Which statement best describes why warm ocean currents are usually surface currents?
a)warm water is less dense than cold water.
b)ocean tides bring warm water to the surface.
c)warm water contains more salt than cold water.
d)ocean water loses heat to the air at the surface.

How is ribosomal rna useful as a molecular clock? a. a large portion of the dna ring is not vital to structure or function, allowing it to accumulate neutral mutations. b. its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. c. a slow mutation rate makes it useful for determining evolutionary relationships between ancient species. d. it is only found in select organisms, making it easier to compare relationships between species that have it.

Along what geographical feature are most of the oil producing regions located

2points what do bacteria have in common with the cells of other living organisms?