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Sex Linked Traits
I. Sex Chromosomes The sex chromosomes are the 23rd pair of chromosomes in Humans. Females have two X chromosomes (X X) Males have one X chromosome and one Y chromosomes (X Y) The X chromosome is considerably larger than the Y chromosome therefore there are many traits that are associated with the X chromosome; these are called sex-linked traits.
II Sex Linked Traits Color Blindness is an example of a sex linked trait. The gene for color blindness is found on the X chromosome. Females have two X chromosomes therefore they could have normal vision XX; Females could be a carrier for colorblindness (Xl X); or Females could be colorblind (Xl Xl ). Males can either have normal vision (X Y); or Males can be colorblind (Xl Y ). Since Males only have one X chromosome they cannot be a carrier; they will either have the trait, or not have the trait.
http://ghs.gresham.k12.or.us/science/ps/sci/soph/genetics/notes/sexlinked.htm http://web.mit.edu/esgbio/www/mg/sexlinkage.html http://www.biology.arizona.edu/mendelian_genetics/problem_sets/sex_linked_inheritance/07Q.html
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