Two subgroups of a population separated by a river are rejoined when a drought causes the river to run dry. assuming that speciation has not yet occurred, what is true about the two subgroups?

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

the endomembrane system i think

one part of the electromagnetic spectrum that arrives on earth as solar radiation from the sun is the visible spectrum. wavelengths of the visible spectrum combine to form what we refer to as

answer - d) ultraviolet radiation.

violet /   380–450 nm / 668–789 thz

violet is number 1 in the chart of visible light.