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Bio Exam 2 Study Practice Objectives

Terms in this set (41)

In Module 2 Class 2

water - starts in atmospheric level and is then precipitated down , kept above ground in lakes , stored in plants , drunk by animals . but some is absorbed and used as ground water . the water is then used biologically and disposed of . the water evaporates , condenses , and is precipitated down again in a lesser amount (mostly)

carbon - found in all organisms (building block of cells and life) where pollution , terrestrial photosynthesis , emissions from burning fossil fuels , weathering of rocks and more processes dispose of carbon dioxide in the atmosphere . carbon also is kept in the ground (decomposition of organisms and weathering) as soil carbon which can stay in the ground as fossil carbons , transformed by microbial respiration (or taken as humans for energy) , and composed into run-off

nitrogen - biologically done through the 3 processes of (1) ammonification , (2) nitrification , and (3) denitrification .1) nitrogenous waste is converted from dead animals into ammonium2) nitrifying bacteria converts ammonium into nitrites , and then again into nitrates3) bacteria convert the nitrates into nitrogen gas which is released back into the atmospherecycle : nitrogen fixing bacteria take nitrogen (N2) from the air an into ecosystems , then when animals die and decompose the necessary process (1 , 2 , 3) occur which release the nitrogen back into the environment . simultaneously , humans use nitrogen in fertilizers that are run off into marine and aquatic ecosystems . the nitrogen in the marine food webs are processed (2 , 3) to be released back into the atmosphere , but some lies as sediment on the bottom of these ecosystems

phosphorous - weathering can erode phosphates found in minerals , releasing it into the environment (or as aerosol in the air) where its run off and deposited as sediment in marine ecosystems and geologically uplifted . also , phosphorous is used as fertilizers for human development , and is run off into marine ecosystems and present in agricultural cycling
Commensalism: A commensal relationship occurs when one species benefits (+) from the close, prolonged interaction, while the other species neither benefits nor is harmed (0) Birds nesting in trees provide an example of a commensal relationship. The tree is not harmed by the presence of the nest among its branches. The bird, on the other hand, benefits greatly.
Mutualism: where two species benefit from their interaction (+,+). For example, termites have a mutualistic relationship with protozoa that live in the insect's gut . The termite benefits from the ability of bacterial mutualists within the protozoa to digest cellulose. The protozoa and their mutualistic bacteria benefit by having a protective environment and a constant supply of food from the wood chewing actions of the termite.
Parasitism: A parasite is an organism that lives in or on another living organism and derives nutrients from it. In this relationship, the parasite benefits (+), but the host (who is being fed upon) is harmed (-). The host is usually weakened by the parasite as it siphons resources. The parasite, however, is unlikely to kill the host, especially not quickly, because this would allow no time for the parasite to complete its reproductive cycle by spreading to another host.
Amensalism: any interaction between individuals of different species in which one individual is harmed (-) while the other individual is not affected (0). For example, as you walk down a sidewalk on a rainy day, you step on an earthworm. The earthworm is negatively affected, and you are not affected at all