One issue facing science surrounds loss of , mainly in the form of , or the complete elimination of a species or larger group.

1. Biodiversity

2. Extinction

Explanation:

Biodiversity refers to the variety of living organisms present on the Earth. The biodiversity on earth is lost at an alarming rate as a result of the anthropogenic activities.

The loss of biodiversity in ecology refers to the loss of the living species or extinction of the species.

The extinction of species is a natural process when the species fails to adapt to the changing climatic conditions but the extinction of species has increased after the industrial revolution due to the drastic changes in the climatic conditions. The species are not able to cope up and adapt to the changes and thus are disappearing from the Earth.

Thus, Biodiversity and Extinction are correct.