Our Universe is bigger, than a galaxy.
Yes, a galaxy is much larger than the moon. A galaxy is a system of stars, gas, dust, and dark matter held together by gravity, while the moon is Earth's natural satellite that orbits around it. The Milky Way, which is the galaxy that contains our solar system, is estimated to be billions of times larger than the moon.
Obviously, the Universe is the biggest of that lot. Next biggest is "galaxy", then solar system, then star, then moon. A comet is usually bigger than a meteorite, but not always.
A Galaxy is far bigger than a nebula.
No!
No.
A galaxy cluster consists of several galaxy groups, each of which in turn contains several galaxies. So no; a galaxy cluster is MUCH bigger than any individual galaxy.
No. The Milky Way is our Galaxy.
A dwarf galaxy by virtue of it's name will be smaller than a "normal" galaxy.
Nope! It's smaller than the S3.
No.
If the moon was bigger than the Earth, than Earth would orbit it and, by our current definitions, it would be a moon.