Answer:
The author means to say that Genetic difference exist between different species.
Step-by-step explanation:
Comparison between protein and nucleic acid
Similarity
1 Both nucleic acid and Proteins are Macromolecules
2 Both nucleic acid and protein are the main component of central dogma of molecular biology
Difference
1 nucleic acids are the polymer of nucleotides whereas proteins are the polymer of amino acids.
2 nucleic contain nitrogen bases whereas protein contain open reading frame composed of codons.