The function $g(x) = 2^x$ is graphed below on the left, and its derivative $g'(x)$ is graphed on the right.

Write at least one sentence that explains why it is reasonable to think that $g'(x) = cg(x)$, where $c$ is a constant.

Suppose that $g'(0) = 0.6931472$. What is $c$?
$c=$