C. exocytosis (I have to use 20 characters to respond and "answer it well". Exo means out/outside and exocytosis is an active transport system where a cell uses energy to transport material, like protein or waste, from inside a cell to the outside.)
My answer: Because the actual thing you might be modelling might be too small or large to replicate, (for example you cannot draw a plant cell TO SCALE because it’s way too small to see with a bare eye).
And if the item is too big, you won’t be able to fit it in a small space; if you were to draw it or create it in 3D.
I hope this helps!
Sorry if the response is too short, try rewording if you need to :)
A lot of cells are needed to create a living organism. infinity cells are needed
DNA has 3 components; phosphate, a sugar called deoxyribose (a 5 carbon sugar as opposed to the sugar in the picture which is a 6 carbon sugar - glucose) and a nitrogenous base (adenine, thymine, guanosine or cytosine). So if you look at those 3 pictures, the only one is the nucleotide that's part of the DNA.
Re-read the question: the presence of phosphorous is the answer!!
