1. Population Growth p

2. Population Growth
Population: a group of the same species living together in a given area
Species: a group of organisms with shared characteristics capable of interbreeding & producing viable offspring
Factors affecting population size:
Birth (natality)
Death (fatality)
Immigration
emigration

3. Three types of population growth:
Exponential Growth
When conditions are ideal for growth & reproduction, a population will increase rapidly, expanding forever unless it is stopped

4. Exponential Growth Curve
* The larger the population gets, the faster it grows
Exponential Growth Curve

5. 2. Logistic Growth
- When a population goes through a number of growth phases:
To start, population grows slowly
Population grows rapidly
Population growth slows down (but is still growing)
Population growth slows down even more
- it is nearing carrying capacity
E) Steady state = although small fluctuations occur, overall population size does not change significantly
F) Carrying capacity = the size of the population during the steady state; limiting factors will prevent population growth

6. F C D E B A

7. 3. Cyclic Growth - when a population cycles up & down between a minimum & maximum population size; never staying at constant carrying capacity

8. Factors Affecting Population Growth
Density Dependent Limiting Factors:
Affect large populations more than small
a) Competition: The struggle for resources between members of the same species & different species.
REMEMBER: No two species can occupy the same niche in the same place at the same time!!

9. b) Predation: - predator-prey relationships can control the natural populations

10. c) Parasitism d) Crowding & stress

11. 2. Density-Independent Limiting Factors a) Weather b) Natural disasters