Extinction of Stellar’s sea cow and passenger pigeon was due to:
1. | Habitat loss and fragmentation | 2. | Over exploitation |
3. | Invasion of alien species | 4. | Co-extinctions |
What exotic introduction is threatening indigenous catfishes in our rivers?
1. | Carassius auratus | 2. | Carcinus maenas |
3. | Centaurea solstitialis | 4. | Clarias gariepinus |
Introduction of Lates niloticus led to the extinction of:
1. | Gambusia | 2. | Pupfish |
3. | Cichlid fish | 4. | Chinook salmon |
Loss of biodiversity may lead to all except:
1. | decline in plant production |
2. | increased resistance to environmental perturbance |
3. | increased variability in water use |
4. | increased variability in pest and disease cycle |
The main difference between the “Sixth Extinction” and the previous five extinctions is that the sixth extinction:
1. is mainly occurring on islands
2. is mainly affecting plants
3. is occurring at a faster rate
4. does not involve human activities
Which group, amongst the following, has the maximum percentage of species facing threat of extinction?
1. | Amphibians | 2. | Birds |
3. | Mammals | 4. | Gymnosperms |
Which of the following species of tiger has not gone extinct?
1. | Bali | 2. | Javan |
3. | Caspian | 4. | Siberian |
The largest carnivorous marsupial that got extinct in 20th century was:
1. Dodo
2. Quagga
3. Thylacine
4. Stellar’s sea cow
Year-to-year variation shown by areas with more species is ................... with respect to areas with less species.
1. | less | 2. | more |
3. | same | 4. | absent |
The rivet popper hypothesis was given by:
1. | Humboldt | 2. | Ehlrich |
3. | Tilman | 4. | Tansley |