Major Causes of Species Loss — NEET Biology

Correct answer: B — S1 and S4 only

Let's evaluate each statement: S1: Habitat loss and fragmentation is indeed the most important cause driving animals and plants to extinction, with the Amazon rainforest clearing for soy cultivation being a dramatic example. This statement is correct according to NCERT. S2: The extinction of Steller’s sea cow and passenger pigeon was due to over-exploitation by humans, not alien species invasion. Thus, this statement is incorrect. S3: The introduction of the Nile perch into Lake Victoria is a classic example of alien species invasion leading to the extinction of indigenous cichlid fish, not co-extinction. Thus, this statement is incorrect. S4: Co-extinction occurs when a species becomes extinct, and another species obligatorily associated with it also vanishes. The extinction of an obligate plant species leading to the loss of its pollinator is a direct example of co-extinction. This statement is correct. S5: Degradation of habitats by pollution and fragmentation of large habitats are integral aspects and examples of habitat loss and fragmentation, not distinct causes separate from it. Thus, this statement is incorrect. Therefore, statements S1 and S4 are correct. The correct option is B.