NEET BIOLOGY

Detailed explanation-1: -Entire species permanently disappear from the biosphere when the last member of the species dies in a process called extinction. Many species have become extinct and paleontologists study fossils of those extinct species. The gradual process of species becoming extinct is known as background extinction.

Detailed explanation-2: -The gradual process of species becoming extinct is known as background extinction. Stable ecosystems can be changed by the activity of other organisms, climate changes, or natural disasters. This natural process of extinction is not what scientists are worried about.

Detailed explanation-3: -Background extinction rate, or normal extinction rate, refers to the number of species that would be expected to go extinct over a period of time, based on non-anthropogenic (non-human) factors.

Detailed explanation-4: -In nearly all comparisons of modern versus background extinction rates, the background rate has been assumed to be somewhere between 0.1 and 1 species extinction per 10, 000 species per 100 years (equal to 0.1 to 1 species extinction per million species per year, a widely used metric known as E/MSY).

Detailed explanation-5: -Extinctions occur continually, generating a “turnover” of the species living on Earth. This normal process is called background extinction. Sometimes, however, extinction rates rise suddenly for a relatively short time-an event known as a mass extinction.