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p393 1-15
1. DOMAINS & Kingdoms:
ARCHEA—simple microscopic bacteria-like organisms - halophiles (“salt-loving”), thermophiles
(“extreme-heat loving”), methanogens (“methane-producing”)
BACTERIA—simple life forms whose cells have no membrane-bound organelles; no nucleus, etc (E.
coli, streptococcus, cyanobacteria, etc)
EUKARYA—complex organisms whose cells have a membrane-bound nucleus and other membranebound organelles.
Animalia— multicellular, heterotrophic, no cell walls, generally motile (can move toward prey and away
from predators)
Plantae— multicellular, autotrophic, photosynthetic, chlorophyll in clhoroplasts, cell walls with
cellulose, generally sessile (stuck in one spot for life!)
Fungi— heterotrophic; cell walls with chitin (mushrooms, molds and lichens)
Protista—unicellular AND multicellular;
plant-like (algae)
animal-like (paramecium, amoeba, euglena) and
fungus-like (slime molds)
2.
- Plankton can adjust their buoyancy so they can float at different levels in the ocean, but they cannot propel
themselves efficiently through water. (Plankton includes protists (including algae), plants, animals, and bacteria.
They make up most of the biomass because they are so plentiful and they inhabit such a large area of the oceans.)
drifters/floaters
- Nektonic organisms are active swimmers
- Benthonic (benthic?) organisms live at or just above or just below the seafloor. (bottom dwellers)
3. Plankton:
phytoplankton—microscopic, unicellular, photosynthetic algae
zooplankton— microscopic, unicellular animals or animal-like creatures
bacterioplankton—floating bacteria
macroplankton—large animals and algae (jellyfish, Sargassum/kelp/seaweed)
picoplankton—very small bacterioplankton (0.2 to 2 micrometers μm. Human hair ranges from ≈20μm -150μm)
holoplankton—spend their entire lives as plankton
meroplankton—spend larval/juvenile stages as plankton
Benthos:
epifauna—live on the surface of the seafloor
infauna—live buried in sediment or shells
nektobenthos—live on bottom, crawl or swim through water
4. Relative number of species of animals?
- terrestrial environment has highest number of species (86%)
- benthic environment has many more than pelagic, but less than terrestrial (13.7% of all species on earth)
- very few in pelagic environment (0.3% of all species on earth)
The number of species increases with the diversity of ecosystems:
- The pelagic ocean is rather constant in temperature and salinity.
- The benthic ocean is also constant in temperature and salinity but variable in the quality of the
seafloor (rocky, sandy, gentle slopes, steep slopes, etc.)
- The terrestrial environment is the most varied in ecosystems, so it has the greatest number of
species that have adapted to these small but very different environment niches.
5. Differences between marine algae and land plants?
- Marine algae live in water and won’t dry out unless the water evaporates.
Why are land plants more complex?
- They have to find a way to transport water from air or soil throughout their tissues. They are
surrounded by air and must expend energy to keep water from evaporating out of their tissues.
6.
SA = Avg linear dimension squared x 6
V = avg linear dimension cubed
a) 1 cm
SA = 1x1x6 = 6 cm2
V = 1x1x1 = 1 cm3
SA/V = 6/1 = 6:1
b) 3 cm
SA = 3x3x6 = 54 cm2
V = 3x3x3 = 27 cm3
SA/V = 54/27 = 2:1
c) 5 cm
SA = 5x5x6 = 150cm2
V = 5x5x5 = 125cm3
SA/V = 150/125 = 6:5
(1.2 : 1)
The 1cm organism has a much higher SA to V ratio (Smaller organisms have higher surface area-to-volume ratios and
don’t sink as easily.)
7. Other adaptations that help keep organisms from sinking include:
- more appendages to increase their SA to V ratio.
- feathery appendages that also increase SA to V ratio
- some have oil within them that reduces their density and increases their buoyancy (sperm whale’s big brick
head is full of oil)
8. Discuss how decreased water temperature affects the water’s density, viscosity, and solvency.
As water temperature decreases:
- density increases
- viscosity increases
- the ability of water to hold gas in solution increases (making it easier for oxygen consuming
organisms to breathe)
As density and viscosity of seawater increase:
- floating organisms have more buoyancy
- active swimmers have more difficulty moving through water.
- more oxygen can be held in solution in seawater,
9. What are differences in cold- and warm-water marine species?
- Cold-water plankton:
does not have as many appendages (to help them float) as warm-water plankton.
- Warm-water plankton:
- is smaller in size than cold water plankton.
Warm water species in general:
- grow faster
- reproduce more frequently
- have shorter life spans.
- are more numerous than cold-water species.
10. Eury- means “broad” or “wide.” Steno- means “narrow.”
- eurythermal and euryhaline mean the ability to withstand a wide range of temperatures and salinities
respectively. These organisms tend to live in shallow coastal waters (example, estuaries) where wide ranges of salinity
and temperature are the norm. (Bull shark is the classic euryhaline organism)
- stenothermal and stenohaline mean the ability to live within a narrow range of temperatures and salinities.
These organisms tend to live in deep water where narrow ranges of salinity and temperature are the norm.
11.
In osmosis, water molecules move through semipermeable membranes from regions of low concentration of
dissolved elements (high conc. of H2O) to regions of high concentration if dissolved elements (LOW conc. of H2O).
In diffusion, molecules or ions of soluble substances move through water from regions of high concentrations to
regions of lower concentrations.
During osmosis three transfers can occur simultaneously across the membrane:
- water moves into and out of the cell as needed to maintain homeostasis
- nutrients diffuse into the cell as concentrations dictate
- wastes diffuse out of the cell as concentrations dictate
12. Hypotonic fish in the ocean (i.e. salt water fish) have body fluids with a lower salinity compared to the salinity of the
ocean. Because their cells have a lower concentration of SALTS than the ocean, they have a HIGHER concentration
of WATER than the ocean, so water flows out of their cells by osmosis. To replace this lost water, they drink ocean
water and remove the salt. These fish excrete highly concentrated urine.
13.
- As implied in question #8, Gases can come out of solution in seawater more readily if water temperature is
higher. Thus, cooler water can hold more gas than warmer water can.
- Many marine organisms have gills that allow dissolved O2 to diffuse directly from seawater into their
bloodstreams (the same way your lungs allow O2 to diffuse directly from the air into your bloodstream).
- As you learned drawing diagram 13-15 on p 385, fish take in seawater through their mouths, pass the water over
the gills that extract the oxygen, and expel the water from gill slits.
14. How does the DSL (deep scattering layer) vary daily?
The DSL is made up of dense concentrations of marine organisms that feed in the euphotic zone at night,
but descend to greater depths during the day to avoid predation. Organisms in the DSL include copepods, krill, and
lantern fish.
15. Subdivisions of the pelagic and benthic environments (see chart on p 388 for details BUT:
MAIN THINGS TO KNOW HERE:
Neritic – ocean near coast, above continental shelf
Pelagic – open ocean, out beyond continental shelf
Benthic – ocean bottom
Euphotic – “good light” (surface to 100m down plenty of sunlight for photosynthesis)
disphotic – “not so good light” (100m down to 1000m down. SOME light but not much)
aphotic – “without light” (below 100m; essentially pitch black.)