What does a cell have that determines if it is prokaryotic or eukaryotic?

1)dna

2)organelles

3)proteins

4)a cell membrane

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

What could happen if two base pairs on a strand of dna or switched

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?