Smaller galaxies do. Larger galaxies contain billions or even trillions of stars.
None. Galaxies on the other hand do contain planets
Spiral and irregular galaxies.
Yes. Some spiral galaxies do contain at least 1 trillion stars.
Yes. Some dwarf galaxies contain at least 1 billion stars.
No one knows for sure but it will be in the billions.
quasars.
quasars.
quasars.
Yes. Some giant elliptical galaxies contain tens of trillions of stars.
Galxies were once thought to be nebulaes
(Atoms) Stars, Dust.