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50 Cards in this Set
- Front
- Back
What is Ecosystem
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sum total of all organisms and abiotic factors in a particular enviroment
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What is the portion of an ecosystem where a community could reside ?
An ecosystem contains many different __________ |
Habitat.
Also Habitat |
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What is the term for the total number of different species present?
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species richness
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What is the term for the proportion of each species in an ecosystem?
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species abundance
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Microbial species richness and abundance is dependant on .....
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the type and amount of nutrients available in a given habitat
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What is a guild?
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a group of microbial populations that has the same metabolic function
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Sets of guilds produce ____________ that interact with macroorganisms and abiotic factors in the ecosystem
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microbial communities
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What is a niche?
What does a niche supply the organisms |
A Habitat shared by a guild
supplies nutirents and conditions |
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The immediate enviromental surroundings of a microbial cell or groups of cells is called a _________________
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Microenvironment
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A grain of sand shows different niches. How ?
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each layer has a different niche because each has its own metabolic activity
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Why are surfaces important microbial habitats ?
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Nutrients adsorb to surfaces
Microbial cells can attach to surfaces |
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What are biofilms are where do they come from ? Why are they useful?
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an adhesive poly saccharide matrix that is used to enclose cells. Excreted by the cells
Biofilms trap nutrients for microbial growth and help prevent detachment of cells in flowing systems |
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What do cell in biofilms tend to be to each other
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symbionts
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The three steps for making a good biofilm ?
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Attachment - free floating usually motile cells go to a surface and attach to it. Their flagella falls off
Colonization - The polysaccharides matrix is formed, and their is intracellular communication growth. Development - the number of cells and polysaccharides film grows. Some cells slough off and become motile again when the bio film gets old. Holes made for water channels |
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Very thick biofilms that are visible to the eye are called what ?
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Microbial mats
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Microbial mats made by which bacteria. What do each contain
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Phototrophic and / or chemolithotrophic bacteria
Phototrophic - contain filamentous cynobacteria Chemolithotrophic - contain filamentous sulfur oxidizing bacteria |
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What is a Winogradsky column? What does it show ? Why are winogradsky columns considered stable ?
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Its a cross section of a microbial mat
cyno bacteria mat on the top, Purple is anoxygenic sulfur oxidizing bacteria the bottom is black , sulfur reducing They are very stable because the guilds are complementary to each other because one eats the products of the others and so on and so forth |
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What is the outer material on the earth's surface
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Soil
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What groups can soils be divided into? Describe each
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Mineral soils
Derived from rock weathering and other inorganic materials Organic soils Derived from sedimentation in bogs and marshes |
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Which horizon do decomposers love the most ?
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the O horizon
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Soils are composed of. From highest to lowest matter
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50% air and water
40% of inorganic soil volume 5% organic matter |
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Where does most microbial growth take place
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surface of soil particles
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What is the most important factor influencing microbial activity in surface soil
What is the most important factor for for subsurface enviroments? |
WATER
nutrients |
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how do microorganisms in the deep subsurface have access to nutrients ?
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because of groundwater flow
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What are oxygenic phototrophs suspended freely in water; include algae and cyanobacteria
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Phytoplankton
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What are attached to the bottom or sides of a lake or stream
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Benthic species
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What is a thermocline
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its where everything changes in a lake .
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How can fresh water rivers suffer oxygen deficiencies ?
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Organic matter from sewage
Agricultural and industrial pollution |
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Compared to fresh water, open ocean environment is?
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Saline
Low in nutrients, especially with respect to nitrogen, phosphorus, and iron Cooler |
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In order to survive the saline conditions, the bateria mus be
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Halo tolerant
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why do near shore marine waters typically contain higher microbial numbers?
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because nutrients are pushed to the shhore and stay there
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what are prochlorophytes?
Prochlorococcus accounts for how much the biomass of marine phototrophs and how much of the net primary production |
Most of the primary productivity in the open oceans is due to photosynthesis
40% of the biomass of marine phototrophs and 50% of the net primary production |
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The planktonic filamentous cyanobacterium ____________ is an abundant phototroph in tropical and subtropical oceans
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Trichodesmium <===adapted to high temperature
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Small phototrophic eukaryotes, such as ____________, inhabit coastal and marine waters and are likely important primary producers
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Ostreococcus
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What is abundant in pelagic marine waters?
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Small planktonic heterotrophic prokaryotes
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What densities of bacteria decrease with depth?
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Prokaryotic densities
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Why do densities decrease with depth?
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Less resources
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What type of organisms dominate the surface waters and which dominate the deeper waters?a
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Surface waters- bacterial species, Deeper waters- Archaeal species
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Why are archaea more abundant in deeper waters?
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They are more adapted
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What is an oligotroph?
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An organism that grows best at very low nutrient concentrations
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What is the most abundant marine heterotroph?
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Pelagibacter
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What is proteorhodopsin and what does it do?
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A form of rhodopsin that allows cells to use light energy to drive ATP sythesis
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Why are heterotrophs with proteorhodopsin not considered true phototrophs?
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Because it does not use photosystem one or two--> instead it uses sun directly
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What are the most abundant microorganisms in the oceans?
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Viruses
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What is biogeochemical cycling?
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The linked cycling of all nutrients in the environment (on Earth) and this includes both biogocial and chemical processes and are reducing and oxidizing at all times
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What kind of processes do aerobic carbon users do?
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Oxidizing
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What kind of processes do anaerobic carbon users do?
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Reducing
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How do acetogens make their food?
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Use H2 and CO2 to make acetate
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What do acetogens have to compete with for food?
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Methanogens
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What can fix nitrogen?
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ONLY bacteria
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