When people get their hair chemically straightened, one chemical is put on the hair to break the disulfide bond that give the hair strands their shape and a second chemical is used to reform the disulfide bonds to hold the hair in a new position. what level of protein is affected by these processes. why doesnt the hair stay straight forever after treatment

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?