Q. No.What percentage of total oxygen in the earth’s atmosphere is produced by Amazon rainforest through photosynthesis?
1.
50
2.
40
3.
30
4.
20
The most important cause of the loss of biodiversity today is the:
1. Habitat loss and fragmentation
2. Overexploitation
3. Alien species invasion
4. Co-extinctions
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
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