Which element is represented by the letter X? 1.
silicon
2.
lead
3.
nitrogen
4.
hydrogen

Why are some people more concerned about shark survival than about shark attacks?

The table below shows the elements that mainly comprise each of the four layers of earth: elements in layers layer main elements crust oxygen, silicon mantle iron, magnesium outer core iron, nickel inner core iron which of these elements make up the layer that is 0.2 to 1.1 percent of earth's total diameter?

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?