Final answer:
Movement in and out of a population occurs in a migrating population through immigration and emigration. Migration can have significant effects on population size and growth rate.
Step-by-step explanation:
Movement in and out of a population occurs in a migrating population. Migration describes the movement of individuals into an area (immigration) or out of an area (emigration) to take up permanent residence elsewhere. Migration can be voluntary, involuntary, or forced, and it can have significant effects on population size and growth rate.