Several examples are included for some questions. The conventional view of the origin of eukaryotic cells is often drawn as a tree with single trunk connecting to a root representing the cellular ancestor to prokaryotes and eukaryotes. The complete genome sequences of many eubacteria and archaea are now available.
Evidence now suggests horizontal gene transfer.
During the evolution of eukaryotic cells most mitochondrial genes have moved from the mitochondrial genome to the nuclear genome. The proteins for these genes must now have a signal sequence that will tell them how to get to the mitochondria. You have isolated four different membrane proteins from the new sink organism you discovered. Explain why or why not for each in a sentence. A protein attached to the membrane in such a way does not form a pore and is consequently not an ion channel.