Ideally, the answer is 100% GC content, but this percentage is not observed in any living organism.
GC content in living organisms can be less than 30% or more than 80%.
The DNA having greater than 80% GC content is considered to be stable.
Explanation:
The stability of a double -stranded DNA molecule depends on the number of hydrogen bonds present in between the double helix.
Hydrogen bonds are formed between the purine (A,G) and pyrimidine (T,C) nitrogenous bases.
Adenine (A) and Thymine (T) - two hydrogen bonds.
Guanine (G) and Cytosine (C) - three hydrogen bonds.
So the DNA double helix having more GC content will have more hydrogen bonds and hence would be more stable.
The GC content in a DNA molecule is determined by the ratio of the number of GC bonds present in the DNA to the total number of bonds (AT and GC) present.
