Answer:
For all organisms on Earth to be represented somewhere in the model, it will be necessary for the tree of life to have three branches for the domains: Bacteria, Archea and Eukarya.
Explanation:
For all organisms on Earth to be represented somewhere in the model, it will be necessary for the tree of life to have three branches for the domains: Bacteria, Archea and Eukarya. This is because all living beings, without exception, are embedded in these domains.
In the Archaea domain we find prokaryotic organisms, that is, living beings that do not have a true cell nucleus, in which the genetic material is dispersed in the cytoplasm. In addition, these organisms are single-celled and may have autotrophic or heterotrophic nutrition. Despite being single-celled and prokaryotes, they were separated from bacteria, because, evolutionarily, they are closer to eukaryotes.
In the bacteria domain, organisms are also prokaryotes, unicellular and with autotrophic or heterotrophic nutrition. In this group, there are bacteria already well known to man: those that cause diseases, those that live in soil and water and cyanobacteria.
In the Eukarya domain, all eukaryotic organisms are present, that is, those that have genetic material bounded by a membrane called a nuclear envelope or library. Therefore, in this group, there are protozoa, algae, fungi, plants and animals, therefore, they are single-celled or multicellular organisms with autotrophic or heterotrophic nutrition.