Review for Exam II Spring 08

Review for Exam II Spring 08 - EXAM II REVIEW CHAPTER 27 1....

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EXAM II REVIEW CHAPTER 27 1. Prokaryotes-  2. Symbiosis- ecological relationship between organisms of different species that are in  direct contact. 3. Mutualism- both symbiotic organisms benefit. 4. Commensalism- one organism benefits while neither hurting nor helping the other  organism. 5. Parasitism- parasite benefits at the expense of the host. 6. Coccus-  spherical, occur singly, in pairs, in chains and in clusters. 7. Bacillus- rod-shaped, usually solitary, sometimes rods are arranged in chains. 8. Helix (Spirochete)- spiral 9. Peptidoglycan- in most bacterial cell walls. Network of modified- sugar polymers cross  linked by short polypeptides. Encloses entire bacteria and anchors it to other molecules. 10. Gram Positive- simpler walls with a large amount of peptoglycan. 11. Gram Negative- less peptiglycan and structurally more complex with an outer membrane  that contains lipopolysaccharides (often toxic) sometimes protect bacteria from the  body’s defense.  12. Gram-neg are more threatening than gram-pos  because of the liposaccharide layer on  the gram-neg cell wall. Outer membrane protects the bacteria from the body’s defense  system. Gram-neg are more resistant to antibiotics because the outer membrane  impedes the entry of drugs. 13. Antibiotics-  14. Capsule- covers the cell wall of many prokaryotes; it’s a sticky layer of polysaccharide or  protein. Enables prokaryotes to adhere to their substrate or to other individuals in a  colony. Also shield pathogenic prokaryotes from attacks from host’s immune system. 15. Pilus (pili)- a long hair like prokaryotic appendage that functions in adherence or in  transfer of DNA during conjugation. Like bacteria during conjugation. 16. Cell wall-  17. Lipopolysaccharides- carbonhydrates bonded to lipids 18. Taxis- movement toward or away from a stimulus. 19. Chemotaxis- respond to chemicals by changing their movement patterns a. Positive chemotaxis- move toward nutrients/oxygen b. Negative chemotaxis- move away from toxic substance 20. Phototaxis- 
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21. Nucleoid region- contains prokaryotic chromosome, a part of the cytoplasm that appears  lighter than the surrounding cytoplasm. 22. Plasmids- in addition to a single chromosome, a typical prokaryote have smaller rings of  DNA called plasmids which consist of only a few genes. 23. Binary Fission-  24. Transformation-  25. Conjugation- direct transfer of DNA between two cells that are temporarily joined. 26.
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This note was uploaded on 06/28/2008 for the course BIOL 112 taught by Professor Vaughn during the Spring '08 term at Texas A&M.

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Review for Exam II Spring 08 - EXAM II REVIEW CHAPTER 27 1....

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