Final answer:
To split the gDNA sequence into coding and non-coding regions, use a program to extract the appropriate substrings and save them in separate files.
Step-by-step explanation:
To split the gDNA sequence into coding and non-coding regions and save them in separate files, you can write a program that extracts the substring from index 0 to 27 (inclusive) as the coding sequence and saves it in a file called coding_sequence.txt. The remaining characters from index 28 onwards can be extracted as the non-coding sequence and saved in a file called noncoding_sequence.txt.