these are the mitochondria and chloroplasts and it is because they have their own DNA, mRNA, tRNA, ribosomes and they replicate by binary fission so they are said to be self governing. Semi autonomous means they want to leave but they are in a symbiotic relationship with the cell and have evolved to become part of it.
Organs are made up of tissues, which are made up of cells. Cells are "living things," so yes, organs are living.