Table 7a-1 describes the approximate time of origin of the Earth' s major groups of plants and animals. Time of origin of some major plant and animal groups. Archaea are single-celled organisms that are similar in appearance to bacteria . However, they are biochemically and genetically very different from bacteria. Many books and other forms of scientific literature refer to them as archaebacteria .
Bacteria have a prokaryote cell type.
They also generally obtain energy for survival through the breakdown of organic matter via fermentation and respiration . Bacteria such as Rhizobium spp. Without these bacteria ecosystems would be severely short of nitrogen for plant and animal growth. The oldest fossils of life on Earth are bacteria-like organisms. Eukaryota - are all organisms with a eukaryote cell type.