Final answer:
Mutation-induced variation is maintained by post-translational modifications and splicing, which are crucial for altering protein functions and increasing genetic diversity. The correct answer is option D.
Step-by-step explanation:
Variation by mutation is maintained through post-translational modifications and splicing changing the final protein. The correct option here is D) Post-translational modifications; Splicing. Post-translational modifications are changes that proteins undergo after synthesis, which can alter their function, stability, localization, or interactions with other proteins. Splicing, on the other hand, is a process where introns are removed and exons are joined to form a mature messenger RNA (mRNA) transcript that dictates the protein synthesis during translation.
Mutations are indeed random changes in DNA sequence, which can create genetic diversity. They may occur spontaneously or as a result of environmental factors. During transcription, RNA polymerase copies DNA into RNA, sometimes introducing errors that can lead to variations.
The role of splicing is also essential as it can produce different protein variants from the same gene. This, along with post-translational modifications, contributes to the complexity and adaptability of organisms by allowing a single gene to produce multiple functional proteins that can perform various roles within a cell or organism.