ch 30 flashcards.txt

  1. Carbon cycle
    decomposers make CO2 and this is also produced from d�gradation of organic material. Producers use CO2 and convert it into organic products. These producers are eaten by the 1 consumers, which aquire this carbon for energy and biomass, then 2 consumers eat 1, and so on, until decomposers are used
  2. Nitrogen cycle
    • Nitrogen fixation involves nitrogen being �fixed into its ORGANIC nitrogen
    • Ammonification is done by nitrogen being taken up by plants to form NH3
    • Nitrification oxidizes ammonia to NO2 and NO3, where plants take it up or..
    • Denitrification occurs, where NO3 is turned back into N (by anaerobic bacteria).
  3. Sulfur cycle
    Sulfur Oxidation : H2S oxidized through Sulfur bacteria (oxidized anaerobically by blue and purple sulfur bacteria), then Sulfur is oxidized to Sulfate, which can be REDUCED or incorporated into plants, which REDUCE it back to hydrogen sulfide (H2S)
  4. Differentiate among nitrification, denitrification and ammonification.
    • Ammonification converts ORGANIC nitrogen INTO Ammonia
    • Nitrification OXIDIZES Ammonium INTO Nitrate
    • Denitrification Converts Nitrate INTO gaseous NITROGEN � contributes to global warming, bad for farmers as Nitrogen released into air instead of for plants
  5. Describe nitrogen fixation and explain its importance.
    It is used to produce ammonia from Nitrogen gas through Reduction. This is done by prokaryotes, which animals rely on to turn this into ammonia so it can be incorporated into cellular material and used for biomass
  6. Describe the relationship between microorganisms and herbivores.
    Microorganisms are found in the earth as many different things, but to relate them to herbivores we are talking about those microorgs which live inside the DIGESTIVE tract of herbivores. These microbes living in there digest CELLULOSE and HEMIcellulose, which are used to provide nutrients to the animal.
  7. Microorganisms and Eukaryotes:
    Endomycorrhizae: some microorganisms, such as FUNGI, are present in soil, which can develop symbiotic relationships with plants. This fungi can penetrate plant roots and grow in the cells of the plants. These plants are primary producers, which are eaten by herbivores.
  8. Importance of nitrogen fixing bacteria to farmers.
    It keeps the nitrogen in the soil, so it is not released as nitrogen gas, which is not beneficial to farmers, as plants use nitrogen.
  9. Why do farmers try to impede nitrification?
    Farmers do not want DENITRIFICATION because this makes the oxidized nitrogen present in the fertilizers for growth empty out into the air as nitrogen gas.
  10. What is diazotroph?
    A group of bacteria that is involved with Nitrogen Fixing
  11. Give examples of free-living and symbiotic nitrogen-fixing microorganisms. Are these prokaryotic or eukaryotic?
    • Symbiotic nitrogen-fixing orgs are referred to as rhizobia, and include Rhizobium.
    • Free-Living nitrogen-fixing microorganisms include Clostridium (anaerobic).
  12. Fluorescence in situ hybridization (FISH)
    Uses nucleic acid probes containing specific sequences. Allows to examine the COMPOSITION of microbial populations.
  13. Polymerase chain reaction (PCR)
    Used to detect certain organisms and an assessment of population characteristics
  14. Denaturing gradient gel electrophoresis (DGGE)
    Used to SEPARATE and EXAMINE a set of amplified sequences within a genome
  15. Genomics
    Useful for study of ecology, as genomic info from one organism may be applied to others
  16. Distinguish between oligotrophic and eutrophic waters.
    • Oligotrophic � growth of photosynthetic organisms is LIMITED due to LACK of certain nutrients
    • Eutrophic � growth of these organisms is plentiful due to rich content of nutrients
  17. Describe the effects of nutrient-rich runoff on water.
    This can result in the growth of many different orgs such as ALGAE and CYANObacteria. These organisms take in oxygen and make water hypoxic (lacking Oxygen), now termed a dead zone in the water.
  18. Eutrophication
    Involves addition of natural or artificial substances to the aquatic system. This example is cyanobacteria or algae, which consume oxygen and cause ultimate death to fish and other aquatic life.
