The percentage of the adenine (A) nucleotide in a particular organism's genome is 30%. The percentages of the other nucleotides must be approximatelyA. 70%T, 0%G, 0%CB. 30%T, 20%G, 20%CC. 20%T, 30%G, 20%C

Question

Biology

Ashlyn Fisher

29 August, 03:51

The percentage of the adenine (A) nucleotide in a particular organism's genome is 30%. The percentages of the other nucleotides must be approximatelyA. 70%T, 0%G, 0%CB. 30%T, 20%G, 20%CC. 20%T, 30%G, 20%C

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Answers (1)

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Phoebe Pearson · Answer 1

B. 30%T, 20%G, 20%C

Explanation:

The Chargaff rule states the relationship in DNA molecules based on nucleotide composition. It is based on the fact that in a double-helical DNA molecule, a purine base of a strand always pairs with a pyrimidine base of the other strand. According to the Chargaff rule, the number of adenine bases equals the number of thymine bases, and the number of guanines equals the number of cytosines.

According to the given information, the percentage of adenine (A) in the DNA of a particular organism is 30%. This means that the DNA of this organism would have 30% of thymine nucleotides. Out of total 100% DNA nucleotides, the proportion of guanine + cytosine nucleotides = 100 - (30 + 30) = 100-60 = 40.

In a double-helical DNA, the number of guanines equals the number of cytosines. Therefore, the percentage of guanine and cytosine nucleotides each = 40/2=20%