Assertion : estimate given by IUCN for biodiversity do not give any figures for prokaryotes.
Reason : Biologists are not sure about how many prokaryotic species there might be.

Biologists are not sure about how many prokaryotic species there might be. The problem is that

Biologists are not sure about how many prodaryotic species on earth might be present. The problem is that

Assertion: There is no clearcut estimation about biodiversity of prokaryotes. Reason:- Conventional taxonomic methods are not suitable for identification of microbes and many species are not culturable.

Assertion: There is no clearcut estimation about biodiversity of prokaryotes. Reason:- Conventional taxonomic methods are not suitable for identification of microbes and many species are not culturable.

Assertion (A) : Blue green algae are prokaryotes. Reason (R) : They do not have a true nucleus.

Assertion : About the total number of species present on earth some extreme estimate range from 20 to 50 million. Reason : We have no clear idea of how many species are yet to be discovered and described.

Assertion : Bacteria are prokaryotic. Reason : Bacteria do not posses true nucleus and membrane bound cell organelles.