Organisms are classified into three domains: Archaea, Bacteria, and Eukarya.
Scientists compared several molecular and cellular features across these three domains.
The table shows a comparison of some features of the three domains:
| Feature | Archaea | Bacteria | Eukarya |
|---|---|---|---|
| Peptidoglycan in cell wall | Absent | Present | Absent |
| RNA polymerase | Several types | One type | Several types |
| Initiator amino acid for translation | Methionine | Formyl-methionine | Methionine |
| Membrane lipid structure | Ether-linked | Ester-linked | Ester-linked |
| Introns in genes | Present in some | Absent | Present in most |
Explain what conclusions can be drawn from the table about which domains are most closely related.
State the roles of RNA polymerase and tRNA in cells.