Final answer:
Biodiversity includes the genetic variability within species, the variety of species, and the diversity of ecosystems where these species exist.
Step-by-step explanation:
Biodiversity is more than just the number of species at a site; it also encompasses the diversity of genetic variation within species, the array of different species themselves, and the diversity of ecosystems they form. The genetic diversity is crucial as it equips species with the necessary variation for adaptation to local conditions and changing environments. A well-known example of this can be seen in the numerous varieties of crops that have been cultivated to thrive under specific conditions. Additionally, ecosystem diversity is significant as it represents the breadth of different ecosystems that exist, their unique interactions, and the biological productivity they can yield.