The causes of biodiversity loss are:(A) Habitat loss(B) Invasion of a…

The correct answer is Option (2) → (A), (B) and (C) only

NCERT names four major causes of biodiversity loss, called ‘The Evil Quartet’: habitat loss and fragmentation, over-exploitation, alien species invasions and co-extinctions.

(A) Habitat loss — A cause. It is the most important cause. Tropical rain forests once covered more than 14 per cent of the earth’s land and now cover no more than 6 per cent.

(B) Invasion of alien species — A cause. Some species brought in from outside turn invasive. The Nile perch in Lake Victoria wiped out more than 200 species of cichlid fish.

(C) Co-extinction — A cause. When a species dies out, species tied to it in an obligatory way also die out, such as a host fish and its parasites.

(D) Endemism — Not a cause. An endemic species is one found only in a particular region. High endemism is a reason to protect an area, as in the biodiversity hotspots; it does not destroy species.

NCERT Extract:
Loss of Biodiversity – “… Causes of biodiversity losses: The accelerated rates of species extinctions that the world is facing now are largely due to human activities. There are four major causes (‘The Evil Quartet’ is the sobriquet used to describe them).
(i) Habitat loss and fragmentation: This is the most important cause driving animals and plants to extinction.”
Loss of Biodiversity – “… (iii) Alien species invasions: When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive, and cause decline or extinction of indigenous species.”
Loss of Biodiversity – “(iv) Co-extinctions: When a species becomes extinct, the plant and animal species associated with it in an obligatory way also become extinct. When a host fish species becomes extinct, its unique assemblage of parasites also meets the same fate.”