Looking at the geologic timeline, what is the pattern that scientists use to determine when an ERA begins and ends? Group of answer choices Scientists have divided the eras into large, equal intervals of time. An era begins every time a new species emerges in the fossil record. Scientist use the emergence and extinction of species.

answer: the answer is b

"do a testcross with a homozygous recessive plant."

thinking it would be physical characteristics

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.