Topography and Zones
About what percentage of the earth’s surface is covered by oceans?
71%
Because clams, corals, and anemones are attached to or live on the bottom, we call them __________ organisms.
benthic
The oceans of the world are divided into four completely separate basins.
False; 5 separate basins, not 4
An oceanographer is a(n) _______________
scientist.
marine
This area of the open ocean has a relatively constant salinity and good water clarity.
photic
Which ocean basin covers the largest percentage of the earth’s surface?
A. Pacific
B. Atlantic
A. Pacific
Which element is the main chemical building block of all living things?
Carbon
Mean sea level is slowly rising in most locations around the world.
True - warmer temperatures are causing glaciers to melt adding water to the world ocean
Sea level that varies with the tide and differs from place to place is called the __________ sea level
Local
This area of ocean above the continental shelf is similar to the photic zone.
littoral
Island arcs are most often associated with __________.
A. oceanic trenches
B. fracture zones
C. continental shelves
D. mid-ocean ridges
A. Ocean Trenches
Of those listed below, the most important source of fixed nitrogen for marine
organisms is
A. the decomposing tissues of dead animals and plants.
B. artificial fertilizer runoff.
C. cyanobacteria.
D. atmospheric nitrogen.
C. Cyanobacteria
The intertidal zone is the life zone just below the lowest low tide near shore.
False
The shallow, submerged edge of a continent is called a(n) ______________ ____________.
continental shelf
No light from the surface reaches these two zones.
aphotic or abyssal
In which life zone must organisms cope with the greatest variability of conditions?
Intertidal Zone
____________ organisms in this area are more likely to be exposed to light from the surface.
Benthic
The near-shore littoral and open ocean photic zones include the same depth band of the oceans.
True
Underwater ridges of rocklike structures formed by organisms that support a large variety of life are called ______________ ___________.
coral reefs
Pelagic animals, many bioluminescent, are the only living things here.
aphotic
Organisms that live between the low tide mark at the shore and the edge of the continental shelf live in the __________ zone.
littoral
Marine organisms in this zone must be very mobile or have a sturdy design and a good grip on surfaces.
Intertidal
Minimizing the runoff of artificial fertilizers into the ocean is an important part of exercising biblical dominion of the ocean environment.
True
Organisms that are not attached to or do not live on the ocean floor are considered ____________ organisms.
pelagic
The only nutrients here come from marine snow.
abyssal zone