So if cells need to grow and copy what's on the insides before they can actually split into two new cells (regardless of whether they're reproducing offspring or growing/repairing), they need something to do that...and we're thinking that the stuff they need to grow is what's in blood (food, nutrients, and water).
So using our good 'ol red onion cells, we exposed the cells to both water and saltwater (think nutrients, folks) and we uncovered the following: that the cell grows in size and shrinks in size. This must mean that stuff enters and leaves the cell and the only possibly way it can do so is through the cell membrane/cell wall.
So using our good 'ol red onion cells, we exposed the cells to both water and saltwater (think nutrients, folks) and we uncovered the following: that the cell grows in size and shrinks in size. This must mean that stuff enters and leaves the cell and the only possibly way it can do so is through the cell membrane/cell wall.
Since cell membranes and cell walls are porous/permeable, we're thinking that this is how the dissolved food, water, and nutrients in blood (which is pumped everywhere in our bodies) gets into cells to help them grow bigger, copy what needs copying, and split. In order to do this, the "stuff" that enters the cell must undergo a chemical reaction (as cell parts don't look exactly like the "stuff" that goes into a cell) and releases gas (waste). We're thinking this is how new cells are made!
We've done so much figuring out that it makes sense to put all the pieces together to explain how on earth and egg can become a chicken!