Q1. What is endemism?
Ans: Endemism is the ecological state of being unique to a particular geographic location/area.
Endemic species are species confined only to a limited region.
Q2. Mention ‘The evil quartet’ of biodiversity loss.
Ans:
Habitat loss and fragmentation
Over-exploitation
Alien (exotic) species invasions
Co-extinctions
Q3. 'Invasion of alien species eliminates the native animal species'. Justify the statement by giving any two examples.
Ans: Some alien (exotic) species when introduced unintentionally or deliberately, become invasive and cause harmful impact, resulting in extinction of the indigenous species.
Examples:
Nile perch, a large predator fish when introduced in Lake Victoria (East Africa) caused the extinction of an ecologically unique species of Cichlid fish in the lake.
Invasive weed species like Parthenium (carrot grass), Lantana and Eichhornia (water hyacinth) caused environmental damage and posed threat to our native species.
Introduction of African catfish (Clarias gariepinus) for aquaculture purposes is posing a threat to the indigenous cat fishes of Indian rivers.
Q4. What are Biodiversity hot spots? Give examples.
Ans: These are regions of high levels of species richness and high degree of endemism.
E.g., Western Ghats and Sri Lanka, Indo-Burma and Himalaya.
Q5. What are sacred groves? Give example.
Ans: Sacred groves are the forest patches set aside for worship and all the trees and wildlife within are
given total protection by tribal people.
Some of the sacred groves in India are as follows:
Khasi and Jaintia Hills in Meghalaya
Western Ghat regions of Karnataka and Maharashtra
Aravalli Hills of Rajasthan
Sarguja, Chanda and Bastar areas of Madhya Pradesh.
Q6. What are the two approaches of biodiversity conservation.
Ans:
In-situ conservation and
Ex-situ conservation
❖ In-situ conservation - conservation and protection of wildlife in its natural habitat.
e.g., national parks, biosphere reserves, wildlife sanctuaries, etc.
❖ Ex-situ conservation - conservation of selected threatened plant and animal species in places outside their natural habitat.
e.g., botanical gardens, zoological parks, wildlife safari, gene banks, etc.
Q7. Tropics have greater biodiversity than temperate region. Give reasons.
Ans:
Temperate regions have been subjected to frequent glaciations in the past but tropical regions remained undisturbed. Therefore, tropics had a longer evolutionary time for species diversification.
Temperate environment unlike the tropics are more seasonal, less constant and unpredictable, resulting in less niche specialisation and lesser species diversity.
Tropics have greater solar energy exposure which contributes to higher productivity and greater diversity.
Q8. List out the Characteristics of a stable community.
Ans:
Productivity should not vary too much from year to year.
It should be resistant to occasional natural and man-made disturbances.
It should be resistant to invasions by alien species.