The ratio of adenine to guanine is nearly 1:1. Hence the correct option is c.
The analysis of nucleotide ratios across different organisms, as presented in the table, reveals intriguing patterns in the composition of DNA. Notably, the observation that the ratio of adenine to guanine is consistently close to 1:1 across various species is a significant finding. This implies a balanced occurrence of adenine and guanine bases in the DNA of different organisms, suggesting a degree of universality in the molecular structure of DNA.
On the other hand, the ratios of cytosine to guanine and cytosine to thymine vary, indicating species-specific variations in the composition of these base pairs. The consistency in the adenine-to-guanine ratio, approaching 1:1, underscores the foundational principle uncovered by Chargaff – that while the same four bases exist in all DNA, their proportions exhibit variability among different organisms. Hence the correct option is c.