The could tell by solar radiation and dark matter, they didnt know were dark matter was but they new it was there
With the actions of the humans the biodiversity is facing a huge problem in most of the world, the habitats are destroyed, forests are cleared, animals are killed, water and air are polluted...
In order to conserve the biodiversity there are certain things that have to be put in action. The methods for conservation can be in-situ methods and ex-situ methods.
The in-situ methods are the preferred ones, as these methods are focused on conserving the environment as it is. This basically means that the ares that have larger biodiversity, and especially where there's species that are rare, should be made national parks, sanctuaries, monuments of nature, thus being protected by law.
The ex-situ methods are the ones that involve the conservation of the species outside of their natural habitat. That is done with gene banks, sperm and ova banks, seed banks, zoos and botanical gardens, collections of In vitro plant tissue and microbal culture, and captive breeding of animals and artificial propagation of plants.
OmposingFossils in the museums are coated with chemicals to prevent the bones from decomposing.
c is the answer to your question
Denitrification is the major process involved in converting nitrogen components present in the nitrogen gas and it is released into the atmosphere.
<u>EXPLANATION: </u>
With the help of the nitrogen cycle, the nitrogen that enters living things by nitrogen fixation is converted back into nitrogen and is released in the atmosphere by microbes.
The nitrogen-fixing bacteria converts the nitrogen contents into ammonia by the process called ammonification. Then it oxidizes ammonia to nitrite by the process called nitrification and these nitrates are absorbed by plants.
Then, the bacteria present in the soil convert nitrate back to nitrogen gas which is released back to the atmosphere.