You have isolated the DNA of an organism and have done some tests in the lab. One of the tests showed that 18% of the bases were Thymine. Based on this knowledge alone, what is the percentage of Guanine that you expect?
In DNA, the base pairs are always complementary, meaning that Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C).
Since the DNA molecule is double-stranded, the percentage of Thymine (T) base pairs should be equal to the percentage of Adenine (A) base pairs. Therefore, if 18% of the bases are Thymine (T), then 18% of the bases will also be Adenine (A).
Since the total percentage of bases should add up to 100%, and we already have accounted for 18% for Thymine and Adenine, we can calculate the percentage of Guanine (G) as follows:
Total percentage of bases - [Percentage of Thymine (T) + Percentage of Adenine (A)] = Percentage of Guanine (G)
100% - (18% + 18%) = 100% - 36% = 64%
Therefore, based on this knowledge alone, you would expect the percentage of Guanine (G) to be 64%.