I know that growth is an irreversible increase in mass or overall size of a cell, organ or whole organism. I also found that growth occurs due to the net result of anabolism and catabolism. My teacher said; When anabolism > catabolism - growth occurs Anabolism = catabolism - no growth Catabolism > anabolism - negative growth But on searching about this negative growth, I couldn't find any information. What is this negative growth? Where do you see it?
When you look at a certain mass of cells (in a petri dish, a tumor, whatever) which are in principle viable, growth can go in both directions. It can be poitive which means that the number of cells is growing over time.
It can also be negative, which results in a declining number of cells over time. We see this effect in cell growth assays, when we analyze the effect of certain treatments to our cells. Since we want to "kill" our cells with the treatment, a positive growth would indicate an unsuccessful treatment, a negative cell growth a positive treatment effect.