BIO 325 Lecture Notes - Genetic Linkage, Genomic Imprinting, Mendelian Inheritance

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In cancer, it is seen that the maternal copy is silenced, so many issues arise. Chromosome mapping --- can determine their allelic position! Gives you the physical distance between genes. Genes assort independently if they are on different chromosomes but show linkage if they are on the same chromosome! If complete linkage exists between 2 genes because of their close proximity and organisms heterozygous at both loci are mated ---> unique f2 phenotypic ratio designated the linkage ratio results. Recombination - exchange of genetic information between linked genes of maternal and paternal alleles. Dependent on the distance between the 2 genes. If they"re close, then they"re going to stick together and rarely segregate. If they"re far apart, then many instances of crossing over can happen. Crossing over occurs ---> parents and recombinant (crossover) gametes. Interlocus distance - degree of crossing over between any two loci on a single chromosome is proportional to the distance between them.