I mean, correct me if I’m wrong, but IIRC cell size is mostly determined by the necessary rate of diffusion across the membrane and the surface area to volume ratio for a given size.
So, while there are some extreme outliers with more exotic cell biology, organisms having similar cellular metabolisms will generally have similarly sized cells, at least within an order of magnitude. Or in other words, an elephant is much larger than an ant because it has many more cells, not because its cells are much larger.
An exception to this of course being neural cells, which can be very very long, or very wide and branched (like Purkinje cells). But even within the brain this still kinda holds true. I actually know much more about brain anatomy than general biology, and I remember from the book Principles of Brain Evolution that elephant brains are much larger than ours, and actually have a much larger number of neurons, and that strangely intelligence seems to correlate more with the ratio between brain and body size than with absolute brain size. A possible explanation is that it may simply take a larger number of neurons to coordinate a larger number of muscle cells.
EDIT: case in point C. Elegans is about 1mm (or 1000 μm) long and has 1031 cells, including 302 neurons, which lines up with its cells being about as large as human cells when you consider that its a 3D volume and not a single chain of cells lined up next to each other.
Definitely wrong, although I do not have a collegiate off-hand understanding of biology to really fully decribe it.
But it comes down to what does a “cell” mean in biology? Even your case in point specifies an object with many cells in it.
Cell membranes don’t use simple diffusion to transport chemicals across. That’s the entire point of a “cell”. It’s a defined region that at least attempts to control its own various chemical balances. Cells do have many gates that allow many molecules across, unfortunately including many viruses and prions. Unfortuntely, cell walls are also not impervious to truly toxic chemicals, either, so a “cell wall” still can absolutely break down with minimal effort with the right chemicals. They do attempt to control their own balances though, including basic ionic content. That’s the whole point. The attempt.
I really have to ask… Why do you think humans aren’t so big on the scale of life? Your perspective really come across as human-centric. Not “bad” by itself, but still wholly incompatible with reality.
The thing that does change in relation to diffusion at scale is the necessity of circulatory and respertory systems, which is a massive order of magnitude or few increase in complexity than cells.
Definitely wrong, although I do not have a collegiate off-hand understanding of biology to really fully decribe it.
Well, from reading this its pretty clear to me now that you don’t know much about biology. And yet you have really strong opinions on something you have no education in.
But it comes down to what does a “cell” mean in biology? Even your case in point specifies an object with many cells in it.
What are you even trying to say here?
Cell membranes don’t use simple diffusion to transport chemicals across.
They do for quite a lot things actually. Simple diffusion, facilitated diffusion, and active transport all take place and are all necessary for the cell to function. The ratio of cytoplasm volume to cell membrane area is relevant regardless.
By the way, you didn’t need to write an entire paragraph about homeostasis or try to define what a cell is.
I really have to ask… Why do you think humans aren’t so big on the scale of life? Your perspective really come across as human-centric. Not “bad” by itself, but still wholly incompatible with reality.
Your perspective really comes across like you’re high on something. You also apparently didn’t understand what my comment was even about. It was about this sentence:
You are assuming a red blood cell is a common size
I wasn’t assuming anything. In saying “correct me if I’m wrong” I was being charitable in leaving the door open that you might know something relevant about cellular scale that I didn’t. But I’m pretty confident now that is not the case.
I mean, correct me if I’m wrong, but IIRC cell size is mostly determined by the necessary rate of diffusion across the membrane and the surface area to volume ratio for a given size.
So, while there are some extreme outliers with more exotic cell biology, organisms having similar cellular metabolisms will generally have similarly sized cells, at least within an order of magnitude. Or in other words, an elephant is much larger than an ant because it has many more cells, not because its cells are much larger.
An exception to this of course being neural cells, which can be very very long, or very wide and branched (like Purkinje cells). But even within the brain this still kinda holds true. I actually know much more about brain anatomy than general biology, and I remember from the book Principles of Brain Evolution that elephant brains are much larger than ours, and actually have a much larger number of neurons, and that strangely intelligence seems to correlate more with the ratio between brain and body size than with absolute brain size. A possible explanation is that it may simply take a larger number of neurons to coordinate a larger number of muscle cells.
EDIT: case in point C. Elegans is about 1mm (or 1000 μm) long and has 1031 cells, including 302 neurons, which lines up with its cells being about as large as human cells when you consider that its a 3D volume and not a single chain of cells lined up next to each other.
Definitely wrong, although I do not have a collegiate off-hand understanding of biology to really fully decribe it.
But it comes down to what does a “cell” mean in biology? Even your case in point specifies an object with many cells in it.
Cell membranes don’t use simple diffusion to transport chemicals across. That’s the entire point of a “cell”. It’s a defined region that at least attempts to control its own various chemical balances. Cells do have many gates that allow many molecules across, unfortunately including many viruses and prions. Unfortuntely, cell walls are also not impervious to truly toxic chemicals, either, so a “cell wall” still can absolutely break down with minimal effort with the right chemicals. They do attempt to control their own balances though, including basic ionic content. That’s the whole point. The attempt.
I really have to ask… Why do you think humans aren’t so big on the scale of life? Your perspective really come across as human-centric. Not “bad” by itself, but still wholly incompatible with reality.
The thing that does change in relation to diffusion at scale is the necessity of circulatory and respertory systems, which is a massive order of magnitude or few increase in complexity than cells.
Well, from reading this its pretty clear to me now that you don’t know much about biology. And yet you have really strong opinions on something you have no education in.
What are you even trying to say here?
They do for quite a lot things actually. Simple diffusion, facilitated diffusion, and active transport all take place and are all necessary for the cell to function. The ratio of cytoplasm volume to cell membrane area is relevant regardless.
By the way, you didn’t need to write an entire paragraph about homeostasis or try to define what a cell is.
Your perspective really comes across like you’re high on something. You also apparently didn’t understand what my comment was even about. It was about this sentence:
I wasn’t assuming anything. In saying “correct me if I’m wrong” I was being charitable in leaving the door open that you might know something relevant about cellular scale that I didn’t. But I’m pretty confident now that is not the case.