5. What country is at the tip of the Persian Gulf?

Gulf of Oman

Basin countriesIran, Iraq, Kuwait, Saudi Arabia, Qatar, Bahrain, United Arab Emirates and Oman (exclave of Musandam)

Explanation:

countries such as spain, france and portugal colonized the region. although most of latin america was colonized by spain, the countries of portugal and france also had major influences on the region. due to war and disease, native populations were decimated.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.