Biology 1002B Lecture Notes - Lecture 25: Chromosome, Alternative Lifestyle, Longwave
19 Apr 2016
School
Department
Course
Professor
Document Summary
Many animals have eyes, shown phylogenetic tree o. Eye has evolved independently at least 40 different times. Tissues recruited to make the eye very different. Harvest light, focus light, use light in fundamentally different ways o. Selected advantage: gained by ability to perceive external environment. Underlying difference in the types of tissues recruited. Crystallins: group of protein that form the lens of the eye. Kept clear because proteins are prevented from aggregated (clumping up) Pax6: family of highly related transcription factors o o. Switch on and off genes that are crucial in embryonic development o o o o. Essential to activating developmental pathway that leads to formation of the eye. Have major domains that are linked to function. Line up very well in different animals o. Cone cell: where colour vision comes from, photoreceptor cells o. Inside one cone cell many molecules of rhodopsin o. This is a cell like any other cell, but specialized cell.
