The three-domain system is a biological classification introduced by Carl Woese et al.in 1977[1][2] that divides cellular life forms into archaea, bacteria, and eukaryote domains. In particular, it emphasizes the separation of prokaryotes into two groups, originally called Eubacteria (now Bacteria) and Archaebacteria(now Archaea). Woese argued that, on the basis of differences in 16S rRNA genes, these two groups and the eukaryotes each arose separately from an ancestor with poorly developed genetic machinery, often called a progenote. To reflect these primary lines of descent, he treated each as a domain, divided into several different kingdoms. Woese initially used the term "kingdom" to refer to the three primary phylogenic groupings, and this nomenclature was widely used until the term "domain" was adopted in 1990.[2]
Parts of the three-domain theory have been challenged by scientists such as Radhey Gupta, who argues that the primary division within prokaryotes should be between those surrounded by a single membrane, and those with two membranes.
Answer:
See explanation
Explanation:
The tympanic membrane or eardrum serves as a divider between the outer ear and the middle ear structures. It is gray-pink in color when healthy and consists of three very thin layers of living tissue. The eardrum is very sensitive to sound waves and vibrates back and forth as the sound waves strike it.
The body already produces enough protein to get by just fine. However, many people think athletes "use up" too much protein and faster than they gain it back, but that is not true because the body regulates homeostasis. I hope I helped :)
10, I guess. Thank you for the free points.
