An organism whose genetic makeup is 50% C-G bonds would have a(n) _________ melting temperature (Tm), compared with an organism with 20% C-G bonds
a. higher
b. lower
c. equal
d. similar
A
The Tm is the temperature at which the DNA becomes single-stranded, or melts, and is depen-dent on its base sequence (i.e., stretches of double-stranded DNA with more cytosine and gua-nine molecules requiring more heat [energy] to break the three hydrogen bonds between these two bases, in contrast to adenine- and thymidine-base pairing, which has only two hydrogen bonds).
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