Certain species of what are now recognized as indicators of environmental pollution

The correct answer is lichens.

Explanation:

Lichens are a symbiotic association between the fungi and algae. The lichens are bioindicators, that is, they are very subtle to atmospheric pollution like nitrogen as they obtain all their water and nutrients from dry and wet atmospheric deposition. The deposition of nitrogen can enhance the nutrients load.  

Some of the species of lichens are more forbearing to nitrogen in comparison to others. The communities of lichens are monitored by the scientists, that is, if an enhancement in nitrogen tolerant species in association with a reduction in nitrogen sensitive species takes place, it suggests that there is an elevation in atmospheric nitrogen deposition.  

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

1. desertification

2. captive breeding

3. black rhinoceros

4. renewable resources

explanation:

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