Answer: A. before history was written.
Explanation:
I'm not sure if you need an explanation, but prehistoric means "very old or out of date." Hope this helps, Good luck! :)
They all contain carbonyl groups. DNA has carbonyl groups in it's nucleotide ring structures. Every amino acid in a protein has a carbonyl group in its backbone structure. Fats too have carbonyl groups in their structures attached to hydrocarbon chains
If I’m Not Mistaking Your Answer Will Be...
Gene Flow
Answer:
A protein isoform, or " protein variant ", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have unique functions.
Explanation: