What does the term "biodiversity" refer to?

The term "biodiversity" encompasses the variety of life in the world or in a specific habitat or ecosystem. This definition is comprehensive, as it includes not only the different species present, but also genetic variations within those species, and the ecosystems they form. Biodiversity is crucial for ecosystem resilience, providing essential services such as food production, water filtration, and climate regulation. Focusing on the variety of life highlights the intricate relationships between species and emphasizes the importance of conserving various habitats to maintain this biological richness.

The other options touch on important aspects of life and ecosystems but do not fully capture the broader and more inclusive meaning of biodiversity. For instance, while the range of different species is a significant component, it does not take into account the genetic diversity or the interactions within ecosystems. Similarly, counting the total number of organisms or discussing ecosystem richness misses the vast complexity and interdependence of life forms that define biodiversity in its entirety.