ISB 202 Exam 2 Review

ISB 202 Exam 2 Review - ISB 202 Exam 2 Review Species...

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ISB 202 Exam 2 Review Species Interaction Species interactions are the backbone of communities Natural species interactions o Competition—both species are harmed o Exploitative—one species benefits and the other is harmed Predation—process by which individuals of one species (predators) capture, kill, and consume individuals of another species (prey). Structures food webs and the number of predators and prey influences community composition Zebra mussels eat phytoplankton and zooplankton—both populations decrease in lake with zebra mussels Zebra mussels don’t eat cyanobacteria—pop increases in lake with zebra mussels Parasitism—a relationship in which one organism depends on another for nourishment or other benefit. The parasite harms but doesn’t kill the host Some are free living—infrequent contact with their hosts (ticks and sea lampreys) Some live within the host (disease, tapeworms) Parasitoids=insects that parasitize other insects killing the host Coevolution=hosts and parasites become locked in a duel of escalation adaptions—has been called an evolutionary arms race o Each evolves new responses to each other and it may not be beneficial to the parasite to kill the host Herbivory—animals feed on the tissues of plants (widely seen in insects). This may not kill the plant but affects if growth and survival o Mutualism—both species benefit Symbiosis=mutualism in which the organisms live in close physical contact—each species provides service for the other Pollination=in exchange for a plants nectar, the animals pollenate plants, which allows them to reproduce Bees, bats, birds, and other transfer pollen form one flower to another, fertilizing its eggs o Amensalism=one organism is harmed while the other is unaffected Difficult to confirm, bc usually one organism benefits from harming the other Allelopathy—certain plants release harmful chemicals o Commensalism=one org benefits, other is unaffected
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Competition Competition—multiple organism seek the same limited resources like food space water shelter mates sunlight Intraspecific competition—between members of the same species o High population density=increased competition o Results Competitive exclusion=one species completely excludes another species form using the resource (zebra mussels displaced native mussels in the great lakes) Species coexistence=neither species fully excludes the other from resources, so both live side by side (this creates stable point of equilibrium with stable pop sizes) Species minimize competition by using only a part of the available resource (niche) Interspecific competition—between members of 2 o more species o Strongly affects community composition o Leads to competitive exclusion or species coexistence Niche: and individuals ecological role o Fundamental niche—the full niche of a species o Realized niche—the portion of the fundamental niche that is actually filled
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This note was uploaded on 04/02/2012 for the course ISB 202 taught by Professor Johnson during the Winter '08 term at Michigan State University.

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ISB 202 Exam 2 Review - ISB 202 Exam 2 Review Species...

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