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

Subtopic:  Importance of Biodiversity |
 70%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


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

Subtopic:  Loss of Biodiversity |
 90%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


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
Subtopic:  Loss of Biodiversity |
 80%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


What exotic introduction is threatening indigenous catfishes in our rivers?

1. Carassius auratus 2. Carcinus maenas
3. Centaurea solstitialis 4. Clarias gariepinus
Subtopic:  Loss of Biodiversity |
 85%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


Introduction of Lates niloticus led to the extinction of:

1.Gambusia2.Pupfish
3.Cichlid fish4.Chinook salmon

Subtopic:  Loss of Biodiversity |
 71%

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


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

Subtopic:  Loss of Biodiversity |
 70%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


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

Subtopic:  Loss of Biodiversity |
 84%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


Which group, amongst the following, has the maximum percentage of species facing threat of extinction?

1.  Amphibians 2.  Birds
3.  Mammals 4.  Gymnosperms
Subtopic:  Loss of Biodiversity |
 75%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


Which of the following species of tiger has not gone extinct?

1.  Bali 2.  Javan
3.  Caspian 4.  Siberian
Subtopic:  Loss of Biodiversity |
 87%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.


The largest carnivorous marsupial that got extinct in 20th century was:
1. Dodo
2. Quagga
3. Thylacine
4. Stellar’s sea cow

Subtopic:  Loss of Biodiversity |

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.