Say which of these grow from inside, like a living thing, and which grow by material that piles up…

Growth is an increase in mass and in the number of cells. A living thing grows from inside, by cell division; a non-living thing grows only by material added on its outside. Plants grow all their life, animals up to a certain age. In a one-celled organism, growth and reproduction are one event: after $n$ divisions, one cell gives $2^n$.