Causes of biodiversity loss — practice questions

Question 1 · difficulty L1 · recall

Loss caused when introduced species outcompete or prey on native species:

• A. ecological release only
• B. mutualism
• C. stabilising selection
• D. alien species invasion

Question 2 · difficulty L1 · recall

Loss of one species following extinction of another species on which it obligatorily depends:

• A. gene flow
• B. adaptive radiation
• C. co-extinction
• D. biomagnification

Question 3 · difficulty L1 · recall

The leading cause of biodiversity loss through destruction and breaking up of habitats:

• A. pollination
• B. habitat loss and fragmentation
• C. mutualism
• D. natural selection

Question 4 · difficulty L1 · recall

Unsustainable removal of organisms faster than populations can recover:

• A. co-extinction
• B. gene flow
• C. commensalism
• D. over-exploitation

Question 5 · difficulty L2 · understanding

Match List-I with List-II List - I List - II A The Evil Quartet I Cryopreservation B Ex situ conservation II Alien species invasion C Lantana camara III Causes of biodiversity losses D Dodo IV Extinction Choose the option with all correct matches.

• A. A-III, B-IV, C-II, D-I
• B. A-III, B-II, C-IV, D-I
• C. A-III, B-II, C-I, D-IV
• D. A-III, B-I, C-II, D-IV

Question 6 · difficulty L3 · understanding

Since the origin and diversification of life on Earth, there have been five episodes of mass extinction of species. How is the sixth extinction, which is in progress, different from the previous episodes?

• A. The present net species extinction rate is zero.
• B. The current species extinction rate is nearly 10 times faster than in previous episodes.
• C. The present species extinction rates are 100 to 1000 times faster than in the pre-human times.
• D. The current species extinction rates are far lower than those in previous episodes.

Question 7 · difficulty L3 · understanding

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:

• A. A, B and E only
• B. A, B and D only
• C. C, D and E only
• D. B, C and D only

Question 8 · difficulty L3 · understanding

"The Evil Quartet" of biodiversity loss includes which of the following?

• A. Over-exploitation; Alien species invasions; Air pollution; Co-extinctions
• B. Habitat loss and fragmentation; Air pollution; Water pollution; Co-extinctions
• C. Habitat loss and fragmentation; over-exploitation; Alien species invasions; Co-extinctions
• D. Over-exploitation; Alien species invasions; Soil pollution; Co-extinctions

Question 9 · difficulty L3 · understanding

These are regarded as major causes of biodiversity loss: A. Over exploitation B. Co-extinction C. Mutation D. Habitat loss and fragmentation E. Migration Choose the correct option:

• A. A, C and D only
• B. A, B, C and D only
• C. A, B and E only
• D. A, B and D only

Question 10 · difficulty L3 · understanding

Which of the following is/are cause(s) of biodiversity losses ?

• A. Over-exploitation, habitat loss and fragmentation.
• B. Climate change only
• C. Over-Exploitation only
• D. Habitat loss and fragmentation only