What limits the size of living organisms? Specifically in relation to cells?

Question

What limits the size of living organisms? Specifically in relation to cells?

Answer 1

Well for most animals we know stuff like their blood couldn't pump through a body the size of a mansion. If an animal evolved maybe multiple systems in a single body then theoretically there is no limit. At that point though it may be less of an organism and more of an Eco-system. Coral reef is an example of a similar process taking place.

Answer 2

Let's put this in normal terms:

When a cell grows, eventually it will have to either

divide or stop growing. They get too big that it is

too hard to get water and nutrients across the membrane.

They just simply get too big and it's harder for them to

survive, so they then divide.

Answer 3

It's the ratio of surface area to volume.  If individual cells or the organism as a whole grow too large, the organism will have a much greater volume relative to its surface area.  As a result, vital functions that take place only at the surface of the organism, such as respiration and secretion, cannot happen at a sufficient rate to sustain metabolic processes taking place inside the organism's volume.