D. why are both the gene of interest and the plasmid cut with the same restriction enzyme? e. what is the role of dna ligase in this process? 11. why is the dna sample to be separated by gel electrophoresis always loaded at the cathode or negative end of the power source? 12. explain why shorter dna molecules travel farther down the gel than larger molecules. 13. the polymerase chain reaction (pcr) is a nobel prize–winning idea that is used by scientists to amplify dna, particularly when the quantity of dna is very small or contaminated. explain the three initial steps that occur in cycle 1 of pcr.

What best explains whether bromine (br) or neon (ne) is more likely to form a covalent bond? bromine forms covalent bonds because it has seven valence electrons, but neon has eight valence electrons and already fulfills the octet rule. bromine forms covalent bonds because it has many electron shells, but neon has only two electron shells and is tightly bound to its electrons. neon forms covalent bonds because it can share its valence electrons, but bromine has seven valence electrons and can gain only one more electron. neon forms covalent bonds because it has only two electron shells, but bromine has many electron shells and will lose electrons in order to fulfill the octet rule.