Sex+determination+in+various+animals

by seth and devin

What sex determination is, and how it works. Sex determination is a biological system that determines the development of the sexual characteristics of the organisms. Most of the sexual organisms have two different pairs of alleles as in a male and a female, but there is some case were the environment (such as temperature) actual determines the sex of the organisms or the size of the relatives. Some sex determination of animals are still unknown like the fish it spends half his life as a female than turns into a male. The XX/XY is the most familiar sex determination system it’s found in human most mammals even some insects as in (drosphila) and some plants (Ginkgo). However the platypus has it’s sex traits as ZW the same as a bird it also lacks the SRY gene. It has ten sex chromosomes; males have XYXYXYXYXY while the females are 10 X. In the xy sex-determination females have the same letter(XX) while males have to distant (XY) have a SRY on the y chromosomes that determines male others such as ( fruit fly’s) use the presence of two X chromosomes to determine female. As for grass hopers crickets and cockroaches the sex traits are XX and XO. Females have the XX chromosomes so the can give off only two XX as like humans. Males on the other hand are an XO so they can give off either the X or the O to determine the sex of the spouse. The bird on the other hand the female has the ZW instead of the ZZ and the male has the same trait (ZZ) instead of two different ones (ZW) so that would mean that the female would determine the sex of the spouse which would be very original to the other species which the males determine the sex of the spouse. Did you know that bees haplodiploidy which means that the queen bee with one drone the spouse share ¾ of the genes instead of ½ like any normal organisms. There are also some reptiles that don’t get a sex when there born like alligators and some turtles. Therese also some that are located in the tropical ocean do you now what they are? If you guessed clown fish you are rite so once they hit middle age they turn sexes like male to female so think about it one day your sitting at the tabor with your friends the next your cleaning and cooking scary right. In most mammals the males carry the main determining sex gene, SRY; it is located on the Y chromosome. It is absent to XX of the females. The SRY is specific in mammals. In some fish it involves simple male heterogamety. The difference in humans is that the Y chromosome is similar to the X chromosome. There is no difference in X and Y, X-Y pairing occurs along the length of the chromosome. The male determining region in the Y chromosome is relatively small. The sex determining chromosome in birds is ZZ for males and ZW for females. However recent discovery has discovered that the Z-1 gene, which is maintained across phyla as a gene involved in sexual differentiation, it is expressed in early male development. This suggests that that it might be the number of Z chromosomes that regulate the sex in birds. However the recent identification of the first protein, which is unique in female birds, was encoded by the W-linked gene. The observation in early female gonads shows that the W chromosome plays a role in avian sex determination. 

Links To Further Understanding

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Rebecca Pulse-Learn about Anthias, how they change sex, and how to care for them: [] Rebecca Pulse- More information on Clownfish and the way they live: [] Tyler Decker- Information on sex determintation in amphibians: [] Tyler Decker- Information on sex determination in plants: []