  19. Explain how nutrient rich runoff can cause waters to become hypoxic.
    The algae and cyanobacteria (oxygenic phototroph) utilize oxygen and through this, they depleat the oxygen content in the waters, leading them to become hypoxic.
  20. Types of microorganisms mostly found in soil.
    Bacteria, fungi, algae, protozoa, endospores
  21. Define soil as a microbial habitat.
    Contains organic material, oxygen and water. Has much microbial life including bacteria, protozoa, worms, plant roots
  22. Define biogeochemical cycles and list three specific examples.
    • This is the cyclical path that ELEMENTS take as they flow through NON-LIVING and LIVING components of ecosystems.
    • 1.Carbon Cycle
    • 2. Nitrogen Cycle
    • 3. Sulfur Cycle
  23. List three uses of chemical elements in biogeochemical cycles.
    • 1.BIOMASS production � element incorporated into cell material
    • 2.ENERGY source � from the reduced form of the element
    • 3.TERMINAL E- ACCEPTOR � the electrons from energy source are transferred to OXIDIZED form of element during respiration
  24. Ecological niche
    describing the relational position of a species or population in its ecosystem to each other
  25. Biofilm
    An aggregate of multiple microorganisms which cells adhere to each other and the surface.
  26. Microbial ecology
    Study of relationship of Organisms to each other AND the environment
  27. Community
    Microbes in a biofilm that may exhibit different relationships (symbiotic or competitive)
  28. Ecosystem
    Contains certain organisms and characteristic PHYSICAL conditions. Ie, lakes, rivers, forest
  29. Biosphere
    Region of the earth inhabited by certain organisms
  30. Biodiversity
    # of species present and evenness of diversity
  31. primary producers
    These are AUTOtrophs, converting CO2 into ORGANIC materials. Ie, plants, cyanobacteria (phototrophs). Ie, oxidizing inorganic compounds for energy (chemoautotrophs)
  32. consumers
    • These are HETEROtrophs, rely on primary producers
    • Primary consumer: Herbivore that eats primary producers (autotrophs)
    • 2nd Consumer: Carnivore that eats Herbivores
    • 3rd Consumer: Carnivore eating another carnivore
  33. decomposers.
    Heterotrophs that digest remaining primary producers and consumers. Specialize in digesting complex materials
  34. Autotrophs
    Primary producers: use the sunlight to convert CO2 into organic products
  35. Heterotrophs
    Consumers: use primary producers as carbon source and obtain energy from this
  36. What kind of bacteria do you expect to find on the top layer? How do they help in growth of other kinds of bacteria beneath the surface?
    At the top are the aerobic bacteria. These give rise to the growth of more anaerobic bacteria beneath the surface, as the top layer is using and is exposed to all of the available oxygen.
  37. Which factors determine the type of microbial community of a biomass?
    • 1.The amount of nutrients available in the environment.
    • 2.The amount of microbial competition, which generally gives rise to growth.
    • 3.Antagonism helps to determine makeup of population.
    • 4.Any environmental change will have an effect on the bacterial community.
  38. How do environmental changes affect the composition of microbial communities?
    The new environment presents different set of conditions, forcing bacteria to adapt to the new conditions. This can result in bacterial death or mutants of certain bacteria being able to survive better and thrive in that new environment.
  39. Describe how microorganisms grow in low-nutrient environments.
    • Can extract amounts of nutrients from H20
    • These organisms usually have highly efficient transport systems for nutrient procurement
    • Usually involve bacteria in biofilms
  40. Distinguish between microbial competition and antagonism.
    • Competition involves two organisms competing for nutrients and this results in much growth of both organisms and high nutrient usage.
    • Antagonism involves bacteria that may use certain nutrients so another bacteria cannot survive, or bacteria that is produced to kill certain strains of other bacteria.
  41. Describe how environmental changes have an effect on microbial communities.
    • They can alter bacteria�s role in community, ie, some bac will stop producing enzymes if it is no longer beneficial.
    • Mutations that were a minority of the bac population may now become better suited for the new environment.
Card Set
ch 30 flashcards.txt