1. In the "side supports" of the
DNA ladder,
[Select]
(what kind of bond?) connect the
sugars and phosphates.
2. In the "rungs" of the DNA ladder,
[Select]
(what kind of bond?) holds the
nitrogenous bases of one strand
to the nitrogenous bases of the
other strand.
3. The heat added during PCR
affects the bond between the
nitrogenous bases in the "rungs"
of the DNA ladder by
[Select]
(doing what to those bonds?).
4. A cell
[Select]
(does or does not?) also use heat
to accomplish the same thing
when the cell replicates its DNA.
