Oceanography Final Exam Study Guide Covers Chapters 12 13 and 16 Chapter 12 NASA s Definition of Life or Alive Life is a self sustained chemical system capable of undergoing Darwinian evolution Some other ideas about what it means to be alive Consumes energy from the environment Self replicating Functions with liquid water Has a membrane to separate itself from the environment Classification of living organisms Three domains Archaea Prokaryotes no nucleus DNA is not contained Bacteria Prokaryotes no nucleus DNA is not contained Eukarya Eukaryotes has nuclear membrane DNA is contained Five kingdoms Monera bacteria and archaea simplest organisms single celled no nucleus archaea cyanobacteria photosynthetic heterotrophic bacteria Protoctista single and multi celled with nucleus o Algae protozoa Fungi o Mold lichen Plantae multi celled photosynthetic plants o Surf grass eelgrass mangrove marsh grasses Animalia multi celled animals o Simple sponges to complex vertebrates Monera organisms are all Archaea and Bacteria Protoctista Fungi Plantae and Animalia organism are all Eukarya Taxonomic classification Systemized classification of organisms based on physical characteristics and genetic information Acronym to help remember Domain Kingdom Phylum Class Order Family Genus Species Dear King Paul Came Over For Good Soup Species diversity is strongly related to habitat variability There are more species on land than in the oceans due to highly varied habitat characteristics on land The Oceans especially mid depth and deep have relatively uniform conditions Less adaptation required less speciation Marine species are overwhelmingly benthic sea floor dwelling rather than pelagic open sea dwelling since benthic habitats are more varied More than 250 000 identified marine species Most live in sunlit surface seawater Species success depends on ability to o Find food o Avoid predation o Reproduce o Cope with environmental characteristics and physical barriers to movement Plankton drifters floaters non swimmers o Most biomass on Earth consists of plankton o Phytoplankton o Autotrophic make their own food o Zooplankton o Heterotrophic consumers of org matter o Bacterioplankton very small very abundant o Virioplankton viruses in the ocean o Holoplankton o Meroplankton o Spends entire lives as plankton o Spends only part of lives as plankton o Has juvenile or larval stages o Macroplankton o Large floaters such as jellyfish or Sargassum o Nanoplankton Picoplankton o Very small floaters such as bacterioplankton Nekton swimmers Independent swimmers Most adult fish squid and krill Marine mammals Marine reptiles Benthos bottom dwellers Epifauna live on surface of sea floor Nektobenthos swim or crawl through water above seafloor Infauna live buried in sediments o Most abundant in shallower water but found throughout global oceans even in the deepest trenches Main divisions of the marine environment Pelagic division open sea Benthic division sea floor Euphotic zone enough light for photosynthesis Disphotic zone twilight zone not enough light for photosynthesis but still has light Aphotic zone completely dark Adaptations to marine life Narrow range of temperatures in oceans Smaller variations in temperature and environment daily seasonally annually Deep ocean nearly isothermal o Deep Ocean Temperatures only range between 2 and 32 C o Coastal Ocean Temperature ranges between 2 and 40 C o Land Temperatures have a huge range of 88 and 58 C NOTE The specific degree numbers are not important to know but the concept that the Deep Ocean has the least temperature range the Coastal Ocean has a slightly larger temperature range and Land has a huge temperature range is important to know Adaptations of marine organisms 1 Physical support o Smaller size exchange gas easier o How to resist sinking appendages swim bladders etc Many marine fish possess a swim bladder a cavity in the body that can be filled with gas to regulate their position in the water column o Different support structures in cold seawater fewer support structures rather than warm seawater more appendages support structures Warm water is less viscous so the warm water zooplankton have more appendages than the coldwater species 2 Buoyancy o Appendages to increase surface area and slow sinking rate o Natural Oils and fats in micro organisms to increase buoyancy 3 Cold versus warm water species o Smaller in cooler seawater more streamlined Streamlining is important for larger organisms Less resistance to fluid flow along the body Flattened body Tapering back end o Tropical organisms grow faster live shorter reproduce more often o More species in warmer seawater o More biomass in cooler seawater upwelling brings nutrients back to surface waters higher productivity 4 Diffusion o Cell membrane permeable to nutrients for example o Waste passes from cell to ocean o Extracting minerals from seawater o Flows from high concentration to low concentration Dissolved gases need to exchange O2 and CO2 Many animals extract dissolved oxygen from seawater through gills and release CO2 Plankton exchange gases by diffusion through their cell walls 5 Stenothermal o Organisms withstand small variation in temperature o Typically live in open ocean 6 Eurythermal 7 Stenohaline 8 Euryhaline o Organisms withstand large variation in temperature o Typically live in coastal waters o Organisms withstand only small variation in salinity o Typically live in open ocean o Organisms withstand large variation in salinity o Typically live in coastal waters e g estuaries 9 Osmotic pressure o Water diffuses through a semipermeable membrane from less concentrated solutions to more concentrated solutions high pressure to low pressure Hypotonic lower salinity Hypertonic higher salinity 10 Salt regulation Marine versus freshwater fish Isotonic equal salinity o Freshwater fish are Hypertonic salts in body fluids are more concentrated than fresh water so cells tend to absorb water o Marine fish are Hypotonic salts in body fluids are less concentrated than in seawater so cells tend to lose water 11 Water pressure Increases about 1 atmosphere 1 kg cm2 with every 10 m 33 ft deeper o o Many organisms are almost 100 water jellyfish 95 vs human 65 o Many marine organisms do not have inner air pockets o Some have a collapsible rib cage e g sperm whale 12 Coloration o Seawater is very transparent o Many marine organisms see well o Some marine organisms are nearly transparent to avoid predation o Camouflage
View Full Document
Unlocking...