Does a rock have consciousness?

I remember how this was slipped into the last lecture of my intro physiology class.

Now, Nagel reasoned, the properties of a complex system like the brain don’t just pop into existence from nowhere; they must derive from the properties of that system’s ultimate constituents. Those ultimate constituents must therefore have subjective features themselves — features that, in the right combinations, add up to our inner thoughts and feelings. But the electrons, protons and neutrons making up our brains are no different from those making up the rest of the world. So the entire universe must consist of little bits of consciousness.