Answer:Transcriptional Regulation
Explanation:
Eukaryotic gene expression can be regulated during the time of transcription and RNA processing, which takes place in the nucleus of the cell and then during the time of protein translation in the cytoplasm.
Further regulation is being carried during the time of post transnational modification. The conservation of energy is very important because it saves the overall energy and space in the body.
Hence, the most important point for the regulation would be transcriptional regulation.
Answer;
A) island forms and mainland forms descended from common ancestors.
Explanation;
-Islands tend to host very distinct but limited sets or species; on a given island a spectacular collection of one related group of species would be present and thriving, but many entire families or even higher taxa would be completely absent.
-All the species on the islands and the nearest continent are closely related to one another, however, each species had a set of adaptations that suits it for a particular environment. This means that the island forms and mainland forms descended from common ancestors.
The question is asking the determine the role that the United States do in the ecosystem base on the passage and situation in the question that you have state, base on my research, I would say that its role is a Dominant. I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarification
