(3)
Difficulty Level:
The most important cause of loss of biodiversity today is:
1. habitat loss and fragmentation
2. over-exploitation
3. alien species invasions
4. co-extinctions
The number of species at equilibrium in a smaller area will reduce drastically when compared to a larger area.
Difficulty Level:
(3) Read page 267, XII NCERT
Difficulty Level:
When a threatened plant needs urgent measures to save it from extinction, the desirable approach is
1. in-situ conservation
2. ex-situ conservation
3. cryopreservation
4. biopreservation
(2) Read page 267, XII NCERT
Difficulty Level:
The most important cause of the loss of biodiversity today is the :
1. Habitat loss and fragmentation
2. Over exploitation
3. Alien species invasion
4. Co-extinctions
(1) Read page 264, XII NCERT
Difficulty Level:
Introduction of Lates niloticus led to the extinction of
1. Gambusia
2. Pupfish
3. Cichild fish
4. Chinook salmon
Read page 265, XII NCERT
Lates niloticus is Nile perch.
Difficulty Level:
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
(2) Read page 264, XII NCERT
Difficulty Level:
Which of the following is not a reason that accounts for greater biodiversity of tropics?
1. availability of more solar energy
2. more niche specialization
3. more time for species diversification
4. large seasonal variations in environmental factors
Read page 261, XII NCERT
Difficulty Level:
The greatest biodiversity on the earth is found in
1. African grasslands
2. Amazonian rain forest in South America
3. Western Ghats in India
4. Nile delta in Egypt
(2) Read page 261, XII NCERT
Difficulty Level:
Biodiversity loss is now one of the world's most pressing crises. The primary reason for this is:
1. we cannot do anything about it
2. we are not responsible for this loss
3. we still do not know its entire extent
4. it is affecting only the developing countries
(3) This is the problem. We get lot of direct benefits from biodiversity such as drugs. Only 1.8 million species have been known and described out of estimated 8 million. Imagine what we are losing without aware about it. It is like a library catching fire even before the books are properly catalogued.
Difficulty Level: