5細(xì)菌的遺傳和變異e(編輯修改稿)
2024-10-04 04:45 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 scriminate use of antibiotics have provided a selective advantage for bacteria harboring these plasmids. 第九頁(yè)，共四十二頁(yè)。 第十頁(yè)，共四十二頁(yè)。 Mechanism of bacterial variation ? Gene mutation ? Gene transfer and rebination ? Transformation ? Conjugation ? Transduction ? Lysogenic conversion ? Protoplast fusion 第十一頁(yè)，共四十二頁(yè)。 Types of mutation ? Base substitution ? Frame shefit ? Insertion sequences 第十二頁(yè)，共四十二頁(yè)。 What can cause mutation? ? Chemicals: nitrous acid。 alkylating agents 5bromouracil benzpyrene ? Radiation: Xrays and Ultraviolet light ? Viruses 第十三頁(yè)，共四十二頁(yè)。 Bacterial mutation ? Mutation rate ? Mutation and selectivity ? Backward mutation 第十四頁(yè)，共四十二頁(yè)。 Transformation ? Transformation is gene transfer resulting from the uptake by a recipient cell of naked DNA from a donor cell. Certain bacteria (. Bacillus, Haemophilus, Neisseria, Pneumococcus) can take up DNA from the environment and the DNA that is taken up can be incorporated into the recipient39。s chromosome. 第十五頁(yè)，共四十二頁(yè)。 第十六頁(yè)，共四十二頁(yè)。 第十七頁(yè)，共四十二頁(yè)。 第十八頁(yè)，共四十二頁(yè)。 第十九頁(yè)，共四十二頁(yè)。 第二十頁(yè)，共四十二頁(yè)。 Conjugation ? Transfer of DNA from a donor to a recipient by direct physical contact between the cells. In bacteria there are two mating types a donor (male) and a recipient (female) and the direction of transfer of geic material is one way。 DNA is transferred from a donor to a recipient. 第二十一頁(yè)，共四十二頁(yè)。 Physiological States of F Factor ? Autonomous (F+) – Characteristics of F+ x F crosses ?F bees F+ while F+ remains F+ ?Low transfer of donor chromosomal genes F+ 第二十二頁(yè)，共四十二頁(yè)。 Physiological States of F Factor ? Integrated (Hfr) – Characteristics of Hfr x F cros
外語(yǔ)相關(guān)推薦
鄂ICP備17016276號(hào)-1