cytosine makes up 42% of the nucleotides in a sample of dna from an organism. approximately what percentage of the nucleotides in this sample will be thymine?
To determine the approximate percentage of thymine in the sample of DNA, we can use the base pairing rule in DNA: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).
Since cytosine makes up 42% of the nucleotides in the DNA sample, we can assume that guanine also makes up 42% because they pair together. Therefore, the total percentage of cytosine and guanine combined is 42% + 42% = 84%.
Since the DNA double helix structure requires complementary base pairing, the percentage of adenine (A) and thymine (T) must also be equal. Therefore, the percentage of thymine can be estimated as half of the remaining DNA nucleotides.
To calculate the approximate percentage of thymine, we subtract the combined percentage of cytosine and guanine (84%) from 100% and then divide by 2:
(100% - 84%) / 2 = 16% / 2 = 8%
So, approximately 8% of the nucleotides in this sample of DNA will be thymine.