1. Populations: Growth and Limiting Factors

2. Populations A group of organisms of the same
species living together & can interbreed
Grow:
Exponentially ~ numbers increase by a certain factor
Ex: 1 min = 2 bacteria, 2 min = 4 bacteria, 3 min = 8 bacteria
Logistically ~ start w/ low number, then reaches a maximum based on carrying capacity
Ex: 24 rabbits continue to reproduce until resources become low, then reproduction slows
Carrying capacity ~largest population an environment can any time (Density independent & dependent)

3. Factors affecting population
Biotic ~ living & factors related to the activities of living things. Ex: disease, food, parasites, starvation, predators.
Density dependent
Abiotic ~ nonliving factors. Ex: weather, water, temperature, climate.
Density independent

4. Population interactions
Pops interact to survive & maintain equilibrium
Symbiosis ~ a close association of two species
Predator/Prey interaction
Predation ~ killing an organism for food
Predator ~ kills, prey ~ is /gets killed
Parasite/Host interaction
Parasitism ~ one organism feeds on another organism
Parasite ~ feeds on organism, host ~ gets fed off of
**** COEVOLUTION****

6. POPULATION INTERACTIONS
Mutualism
Relationship where both species benefit
Commensalism
Relationship where one species benefits & the other is neither harmed nor helped

7. Populations
Population Density: # of individuals in a specific area at a given time
Biodiversity: having a variety of organisms in a specific area

8. Population Growth Population Size is affected by # of births
# of deaths
migration

9. Exponential Growth (J Curve)
the population continues to increase because there are unlimited resources

10. Logistic Growth (S curve)
Population growth slows as it reaches carrying capacity
Carrying capacity = the # of individuals that the environment can support

12. A look into Communities
Every organism has a role or niche
Fundamental ~ conditions that organism could survive
Realized ~ conditions actually surviving
Similar niches result in competitive exclusion
One species eliminates another thru competition
**Some species will divide resources**

13. A look into communities
It is important to remember:
Ecosystems thrive due to much biodiversity
All organism work with other organisms to maintain equilibrium.
All organisms play a role that helps to maintain the ecosystem. If one part of the ecosystem changes, so does the entire ecosystem!