BIOL113 M2 L5

• Cyanobacteria 

  These are critical environmental bacteria that produce oxygen
• One of the most abundant phototrophs in oceans are Prochlorococcus, an example of marine Cyanobacteria. Previous to Carl Woese, what were Cyanobacteria called? 

  Blue green algae 
• The great plate count anomaly is the observation that we are able to culture only about 1% of the bacteria and archaea that we can see underneath the microscope. 
• Define the wrong temperature hypothesis :

  When we plate prokaryotes out in the laboratory we are not able to grow them because we attempt to incubate them at the wrong temperature
• Define the cross feeding hypothesis :

  When we plate prokaryotes out in the laboratory they do not grow because they are missing partners that they would normally be exchanging metabolites with
• Define the wrong nutrients/ environment hypothesis

  When we plate prokaryotes out in the laboratory they do not grow because the media that we use has inappropriate nutrients or the environment (atmosphere) is unsuitable for the prokaryotes.
• Acanthamoebae castellani is a well-studied amoeba that is common in terrestrial environments. Describe 3 things about this amoeba.

  This organism is completely sequenced. ,

  This organism can cause encephalitis in immunocompromised patients. ,

  This organism consumes bacterial prey by phagocytosis. 
• Describe 3 things about Dictyostelium discoideum 

  This organism is completely sequenced. ,

  This organism consumes bacterial prey by phagocytosis. ,

  This organism undergoes a multicellular development stage once food is scarce. Individual cells cooperate to become a motile slug and a fruiting body. 
• Eukaryotic cells have very few traits that are universally conserved. The traits that are considered to be common for all Eukaryotes include...

  A cell or cells that have a nucleus with a nuclear envelope that includes nuclear pores. 
• Describe Phytophthora agathidicida 

  This is a oomycete protozoa, which is a fungi-like eukaryote. They are filamentous and heterotrophic.

  They have mobile zoospores and are a disease of Kauri trees in New Zealand. 

  It has recently been discovered to be susceptible to kanuka, which inhibits the germination of zoospores. 
• Protists are defined as eukaryotes that are not land plants, animals or fungi. It is also common to hear it said that protists are "embedded in the tree of life'. Describe what this means:

  Protists are highly diverse microorganisms who are not a single group, rather protists can be more closely related to fungi, animals and plants than they are to one another
• What are extremophiles ?

  Extremophiles are organisms that thrive in extreme environments that are inhospitable to most other forms of life
• give examples of archaea that are extremophiles

  methanogens, sulfolobales, and halophiles
• Why are methanogens considered extremophiles ?

  They thrive in anaerobic conditions such as swamps, marshes, landfills marine benthic sediments and the digestive tracts of animals. Methanogens are unique among extremophiles because they produce methane as a byproduct of their metabolism, making them important contributors to the global carbon cycle. They were the first of the archaea recognised by carl woese.
• why are sulfolobales considered extremophiles ?

  They thrive in extremely acidic and high-temperature environments, typically found in volcanic areas such as hot springs and geothermal vents. These organisms can withstand pH levels as low as 0 and temperatures up to 90°C (194°F). Some respire by oxidising sulfur.
• Why are halophiles considered extremophiles ?

  Thrive in environments with high salt concentrations, such as salt lakes, salt flats, and salt mines, where the salinity levels are often several times higher than that of seawater.
• why is Dictyostelium discoideum a good model organism ?

  It is completely sequenced

  it consumes prey by phaogcytosis making it an ideal model for studying cellular processes like nutrient uptake and digestion

  its multicellular development stage (motile slug and fruiting body) offers insights into cellular cooperation and multicellular development

  It is also well-suited for studying various cellular processes such as the cytoskeleton, chemotactic motility, and cellular aging.

  its interactions with fungal or bacterial pathogens make it valuable for studying infectious diseases