Questions for Study and Review
1. A DNA molecule is composed of monomers called
2. Name the three components of a DNA monomer.
a.
b.
c.
3. Name the four nitrogen bases in DNA.
a.
b.
c.
d.
4. Of the bases listed above,
and
are purines, while
and
are pyrimidines.
5. The sides of the DNA "ladder" are made up of alternating units of
and
. These units are held together by
bonds.
6. What unit is found at the 5' end of each DNA strand?
7. The "rungs" of the DNA "ladder" are made up of
These units are held together by weak
bonds.
8.
and
are weakly held together by two hydrogen bonds.
and
are weakly held together by three hydrogen bonds.
9. Do the nitrogen bases attach to the deoxyribose sugar or to the phosphate of the DNA backbone?
10. The DNA molecule is twisted to form a double-stranded
11. The specific arrangement or "sequence" of the paired nitrogen bases is the
of the cell.
12. When and why is it necessary for DNA to replicate?