It is defined as the end of a group of organisms or species.

It forms when sulfur dioxide and/or nitrogen oxides are released into the atmosphere from volcanic eruptions and other biological processes.

These are the foreign organisms that encroach the territory of species native to a particular location.

It refers to the illegal act of capturing non-domesticated animals. 

It refers to the loss of a large percentage of species in several places.

Why are African Elephants being poached?

Which country is said to have the highest number of endangered species in the world in 2013?

Which of the following is the primary effect of acid rain?

An endangered species is ___________________ that will become extinct if its populations continue to decline. 

This refers to a phenomenon in which a certain species that was presumed extinct has been re-discovered in another place.