Primary cultures contain (this cell type) which quickly predominate over the other cell types. Given the proper space and nutrients needed to grow, these cells can divide about 50 times, such that after 50 doublings, an original culture of 100 cells would become cells.

i think it is true in my reasonment ..

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.

i think the answer is composed of atoms