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- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/09%3A_Mutation_and_Variation/9.08%3A_Linkage_and_Mapping/9.8.07%3A__Mapping_With_Three-Point_CrossesThis page discusses the three-point cross method for mapping three linked genes simultaneously. It involves crossing pure breeding lines to create a trihybrid and testcrossing to observe phenotypic di...This page discusses the three-point cross method for mapping three linked genes simultaneously. It involves crossing pure breeding lines to create a trihybrid and testcrossing to observe phenotypic distributions, allowing for the identification of rare double crossover events. The method aids in calculating recombination frequencies, correcting for undetected double crossovers, and improving genetic mapping accuracy.
- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/09%3A_Mutation_and_Variation/9.08%3A_Linkage_and_Mapping/9.8.01%3A__LinkageMendel’s Second Law does not apply to every pair of genes that could be studied. In fact, we now know that alleles of loci that are located close together on the same chromosome tend to be inherited ...Mendel’s Second Law does not apply to every pair of genes that could be studied. In fact, we now know that alleles of loci that are located close together on the same chromosome tend to be inherited together. This phenomenon is called linkage, and is a major exception to Mendel’s Second Law of Independent Assortment. Researchers use linkage to determine the location of genes along chromosomes in a process called genetic mapping and is important to natural processes of heredity and evolution.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/08%3A_The_Genetic_Consequences_of_Meiosis/8.08%3A_rII_Locus_of_T4This page discusses the T2 and T4 bacteriophages' role in genetic research on E. coli, highlighting Benzer's study of the rII gene, where he identified around 2000 point mutations. He determined that ...This page discusses the T2 and T4 bacteriophages' role in genetic research on E. coli, highlighting Benzer's study of the rII gene, where he identified around 2000 point mutations. He determined that the smallest mutation units are single base pairs and used deletion mutants for efficient mapping. Benzer's complementation tests revealed two complementation groups in rII, leading to the concept of cistrons as genetic functional units.
- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/09%3A_Mutation_and_Variation/9.08%3A_Linkage_and_MappingThis page discusses Mendel's Second Law of Independent Assortment, noting that while traits typically segregate independently, genes close together on a chromosome can exhibit linkage, which influence...This page discusses Mendel's Second Law of Independent Assortment, noting that while traits typically segregate independently, genes close together on a chromosome can exhibit linkage, which influences inheritance and genetic mapping. It explains that recombination through crossovers contributes to genetic diversity in meiosis, highlighting the importance of understanding linkage and recombination in heredity and evolution.
- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/05%3A_Genetic_Analysis_of_Multiple_GenesThe principles of genetic analysis that we have described for a single locus can be extended to the study of alleles at two loci simultaneously. Analysis of two loci in parallel is required for geneti...The principles of genetic analysis that we have described for a single locus can be extended to the study of alleles at two loci simultaneously. Analysis of two loci in parallel is required for genetic mapping and can also reveal gene interactions. These techniques are very useful for both basic and applied research. Before discussing these techniques, we will first revisit Mendel’s classical experiments.
