I’m currently learning about DNA replication in both prokaryotic and eukaryotic cells. And my lecturer has mentioned that replication is a once in a lifetime activity. And I’m not sure what this is implying because I’ve searched up that DNA replication occurs during cell division (cell cycles), which occur repetitively as organisms develop.
This sounds like a difference in perspective of when exactly cells "die". If you consider that, in a cell division, a mother cell "gives birth" to two daughter cells, you could argue that the mother cell has "died". It makes sense to think about cell division in this way because it puts both daughter cells in the same level, without one being "special" due to it being the mother cell itself while the other is considered the "new cell".
If you face cell division like this, any cell (eukaryote or procaryote) will only really duplicate their DNA once: they duplicate their DNA -> they split into daughter cells, in which they "die" -> (eventually) each daughter cell duplicate their DNA -> and so on.
Like I said this is just a particular POV we can adpot when we try to understand and describe cell cycle and cell division (although it is a common one for researchers in the field).