The amino acids sequences for hemoglobin in humans and gibbons differ by one amino acid. this molecular similarity in these two species indicates that a) are the same species b) were recently in the same species c) are not closely related d) share a common ancestor

D because the closer they are geneticaly, the more related they are. A cactus and a squirl have little to no similer genetic makeup so A human and a gibbon that already have a conspericy around them as to evolution would have closer makup.

≅200-130 milions years ago pangea splited in 2 continents

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.