The Effects of Temperature on Crossing Over Frequency

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According to the results obtained in the laboratory exercise, it appears that the gene to centromere distance tends to vary at different temperatures, as well as with different environmental conditions. At different environmental conditions, variations in recombination frequencies are found in Sordaria . Recombination generates new combinations of existing genetic variation and therefore may be important in adaptation and evolution ( Saleem2001). Throughout the years it has been observe how different species have adapt to different environmental conditions, and because of the new spices have evolve. A variable recombination frequency dependant on environmental conditions can provide to an organism the ability to survive at different temperatures or different environmental conditions.

In addition variable recombination frequencies at different environmental conditions can ensure genetic variation as well. When observing the results from different crosses it can be observe how temperature influences the behavior of the organisms. The results are due to the effects of temperature upon crossing-over and that chiasma interference in conjunction with differences in chromosome structure may account for the three varied patterns of segregation. (Olive 1956).This paper discusses and investigates, whether there was natural genetic variation for recombination frequencies and whether any such variation was environment related and possibly adaptive (Salem2001). In the results obtained from the lab it can be observe, how the numbers in percent crossing over varies between crosses as well as in different environmental conditions. In graphs 1 and 2 it can be observe how the percent of crossing over is higher in the cultures incubated at ...

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...he percent of crossing over at different temperatures, temperature govern chiasma frequency by interference (Olive 1956). One thing can be consider, temperature plays a very important role in crossing over frequency. Finally, temperature affects crossing over by increasing or decreasing the percent of crossing over in each of the Sordaria crosses.

Works Cited

B. C. LAMB, Related and unrelated changes in conversion and recombination frequencies with temparature in Sordaria (1968)

Lindsay S. Olive. Genetics of Sordaria fimicola. I. Ascospore Color Mutants (1956)

Muhammad Saleem ,Bernard C. Lamb ,and Eviatar Nevo, Inherited Differences in Crossing Over and Gene Conversion Frequencies Between Wild Strains of Sordaria fimicola From "Evolution Canyon" (2001)

AGNES M. TOWE AND D. R. STADLER, Effects of temperature on crossing over in Neurospora , (1963)

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