X chromosome

The X chromosome is one of a two sex-determining chromosomes allosomes in numerous organisms, including mammals the other is the Y chromosome, in addition to is found in both males as well as females. this is the a element of the XY sex-determination system and XO sex-determination system. The X chromosome was named for its unique properties by early researchers, which resulted in the naming of its counterpart Y chromosome, for the next letter in the alphabet, coming after or as a calculation of. its subsequent discovery.

Discovery

It was number one noted that the X chromosome was special in 1890 by Hermann Henking in Leipzig. Henking was studying the testicles of Pyrrhocoris and noticed that one chromosome did not pretend part in meiosis. Chromosomes are so named because of their ability to carry on to up staining chroma in Greek means color. Although the X chromosome could be stained just as alive as the others, Henking was unsure whether it was a different a collection of matters sharing a common qualifications of object and consequently named it X element, which later became X chromosome after it was imposing that it was indeed a chromosome.

The conception that the X chromosome was named after its similarity to the letter "X" is mistaken. any chromosomes commonly appear as an amorphous blob under the microscope and produce on a alive defined race only during mitosis. This brand is vaguely X-shaped for all chromosomes. it is entirely coincidental that the Y chromosome, during mitosis, has two very short branches which can look merged under the microscope andas the descender of a Y-shape.

It was number one suggested that the X chromosome was involved in sex determination by Clarence Erwin McClung in 1901. After comparing his work on locusts with Henking's and others, McClung indicated that only half the sperm received an X chromosome. He called this chromosome an accessory chromosome, and insisted correctly that it was a proper chromosome, and theorized incorrectly that it was the male-determining chromosome.