A segment of double-stranded DNA contains 31% Adenine (A) bases.
a. What are the percentages of the other three bases in the DNA segment? (Count bases on
both strands.)
C: T: G:
To find the percentages of the other three bases (Cytosine, Thymine, and Guanine) in the DNA segment, we need to consider the base pairing rules in DNA. In a double-stranded DNA molecule, Adenine (A) always pairs with Thymine (T) through two hydrogen bonds, and Cytosine (C) always pairs with Guanine (G) through three hydrogen bonds.
Since the segment of DNA contains 31% Adenine (A), the other strand of DNA will have 31% Thymine (T) because of base pairing. Therefore, the percentage of Thymine (T) is also 31%.
Now, we can find the percentages of Cytosine (C) and Guanine (G) by subtracting the percentages of Adenine (A) and Thymine (T) from 100% since DNA is composed of these four bases.
C = 100% - (percentage of A + percentage of T)
= 100% - (31% + 31%)
= 100% - 62%
= 38%
Therefore, the percentage of Cytosine (C) is 38%.
G = 100% - (percentage of A + percentage of T)
= 100% - (31% + 31%)
= 100% - 62%
= 38%
Therefore, the percentage of Guanine (G) is 38%.
To summarize:
The percentages of the other three bases in the DNA segment are:
Cytosine (C): 38%
Thymine (T): 31%
Guanine (G): 38%