Which played a major role in altering wind patters and ocean currents?
volcanic eruptions
ice ages
movement of continents
solar flares

Temperatures in ponds and lakes vary by season. select the best answer from the choices provided t f

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas

For which of the following ions is the intracellular concentration typically higher than the extracellular concentration? a. sodium b. calcium c. magnesium d. potassium e. chloride