Should be called the Manubrium!
Eukaryotes have a nucleus with a membrane, larger ribosomal subunits, usually reproduce sexually, and may not have a cell wall. Prokaryotes have no membrane around the nucleus, smaller ribosomal subunits, reproduce asexually, and do have cell walls.
Direct observation is an observation you make first hand. It is something you see with your own eyes and observe yourself.
Hope this helps!
