- #1
TytoAlba95
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Why is the chance of crossing over between two closely placed genes is considered low compared to those that are distantly placed on a chromosome?
'The frequency of recombinants produced by crossing over is the key to chromosome
mapping. Fungal tetrad analysis has shown that, for any two specific linked
genes, crossovers take place between them in some, but not all, meiocytes
(Figure 4-7). The farther apart the genes are, the more likely that a crossover will
take place and the higher the proportion of recombinant products will be.
Thus, the
proportion of recombinants is a clue to the distance separating two gene loci on a
chromosome map.'
-An introduction to genetic analysis by Griffith
'The frequency of recombinants produced by crossing over is the key to chromosome
mapping. Fungal tetrad analysis has shown that, for any two specific linked
genes, crossovers take place between them in some, but not all, meiocytes
(Figure 4-7). The farther apart the genes are, the more likely that a crossover will
take place and the higher the proportion of recombinant products will be.
Thus, the
proportion of recombinants is a clue to the distance separating two gene loci on a
chromosome map.'
-An introduction to genetic analysis by Griffith