Introduction to Genetic Analysis 110

Introduction to Genetic Analysis 110 - 44200_03_p73-114...

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109 Problems mitosis reproduces genetically identical genotypes. Like- wise, all nuclei in every male gametophyte will be a .In the corn life cycle, the endosperm is formed from two female nuclei plus one male nucleus, so two endosperm types will be formed as follows: / polar 3 n / spore nuclei ? sperm endosperm AA and Aa A / A / a aa and a / a / a Second cross: a / a / 3 A / a ? / polar 3 n / spore nuclei ? sperm endosperm All a All a and aA A / a / a / a/a The phenotypic ratio of endosperm characters would still be Mendelian, even though the underlying en- dosperm genotypes are slightly different. (However, none of these problems arise in embryo characters, be- cause embryos are diploid.) b. This kind of experiment has been very useful in studying plant genetics and molecular biology. In an- swering the question, all we need to realize is that the two polar nuclei contributing to the endosperm are ge- netically identical. To obtain endosperms, all of which will be a / a / a , any a / a 3 a / a cross will work. To obtain endosperms, all of which will be
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This note was uploaded on 01/10/2011 for the course BIOL BIOL taught by Professor Johnson during the Spring '08 term at Aberystwyth University.

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