In experiments with two species of paramecia, a scientist proved that two different species cannot both exist in the same area with the same limited resources. This outcome demonstrates what principle? answer choices
intraspecific competition
competitive exclusion
exponential growth
homeostasis

Which best explains how this maneuver unblock a person's airway?

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

Q: a: in sexually reproducing animals, once fertilization of the egg takes place, the exists as a single cell until cell division begins