BIOL 1000 Lecture Notes - Lecture 2: Trichromacy, Dichromacy, Opsin
Document Summary
What is the molecular mechanism underlying the tri- vs dichromate vision: an individual containing only m & s opsins will have dichromatic vision, an individual containing s, m & l opsins will have trichromatic vision. The genetics of colour vision: the section of dna on a chromosome that codes for an opsin protein is called an opsin gene. Location of opsin genes: gene coding for opsin protein s is located on chromosome 7 (seven, gene coding for m & l are located on the x chromosome. 1: duplication of m opsin on x chromosome. Duplication: a duplicated segment is inserted into a homologous chromosome. Gene mutation of the duplicated m gene on the x chromosome turn m gene into l. Females of two x chromosomes which gives females a lesser chance of missing an l opsin whereas men have only one x chromosome so they are more likely to miss an l opsin.
