III. Linkage A. ‘Complete’ Linkage B. ‘Incomplete’ Linkage OK… so we conclude the genes are linked… NOW WHAT?. AaBb x aabb. III. Linkage A. ‘Complete’ Linkage B. ‘Incomplete’ Linkage OK… so we conclude the genes are linked… NOW WHAT? - PowerPoint PPT Presentation
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III. Linkage
A. ‘Complete’ Linkage B. ‘Incomplete’ Linkage C. Three-point Mapping
I.Overview - Domains of LifeII. Prokaryotic Reproduction
A. fission
Bacterial Genetics
I.Overview - Domains of LifeII. Prokaryotic Reproduction
A. fission
= 10 billion cells
Bacterial Genetics
I.Overview - Domains of LifeII. Prokaryotic Reproduction
A. fissionThe rapid production of new
organisms creates genetic diversity by mutation, alone; even though the rates of mutation are low for any given gene.
Consider an average gene mutation rate = 1 x 10-5 (meaning a new mutation is produced in every 100,000 copies… or descendants).
In 10 billion (1010) descendants, there would be 105 different mutations at this one gene.
This is happening independently across 4000 (4 x 103) genes in the E. coli genome.
So, in that population of 10 billion cells, there might be as many as 4 x 108 different genomes. About 1/3 will be “silent” (not change the AA), and many will result in a lethal mutation so they won’t occur. But still….. VARIATION.
Bacterial Genetics
I.Overview - Domains of LifeII. Prokaryotic Reproduction
Figure 8-6And Cavalli Sforza isolated a strain that would cause genetic change at a very high rate: Hfr (High frequency recombination). He recognized that the acquisition of traits was related to the duration of the conjugation event.
Figure 8-8bHe isolated different strains that transferred genes in different order, suggesting that the transfer process could begin at different places.