Story related and cannot be missed.
There are 3 memories in DNA Sequence 3, none of which have optional objectives which completing them during your initial run through will help you with another achievement later on.
Memory 1 - A Homecoming
- No optional objective
Memory 2 - Lost Legacy
- No optional objective
Memory 3 - The Message
- No optional objective
Once you complete Memory 3, the achievement should unlock. If you've also completed every optional objective up to this point throughout the main story (DNA Sequences 1-9), then you'll unlock another achievement: