PLPA 200 Lecture Notes - Lecture 5: Ultraviolet, Saprotrophic Nutrition, Desiccation

• School: University of Illinois
• Department: Plant Pathology
• Course: PLPA 200
• Professor: Eastburn Darin

Document Summary

The major concept for this week is the bacteria. First, bacteria are tiny, single-celled organisms, in contrast to fungi, plants and animals, which are all multicellular. A single bacterium is smaller than the spores produced by fungi. Each bacterium is prokaryotic, meaning that its genetic material is not contained within a membrane- bound nucleus. Rather, the genetic material is a single dna chromosome that is tangled within an area of the cell called a nucleoid. This feature also distinguishes bacteria from fungi, plants and animals, which are all eukaryotic organisms with genetic material contained within the nuclei of their cells. Like plants and fungi, most bacteria have cell walls that determine their shape. Most plant pathogenic bacteria are rod-shaped or bacilliform. A few specialized plant pathogenic bacteria lack cell walls and can be variable in shape or partially helical. Most plant pathogenic bacteria have agella, external structures that rotate to propel the cells short distances through liquids.