(just answering off the top of my head without looking it up)
Of the non-cell bio-things you mentioned, there’s all a clear reason why they couldn’t be cellular: structural integrity (or extreme lack thereof). That’s not the case with apples (though plausibly the skin works similar to human skin).
Apples ripen in response to ethylene. It’s hard to imagine how that could trigger a complicated ‘ripening’ response throughout the entire apple without cellular machinery. This also makes me believe that the cells throughout must be alive still (at least pre-ripening). When apples first start to go bad, it doesn’t seem like it’s because of mold or bacteria, it just gets mushy in the sort of way I’d expect if the cells were simply dying.
The crispness is most easily explained (to my knowledge) by the stiffer plant cell-walls throughout. It’s not just applesauce inside, there’s something giving it a uniform texture.
And it can’t just be one cell, since that wouldn’t have internal structural integrity to the degree that it does, and also since the seeds, flesh, and skin are clearly different tissues.
I feel pretty confident it’s made of cells.
(just answering off the top of my head without looking it up)
Of the non-cell bio-things you mentioned, there’s all a clear reason why they couldn’t be cellular: structural integrity (or extreme lack thereof). That’s not the case with apples (though plausibly the skin works similar to human skin).
Apples ripen in response to ethylene. It’s hard to imagine how that could trigger a complicated ‘ripening’ response throughout the entire apple without cellular machinery. This also makes me believe that the cells throughout must be alive still (at least pre-ripening). When apples first start to go bad, it doesn’t seem like it’s because of mold or bacteria, it just gets mushy in the sort of way I’d expect if the cells were simply dying.
The crispness is most easily explained (to my knowledge) by the stiffer plant cell-walls throughout. It’s not just applesauce inside, there’s something giving it a uniform texture.
And it can’t just be one cell, since that wouldn’t have internal structural integrity to the degree that it does, and also since the seeds, flesh, and skin are clearly different tissues.