What is the main source of phosphorus?

Exactly what kind of weather conditions would a cold front produce?

Which statement explains what upwelling causes? a. upwelling causes tides to rise and fall. b. upwelling causes changes in the direction of currents. c. upwelling causes nutrients, minerals, and tiny organisms to rise. d. upwelling causes currents in the pacific ocean to change direction. i think the answer is c.

In the following diagram, four different index fossils are labeled: which of the labeled fossils comes from the oldest organism? a b c d