What conclusion would be most appropriate about the genetic variation between humans and the three apes as illustrated by the phylogenetic tree?
a) genetic variation between all four organisms is non-existent.
b) the genetic variation between all four organisms is about the same.
c) the genetic variation between humans and orangutans is the greatest.
d) humans branched off from the other three animals due to great genetic variations.

Assume that you are interested in separating short (200-400 bp) dna molecules from a pool of longer molecules in the 10,000-20,000 nucleotide range. you have two recipes for making your polyacrylamide gels: one recipe uses 1.5 percent agarose and would be considered a “hard gel,” while the other uses 0.5 percent agarose and would be considered a loose gel. which gel should you use to separate the short (200-400 bp) dna molecules from a pool of longer molecules in the 10,000-20,000 nucleotide range?