2. Population 3 Important Characteristics of a Population 1.Geographic Distribution (Range) - the area inhabited by a population - example: whales occupy millions of square kilometers in the Pacific Ocean when migrating 2.Population Density -the number of individuals per unit area -Example: the population of saquaro cactus have a low density 3.Growth Rate 3 factors:

3. a. Number of births -population can grow when its birthrate is greater than its death rate b.Number of deaths c.Number that enter or leave - immigration – movement of individuals into an area - emigration – movement of individuals out of an area animals tend to do this in search of mates or food

4. If a population has abundant space and food, and is protected from predators and disease, then organisms will multiply. Exponential growth – individuals in a population reproduce at a constant rate; under ideal conditions with unlimited resources, a population will grow exponentially exponential growth # of bacteria is represented by a J curve Time(hours) Carrying capacity – the largest number of individuals that a given environment can support

5. Things that could limit population size would include: competition, predation, parasitism, disease, climate conditions, and human disturbances