AP Biology Sex Linked Traits
AP Biology Sex linked traits Genes are on sex chromosomes (pair 23) as opposed to autosomal chromosomes
AP Biology Genes on sex chromosomes Y chromosome few genes other than SRY SRY - Sex-determining Region of Y turns on genes for production of male hormones X chromosome other genes/traits beyond sex determination
AP Biology RRrr You would think this right? x rr R R Rr 100% red eyes Rr x Rr R r RR Rrrr Rr 3 red : 1 white Doesn’t work that way!
AP Biology XRXRXRXR XrYXrY But it’s not normal dominance…its sex- linked x XrXr Y XRXR 100% red eyes XRXR XRXrXRXr XRYXRY XRYXRYXRXrXRXr x XRXrXRXr XRYXRY XRXR Y XRXR XrXr XRXrXRXr XRYXRYXRXRXRXR XrYXrY 100% red females 50% red males; 50% white males
AP Biology Hemophilia Hh x HH XHYXHY XHXhXHXh XHXhXHXh XHXH XhXh XHYXHY Y XHXH sex-linked recessive XHXH Y male / sperm XHXH XhXh female / eggs XHXHXHXH XHXhXHXh XHYXHYXhYXhY XHXHXHXH XHYXHY XHXhXHXh XhYXhY carrierdisease
AP Biology Colorblindness Hh x HH XHYXHY XHXhXHXh sex-linked recessive XHXH Y male / sperm XHXH XhXh female / eggs XHXHXHXH XHXhXHXh XHYXHYXhYXhY XHXHXHXH XHYXHY XHXhXHXh XhYXhY carrierdisease
AP Biology What about Baldness? Great!!!! Any Questions?