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dc.contributor.advisorKidwell, Margaret G.en_US
dc.contributor.authorLadin, Loren Guerrero, 1959-
dc.creatorLadin, Loren Guerrero, 1959-en_US
dc.date.accessioned2013-03-28T10:28:13Zen
dc.date.available2013-03-28T10:28:13Zen
dc.date.issued1989en_US
dc.identifier.urihttp://hdl.handle.net/10150/277085en
dc.description.abstractThe "DNA Damage Hypothesis" pertaining to the evolution of sex was tested using Hydra littoralis. DNA damage was produced by irradiating whole live hydra with ultraviolet light. A curve of uv light dosage vs. survival was constructed. Estimations of threshold fluence and LD50 were made from the survival curve. In four separate experiments, using various combinations of environmental temperatures, uv doses, and number of doses, frequencies of asexual and sexual reproduction were observed and compared. The hydra that received uv treatments did not show an increase in the consequent amount of sexual reproduction, and actually showed a decrease. An increase in the amount of sexual reproduction following DNA damage is predicted by the DNA damage hypothesis, therefore these results do not support this theory. The data was also used to make contradictory observations regarding the "stress hypothesis" for the occurrence of sexual reproduction in hydra.
dc.language.isoen_USen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectHydra -- Reproduction.en_US
dc.subjectUltraviolet radiation -- Physiological effect.en_US
dc.subjectDNA damage.en_US
dc.titleEffect of ultraviolet light on reproduction in Hydra littoralisen_US
dc.typetexten_US
dc.typeThesis-Reproduction (electronic)en_US
dc.identifier.oclc22905135en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.levelmastersen_US
dc.identifier.proquest1337967en_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineEcology & Evolutionary Biologyen_US
thesis.degree.nameM.S.en_US
dc.identifier.bibrecord.b17526267en_US
refterms.dateFOA2018-06-11T21:55:22Z
html.description.abstractThe "DNA Damage Hypothesis" pertaining to the evolution of sex was tested using Hydra littoralis. DNA damage was produced by irradiating whole live hydra with ultraviolet light. A curve of uv light dosage vs. survival was constructed. Estimations of threshold fluence and LD50 were made from the survival curve. In four separate experiments, using various combinations of environmental temperatures, uv doses, and number of doses, frequencies of asexual and sexual reproduction were observed and compared. The hydra that received uv treatments did not show an increase in the consequent amount of sexual reproduction, and actually showed a decrease. An increase in the amount of sexual reproduction following DNA damage is predicted by the DNA damage hypothesis, therefore these results do not support this theory. The data was also used to make contradictory observations regarding the "stress hypothesis" for the occurrence of sexual reproduction in hydra.


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