Most of them.
Essentially – all bacteria and single celled organisms.
They all divide at some point, but both the cells that result from the division are essentially the same (some minor variation, but nothing approximating the cellular senescence we see in more complex life forms).
The default mode of life for all cells is indefinite.
Even in complex organisms, if you consider the germ line, it is very old, indefinitely viable.
Senescence (loss of function with age) seems to come with differentiation of function in cell lines in complex organisms.
Simple organisms age, but do not show loss of function with age.
The loss of function with age is only seen in complex organisms.
It seems to be part of how we got to be complex (it allows for rapid evolution). The things that don’t do it are still relatively simple. And of course is it more complex than that over simplification implies – and it does seem to be part of the picture.
