What triggers cell division?

Putting a mathematician in jail.

The way I understand it, they divide when they reach a certain size and the cell membrane nears a size at which its tension would be dramatically decreased. The availability of sustenance would affect how quickly the cell grew, but not necessarily whether or not it divides. There are certain environments that can promote or retard cell division, but these would be specific to each species. Population density would not have much of an effect, except in the supply and demand of food.

External signals, hormones, growth factors such as proteins able to trigger mitosis.

@mattbrowne, can we synthesize or replicate the factors to trigger the mitosis?

@Trillian – I think so, yes.

The life cycle of a simple amoeba is far from simple. As for your question, most cells (both prokaryotic and eukaryotic) have a predetermined cell cycle (essentially, a stepwise pattern of organizing the DNA synthesis and cell division machinery). Many factors can affect whether cells maintain a constant cell cycle, or arrest it at specific stages. These include the availability of food, signals from other cells, presence of DNA damage, cellular infections by viruses or other agents, and contact with other cells.

I suspected that there would be complications. When I said that the amoeba is simple, I was saying that tongue in cheek. It is extraordinary how complex nature can get. I saw a summary of photosynthesis and it gets very involved. The initial energy capture from the sun is a tiny part of the process.

@Trillian Yes we can. Some drugs used in chemotherapy are designed to target cancer cells and prevent their replication. One of my lecturers has done research into proteins that retard cell division, with a view to creating a drug to make people less radiosensitive before large radiation doses. We can probably initiate replication too, although I am not aware of a specific drug or a potential use.

will power.

Internal dissension.