Answer to Question 1ANS: C
Desiccation is the drying out of an organism. Motile animals can move towards water, but sessile
organisms must await the return of water. They trap water within their shells to keep their gills moist.
Some have a protective mucous which prevents water loss. Information can be found in the section
Examples of Marine Communities.
Answer to Question 2ANS: C
The Arctic does not have a deep scattering layer. Perhaps this is due to the abundance of nutrients in
the deep water and the waters above. Information can be found in the section Examples of Marine
Communities.
A classification system for living and extinct organisms.
Soil profile exposed in a boreal forest site, showing LFH, A, B, and C horizons.
Mutualisms, such as those that occur among plants and pollinators, generally involve large numbers o
Erythroblastosis fetalis. (a) The condition occurs with an RH+ father and RH– mother. (b) First preg
T wave (ventricular repolarization).
Spontaneous Mutation Rates at Various Loci in Different Organisms