If you're seeing this message, it means we're having trouble loading external resources on our website.

Hvis du er bak et webfilter, vær vennlig å sørge for at domenene .kastatic.org og .kastatic.org ikke er blokkert.

Learn about the basic properties of life as well as ongoing debates about the definition of life.
Sorter etter:
Biology is brought to you with support from the Amgen Foundation