11. What is the numeric
relation between pyrimidine
and purine bases in the DNA
molecule? Is that relation
valid in RNA molecules?

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The DNA molecule is made of two bound
polynucleotide that form a helical
structure (the helix). The binding
of the two chains is between their
nitrogen-containing and it always
obeys the following rules: adenine (A),
a purine base, binds with thymine (T), a
pyrimidine base, and guanine (G), a
base, binds to cytosine (C), a
pyrimidine base. Therefore in one
molecule of DNA there will be the
number of adenine (A) and thymine (T)
and same number of cytosine (C) and
guanine (G). The quantities of purine
and of bases then will also
be the same in a % proportion for
each type. The relation A = T and C =
G, or A/T = C/G = 1, is called Chargaff’s
relation and the pairing rules described
above are known as rules.

In RNA there are not nucleotide
chains. RNA is a simple chain molecule
and there is no necessary
proportionality of -containing
bases to form it.