Bio%20201%20S12%20Lect%2018%20%28True%29%20v2

35 mulaple choice quesaons 3 bonus factoid

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Unformatted text preview: amer exam starts ONLY DOCUMENTED MEDICAL/FAMILY BEREAVEMENT EMERGENCIES ARE ACCEPTABLE EXCUSES FOR MISSING EXAM –  no other excuses accepted PracAce quesAon set will be posted on BB TA review session Ames will be posted on BB mid- semester evaluaAons •  you should all have received an e- mail about these –  at your BB/Solar associated e- mail •  please fill them out (on Prof. True) Back to Herbivory Herbivory •  Similar to predaAon – a factor affecAng populaAon persistence, community composiAon •  Herbivores consume or destroy ~18% of terrestrial plant biomass >50% in aquaAc systems Measuring Effects of Herbivory •  Study herbivores and plants in field •  Removal experiments Measuring effects of herbivores on plants in field •  In 93 published studies, average of 7% of leaf area eaten •  Temperate forest systems = 5 - 15% defoliaAon by insects –  Ex. Gypsy moth •  naAve of Eurasia, introduced accidentally in N. America in 1800s Gypsy moth (Lymantria dispar) defoliaAon Which type of plants are most affected? •  Herbivore effects: –  greatest on algae –  smallest on woody plants Chemical Defenses Secondary chemicals = Defense compounds –  Not part of primary metabolic pathways that plants use to obtain energy Example of plant chemical defenses –  Alkaloids –  Mustard oils Milkweed – var. alkaloids hemlock alkaloid -coniine Jimsonweed - alkaloids Oleander – glycoside oleandrin Locoweed neurotoxin swansonine Mechanical defenses •  Thorns and spines deter vertebrate herbivores –  In open sites, plants close to ground, tasty –  Plants like palms, 1 meristem –  Evergreens in a deciduous forest - severe herbivore pressure in the winter ConsideraAons from the real world (i.e. more complicated than two species of mites on an array of oranges) -   Predator abundance won’t always determine prey abundance -   Predators omen take the weak individuals hRp://www- tc.pbs.org/wnet/nature/files/2010/11/2805- photogallery- 11- 610x403.jpg predaAon is a strong selecAon pressure •  one of the most obvious adaptaAons: coloraAon •  e.g. mimicry –  Batesian: tasty mimic, unpalatable model –  Mullerian: several unpalatable species converge on the same color paRern Antipredator Adaptations •  Aposematic or warning coloration –  Advertises an...
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This note was uploaded on 10/02/2013 for the course BIO 201 taught by Professor True during the Spring '08 term at SUNY Stony Brook.

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