Question

) Imagine that you are studying a newly discovered bacteria from a hot spring in Yellowstone National Park. You examine the nitrogenous bases of this organism, and find that 10% of the nitrogenous bases in its DNA are adenine. What percentage of nucleotides are cytosine

Answer 1

Cytosine- 40%

Step-by-step explanation:

DNA is the genetic material in virtually all living organisms. It is a molecule made up of long chains of nucleotides, which are its building block. Four types of nucleotides make up the DNA molecule viz: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C).

According to Erwin Chargaff in his rule regarding DNA composition, he stated that in a DNA molecule, the amount of adenine must equal thymine while that of guanine must equal cytosine. In a nutshell, the total of all the base pair must equally be 100% i.e. (A + T) + (G + C) = 100%.

In this case where a newly discovered bacteria from a hot spring in Yellowstone National Park was found to contain 10% of adenine in its DNA. Since Adenine is 10%, Thymine base must also be 10% in accordance to Chargaff's rule.

Hence, 10% + 10% + (G + C) = 100%.

20% + G + C = 100%

G + C = 100 - 20

G + C = 80%

Since, G and C must be equal, then G = C = 80% ÷ 2 = 40%. This means that the percentage of cytosine will be 40%.