Assertion : Now-a-days, the biodiversity is declining with an accelerated rate. Reason : Exotic species are considered to be a major cause of extinction of species.

The world is facing accelerated rates of species extinctions, largely due to human interference. There are four major causes (i) habitat loss and fragmentation, (ii) overexploitation, (iii) alien species invasions and (iv) co-extinctions. Non-native of alien species are often introduced inadvertently for their economic and other uses. They often become invasive and drive away the local species. The exotic species are considered to be second major cause of extinction of species (the first being habitat destruction).