Can anyone help with this question?
Describe three types of evidence that scientists used to develop the three doamin system?
Refer to
http://en.wikipedia.org/wiki/Three-domain_system
for more than three types of evidence. One is differences in 16S rRNA genes of the three domains. Other differences are cell membrane and flagella structure.
To describe three types of evidence that scientists used to develop the three-domain system, we can start with differences in 16S rRNA genes, which are present in all living organisms. The 16S rRNA gene is a part of the ribosomal RNA molecule and its sequence can be analyzed to understand the evolutionary relationships among organisms.
Scientists have compared the sequences of 16S rRNA genes among different species and observed distinct differences between organisms belonging to bacteria, archaea, and eukarya. This evidence suggests that these three groups have diverged significantly from a common ancestor, supporting the idea of three distinct domains of life.
Another type of evidence is the differences in cell membrane structure. The cell membranes of bacteria and archaea are composed of different types of lipids. Bacterial membranes primarily consist of phospholipids, while archaeal membranes contain different types of lipids called isoprenoids. Eukaryotes, on the other hand, have a more complex cell membrane structure, with additional components such as sterols.
Lastly, scientists have also examined the differences in flagella structure among organisms. Flagella are whip-like appendages that certain organisms use for movement. Bacterial and archaeal flagella have a different structure and composition compared to the flagella found in eukaryotes. These differences further support the idea of distinct domains of life.
It is important to note that these are just three examples of evidence used to develop the three-domain system, and there are additional lines of evidence, as mentioned in the provided link to the Wikipedia page. By analyzing the genetic, biochemical, and structural differences among organisms, scientists have been able to classify life into three domains – bacteria, archaea, and eukarya.