Q95
neet_2026_03_may_morning
Loss of Biodiversity
Which of the following statements are correct?
A. The Amazon rainforest being cut and cleared for cultivation of soyabeans is an example of habitat loss.
B. Steller's sea cow and passenger pigeon became extinct due to over-exploitation by humans.
C. The Nile perch introduced into Lake Victoria in East Africa helped in population growth of cichlid fish in the lake.
D. Water hyacinth is an invasive species.
E. When a species becomes extinct, the plant and animal species associated with it are not affected.
Choose the correct answer from the options given below:
Solution
Core Logic
Let's evaluate each statement:
- Statement A is correct. Clearing the Amazon for soyabeans represents severe habitat loss and fragmentation.
- Statement B is correct. Over-exploitation by humans in the last 500 years led to the extinction of Steller's sea cow and the passenger pigeon.
- Statement C is incorrect. The introduction of the Nile perch into Lake Victoria led to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake, not their population growth.
- Statement D is correct. Water hyacinth (Eichhornia) is a notorious invasive alien species.
- Statement E is incorrect. When a species becomes extinct, the plant and animal species associated with it in an obligatory way also become extinct (this is known as Co-extinction).
Step 1: Final Conclusion
Only statements A, B, and D are correct.
Pattern Recognition
Alien species introduction usually causes extinction (Nile Perch → Cichlid fish death), not population growth. Recognizing C is false immediately eliminates options 1 and 4. Recognizing E is false (due to co-extinction) eliminates option 3.
Chapter Mix
Class 12 Biology: Biodiversity and Conservation
