Question

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?

Answer 1

Answer:

75

Explanation:

got the answer right

Answer 2

Answer:

If a DNA double helix is 100 nucleotide pairs long and contains 75 adenine bases then it contains 25 guanine bases.

Explanation:

Adenine has only two hydrogen bonds with thymine, but guanine has three hydrogen bonds with cytosine. Bonding pairs can also form in the opposite direction.

Because there are 100 nucleotides pair  in this strand and 25 adenine bases, there must be 25 thymine bases as well.

As a result, there are a total of 25 + 25 = 50 adenine and thymine bases. There are now 200 - 50 = 150 bases left. Because cytosine and guanine are bonded together, their levels are equal. The number of guanine or cytosine bases can now be calculated by dividing by two.

150 ÷ 2=75

So 75 is guanine bases.