain moths