I have often considered all life on Earth as a single organism that’s lived for billions of years so far – basically a kind of ancient slime mold.
I think they’ve actually come up with a name for that notion but I never remember what it is.
For a more restrictive view of life than your professor, “All life has DNA” is an amazing yet standard definition of “life on Earth” which is the only life we know of at present.
That notion of life can be stretched a little to include virii if you think of RNA as being life, as all life=DNA also has RNA. but usually the virus is considered like a proto-life but not life because it needs life as a carrier.
Very much. In fact, the Dewey Decimal System, old classification system for books, has that built-in.
The “01” is usually “Philosophy of”.
So for example:
401: Philosophy of Linguistics/Language
500: General Science
501: Philosophy of Science