BIOLOGY – WHAT

BIOLOGY – WHAT - between the two will...

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BIOLOGY – WHAT - Multiply probability together to yield final - Epistasis, polygenic inheritence - Fruit files – wild-type has red eyes and long wings o Recessive mutations are given lower-case names o Wild-type alleles have a plus on them eg, pr + o th + would be a recessive allele o pr+pr vg+vg + prpr vgvg not crossed the way Mendel predicted. o In this case, purple eyes and vestigial wings must be linked (in cis) o By classifying the offspring we can infer the distribution of gametes and therefore the arrangement of genes and alleles on chromosomes. o The frequency of crossing over in meiosis can be a measure of the distance between genes o Map distance/centimorgans is defined as the percentage of recombinant progeny from a test cross. o Eg: total progeny 2839, total recominents 305, parentals 2534 305/2839 * 100 = 10.7% = 10.7 cM o Recombinant frequencies can be used to build genetic maps showing the relative location of genes on chromosomes. o As genes get further apart, the likelihood that recombination
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Unformatted text preview: between the two will occur, until they are so far apart that recombination event occurs every single time . When that happens, eg during cis, the mendellian rules apply and gametes are no longer disproportional and you cant tell if the genes are linked or not. o Any map distance larger than 50% means that you cant tell if theyre far apart or if theyre on different chromosomes. 10/50 * 100 0.10 recombinant from each, .10 times .10 = 0.1 -X and Y homologous, genes carried on the X but not the Y show non-mendeallian inheritance, X is larger than Y-Eg red vs white eyes in fruit flies sexed linked -X Chromosome is dominant pretty much always in males even if theyre recessive, not in females-Some insects have XX and X-Birds and shit WZ female, WW male-Bees are diploid or haploid-Some are temperature or frequency dependant....
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This note was uploaded on 10/23/2008 for the course BIO 1222 taught by Professor Maxwell during the Spring '08 term at UWO.

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