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51 Cards in this Set
- Front
- Back
What are some plant adaptations to avoid herbivory?
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- Toxicity
- Thorns - Tough outer layer - Stickiness - Height - Colouration |
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What are Carnivorous plants?
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Example of predatory plants
- PS'tic but obtain nutrients by killing and digesting insects |
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Define symbiosis and give some examples
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A relationship where 2 or more species live in direct and intimate contact with one another
- Parasitism - Mutualism - Commensalism |
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What is parasitism?
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(+/- interaction)
- the parasite derives nourishment from the host which is harmed in the process |
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What is the difference between endoparasites and ectoparasites?
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Endo - live within the body of their host
Ecto - parasites that live on the external surface of the host |
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What are parasitic plants?
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- Absorb sugars and minerals from their living host plant
ex: mistletoe, ectoparasite |
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Define mutualism
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(+/+ interaction)
An interaction that benefits both species |
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What is the difference between obligate and facultative mutualism?
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Obligate: One species cannot survive without the other
Facultative: Both species can survive alone |
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What is the rhizosphere?
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The layer of soil bound to the plant's roots
- Has high microbial activity b/c sugars, amino and organic acids secreted by the roots |
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Where do the rhizobacteria thrive?
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In the rhizosphere
- Some enter roots |
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What roles do rhizobacteria play?
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- Produce hormones that stimulate plant growth
- Produce antibiotics that protect roots from disease - Absorb toxic metals or make nutrients more available to roots |
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What is N fixation?
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The conversion of Nitrogen from N2 to NH3
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What are nodules?
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On legumes roots
- plant cells "infected" by N2-fixing rhizobium bacteria |
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What is the mutualism between fungi and plants?
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- Mycorrhizae
- Fungus benefits from sugar from the host plant - Host plant gets increased water uptake and mineral absorption |
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What is the difference between ectomycorrhizae and arbuscular mycorrhizae?
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Ecto: mycelium do not penetrate plant root cells
Arbuscular: fungal hyphae extend into the root - penetrate cell wall but not plasma mb |
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What is commensalism?
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(+/0 interaction)
- One species benefits and the other is apparently unaffected |
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What is trophic structure?
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The feeding relationships b/w organisms in a community
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What are food chains?
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Link trophic levels from producers to top carivores
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What is a food web?
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A branching food chain with complex trophic interactions
- Sp may play a role at more than one trophic level |
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What is the microbial food web?
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Aquatic ecosystems have a separate "microbial food web"
bacteria-->flagellates-->ciliates |
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What is an ecosystem?
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The community of organisms and the physical factors within which they interact
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What does ecosystem ecology emphasize?
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E flow and chemical cycling among biotic and abiotic components
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Define landscape
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A mosaic of connected ecosystems
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Define landscape ecology
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Deals with multiple ecosystems and how they are arranged in a geographic region
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What is the biosphere?
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The global ecosystem - the sum of all of the planet's ecosystems
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What is global ecology?
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Examines the influence of E and materials on organisms across the biosphere
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How does E enter ecosystems?
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Enters as solar radiation, is transferred and is lost from organisms as heat = E flows
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What is primary production?
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The amount of light E converted to chem E by autotrophs
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What is secondary production?
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The amount of chem E in food that is converted to new biomass
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What is an organisms production efficiency?
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The fraction of E stored in food that is not used for respiration or waste
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What is trophic efficiency?
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The percentage of production transferred from one trophic level to the next
- usually ranges from 5-20% -avg 10% - Multiplied over length of food chain |
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How much of chem E reaches tertiary consumers
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0.1% of chem E fixed by PS reaches a tertiary consumer
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What is the law of conservation of mass?
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Matter cannot be created nor destroyed
- Chem elements are continually recycled within ecosystems = mass is cycled |
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What are biogeochemical cycles?
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- Nutrient cycling includes reservoirs of elements and processes that transfer elements between reservoirs
- Nutrient circuits in ecosystems involve biotic and abiotic components - Disruptions in biogeochemical cycles result in most of our env'al problems |
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What does agriculture do?
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Depletes the mineral content of the soil, taxes water reserves and encourages erosion
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What is the goal of sustainable agriculture
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To use farming methods that are conservation-minded, environmentally safe, and profitable
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What are pools and processes in the water cycle?
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Pools: 97% ocean, 2% glaciers, 1% lakes and ground water
Processes: evap and precip, run off and ground water flow and return water to the oceans |
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What is the primary source of irrigation water?
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Underground water reserves called aquifers
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What can the depletion of aquifers lead to?
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Subsidence - the settling or sinking of land
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What can irrigation lead to?
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Salinization - the [ ] of salts in soil as the water evaporates
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What are the pools and processes of the nitrogen cycle?
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Pools: Atmosphere (N2 gas) - unavailable
- Biomass, dissolved in water, soils - available Processes: N2 fixation (bacteria) - Assimilation, excretion |
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How do plants absorb N?
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As either NO3- or NH4+
- Bacteria produce NH3 which is converted to NH4+ |
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What do both bacteria and lightening do to N?
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Move inorganic unavailable N (N2) to inorganic available N (NH4+, NO3-)
(Now we have industrial N-fixation to increase availability) |
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What does fertilization do?
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Replaces mineral nutrients that have been lost from the soil
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What are C reservoirs?
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Fossil fuels, soils and sediments, solutes in the ocean, biomass, the atmosphere
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How does C move between reservoirs?
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PS and respiration
- Burning of fossil fuels adds CO2 to atmosphere |
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What are options to remove C from atmosphere?
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- Increase forests
- Increasing productive, shallow ponds |
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How are coral reefs formed?
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From the calcium carbonate skeletons of corals
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What mutualistic relationship is there with coral?
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Unicellular algae live within tissue of the corals and form mutualistic relationships
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What causes coral bleaching?
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Increased temp, increased UV exposure, ocean acidification
- Viruses (herpes) |
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What is the tropical rainforest?
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Warm temp, constant precip year-round
- Intense competition for sunlight and nutrients |