Review sheet – Chapter 5 Understand that microorganisms are the most important primary producers in the marine environment Know that viruses are made of nucleic acid, either RNA or DNA Know that viruses are a critical component of the marine food web because they parasitize bacteria and plankton releasing organic matter into the marine environment for consumption by microorganisms Understand that viruses also release nutrients which can be used by photosynthetic organisms Know that viruses are believed to be responsible for half of the bacterial mortality in aquatic ecosystems Know that the amount of viruses in any given marine environment is dependent on the abundance of the host organisms which they invade Know that for every liter of seawater, there are (on average) 100 billion (100,000,000,000) viruses Understand that all prokaryotes are unicellular Understand that prokaryotes lack a nucleus and other membrane-bound organelles Know that organisms in domains Archaea and Bacteria are all prokaryotes (prokaryotic) Understand that most organic matter in the marine environment is consumed (decomposed) by bacteria Know that marine snow consists of detritus and the bacteria that is feeding on it Know that detritus refers to non-living particulate organic matter Understand that aggregates of material will sink much faster than individual cells Understand that dissolved organic matter makes up most (90%) of the organic matter in the ocean Know that cyanobacteria are photosynthetic bacteria which contain chlorophyll as well as phycocyanin as their photosynthetic pigments Know that cyanobacteria are also known as “blue-green algae” and were among the first photosynthetic organisms on Earth Know that Archaea (Domain Archaea) are prokaryotes Know that Archaea include the “extremophiles” – microorganisms capable of living in extreme or harsh environments Know that some Archaea can survive (and thrive) at temperatures as high as 250°F (121°C), the highest known of any organism Understand that Archaea provide evidence for life on Earth Understand that prokaryotic autotrophs derive energy from photosynthesis or chemosynthesis, but that eukaryotic autotrophs can only derive energy from photosynthesis (no chemosynthesis) Know that chemosynthesis is the process by which prokaryotic autotrophs derive energy not from light by from chemical compounds Know that hydrogen sulfide is an example of a chemical compound that chemosynthetic organisms derive energy from (to convert carbon dioxide into organic matter) Understand that the base of the food web at and near hydrothermal vents is based on chemosynthetic prokaryotes that are using hydrogen sulfide as their energy source Know that anaerobic bacteria do NOT use oxygen to respire, and are found in anoxic (no oxygen) environments Know that all protists (Kingdom Protista) are eukaryotes (belong to the domain Eukarya) Know that algae are photosynthetic protists which lack true roots, leaves and stems and other specialized tissues, flowers, etc. (they are distinct from plants) Understand that algae include unicellular organisms (e.g. ,diatoms, dinoflagellates, etc) and multicellular organisms (e.g., seaweeds) Know that diatoms have cell walls made of silica, and consist of 2 tightly-fitted halves Know that diatoms are unicellular protists (unicellular algae) Know that diatoms can sink dead to the seafloor forming diatomaceous oozes Know that dinoflagellates have 2 flagella – one that wraps around a groove in its center and one that hangs freely Know that dinoflagellates are unicellular protists (unicellular algae) Know that dinoflagellates are important in tropical (warm) regions, while diatoms are important in temperate and polar regions Know that dinoflagellates are responsible for many of the “red tides” that occur in marine environments Know that zooxanthellae are symbiotic dinoflagellates that live in close association with coral, giant clams, sea anenomes and sponges Understand that zooxanthellae photosynthesize within the tissues of their host organism receiving nutrients and shelter from the host, and providing organic matter in return Know that coral bleaching occurs when a coral loses its symbiotic zooxanthellae Know that coccolithophorids are unicellular protists (unicellular algae) Know that coccolithophorids have plates made of calcium carbonate Know that foraminiferans are unicellular protists (unicellular algae) Know that foraminiferans have a shell made of calcium carbonate Know that dead foraminiferans can form foraminiferous oozes Know that radiolarians are unicellular protists (unicellular algae) Know that radiolarians have shells made of silica, and that dead radiolarians can form radiolarian oozes Know that ciliates are unicellular protists (unicellular algae) Know that ciliates possess numerous cilia which is used for locomotion and feeding Know that tintinnids are ciliates that build vase-like structures Know that fungi (Kingdom Fungi) are eukaryotic (domain Eukarya) Know that all fungi are heterotrophic and absorb (not ingest) nutrients from their environment Know that marine fungi include decomposers and parasitic (disease-causing) organisms