The “three-domain system,” developed by Carl Woese in 1990, is currently the most accepted system for classifying biological organisms.

Image to the left is Giardia lamblia. The Protista kingdom is a diverse group of eukaryotic organisms that are neither plants, animals, nor fungi. Often serving as a “catch-all” category for microorganisms that don’t fit neatly into other kingdoms.

This is the taxonomic kingdom that includes all animals; from animal cells to multicellular animal organisms.

This is the taxonomic kingdom that covers plant cells, green algae cells, and multi-cellular organisms made from these two types of cells.

Image to the left is an aggregation of yeast cells. The taxonomic kingdom of Fungi include uni-cellular organisms (yeast cells, hyphal cells, and spore-producing cells), and multi-cellular organisms (mushrooms and certain molds that do not fit in the Protista kingdom).

This section covers 1) Replication mechanisms of cells, 2) Respiration mechanism of cells, 3) Nutrient consumption mechanisms of cells, and 4) The central dogma of molecular biology.