Which of the following loss of rivet will be more crucial for the flight safety?

(1) Loss of rivets on the wings

(2) Loss of rivets on the seats

(3) Loss of rivets on Windows inside the plane

(4) Both A and C

(1) Loss of the key species that drive the major ecosystem functions is a more serious threat to flight safety than loss of other less important species

(2) Proper functioning of ecosystem is initially may not be affected by species loss

(3) Over a period of time, if the species loss is continuous, the ecosystem gets affected after a time

(4) Even the loss of not much significant species lead to crtical damage to ecosystem.

(1) 5000 species of native birds

(2) 2000 species of native birds

(3) 1500 species of mammals

(4) 3500 species of mammals

(1) Vertebrates-338

(2) Invertebrates-359

(3) Plants-87

(4) Bacteria-104

(1) Last 240 years

(2) Last 500 years

(3) Last 300 years

(4) Last 400 years

(1) Dodo-Mauritius

(2) Quagga-Africa

(3) Thylacine-Australia

(4) Steller's Sea Cow- Stanford

(1) Bali

(2) Javan

(3) Caspian

(4) Sumata

(1) 27 species

(2) 40 species

(3) 12 species

(4) 7 species

(1) Some groups like fishes appear to be more vulnerable to extinction

(2) More than 15500 species world-wide are facing the threat of extinction

(3) Presently, 12 per cent of all bird species in the world face the threat of extinction.

(4) Both B and C

(1) Birds-12 per cent

(2) Mammals- 23 per cent

(3) Amphibians- 27 per cent

(4) Gymnosperms- 31 per cent