Which factor is used as evidence in supporting the idea that life changes over time? the law of conservation of energy

the existence of vestigial structures that are evidence of something an ancestor of that animal had and the current animal doesn't need

the big bang theory

the time period in which an embryo develops

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?