During the 1970s, Dr. Carl Woese began to find evidence for a prokaryote that he or other scientists did not previously know existed. The organism lived in very extreme places like the dead sea, hot springs, and in hydrothermal vents. These were soon referred to as archaebacteria because they seemed prokaryotic and like bacteria, however, their DNA was different and they had some different characteristics when compared to bacteria. After more years of research their name changed to Archaea because they were more similar to eukaryotes. Dr. Woese then proposed a new idea, to have domains, and kingdoms underneath the domains. [9]


Archaea-

  • Generally have the same size, shape and appearance as bacteria
  • Multiply by binary fission
  • Move using flagella
  • Walls do not have peptidoglycan
  • Membrane lipids have ether bonds
  • prokaryotic

Bacteria-

  • Multiply by binary fission
  • Move using flagella
  • Walls contain peptidoglycan
  • Membrane lipids have ester bonds
  • prokaryotic

Eukarya-

  • Membrane bound organelles, eukaryotic
  • Membrane lipids have ester bonds
  • Represented by the four kingdoms
  • Nervous system present in kingdom animalia


Domains Quiz- Natan and noah

What is the reason that Archaea was separated into its own domain?





Who was the doctor that founded the three domain system?





Where might organisms from Domain Archaea live?




What does Eukarya have that Archaea and Bacteria do not have?




 
 

Unity and Diversity in the domains

  • Canis lupus familiaris (common house dog), and Canis lupus dingo also known as the dingo

 


Figure 1: puppy

Figure 2: Dingo

  • These 2 different species share many of the same qualities, and this is an example of unity between species. Just because they are not the same species, they still have many of the same characteristics, for example:

○      Both are animals

○      Both have similar look and size

○      Both have similar capabilities and interact with the world in similar ways





  • Streptococcus pyogenes and Quercus rubra

    Figure 3: Streptococcus pyogenes

Figure 4: Acer rubrum

  • These 2 species are examples of disunity between species, meaning that they really have almost nothing in common. They are from different domains, one has only one cell while the other is multicellular, they reproduce differently, and they interact with the outside world differently [11] [12].