Mid-ocean ridges, which contribute to the process of sea-floor spreading, form as a result of .

A. earthquake activity that causes subduction

B. a rift valley, like the Red Sea, being filled

C. older ocean floor that moves toward the ridge

D. volcanic activity that produces magma

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

this protocol provides a detailed procedure for total protein extraction for western blot analysis from achieved samples following trizol isolation of rna.

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.