1. Populations and Communities Living Things and the Environment

2. A little vocab…  Ecology - the study of how organisms interact with their environment  Organism - a living thing  Habitat - the specific environment that provides the things an organism needs to live, grow, and reproduce

3. Living or Nonliving?  Biotic Factor - living parts of a habitat –Examples - flowers, worm, frog  Abiotic Factor - nonliving part of a habitat –Examples - water, sunlight, oxygen

4. The Line-Up  Species - group of organisms that mate and reproduce  Population - all members of one species in a particular area  Community - all different populations that live in an area  Ecosystem - a community including its surrounding environment (abiotic factors)

5. Populations and Communities Studying Populations

6. Types of Observations  Direct Observation - counting all individuals by ones  Indirect Observation - counting the “signs” of an individual

7. Methods of Study  Sampling - taking an estimate of a type of organism in an area  Mark-and-Recapture Studies - catch an organism, mark it, then release  Total Population = Number of Marked X Total Number Captured Number Recaptured with Marks

8. Population Fluctuation  Birth Rate - # of births in a population during a specific time  Death Rate - # of deaths in a population during a specific time If birth rate is > than death rate, then population is ____________ If birth rate is < than death rate, then population is ____________

9. Population Fluctuation  Immigration - organisms moving into a population  Emigration - organisms moving out of a population Population Growth Equation: (B - D) + (I - E) = N *If N is a positive #, the population is increasing

10. Population Fluctuation  Population Density - # of individuals in a specific area Population Density Equation: # individuals Unit area

11. Population Factors  Limiting Factor - an environmental factor that causes a population to decrease –Examples: food and water, space and weather  Carrying Capacity (K) - the largest population that an area can carry

12. Populations and Communities Interactions Among Living Things

13. A Place in the World  Adaptations – a physical characteristic that helps an organism live in an area –Example: cacti in the desert  Niche – the role of an organism in its habitat, or how it makes its living –type of food I eat –Who else eats you –Whether you need to survive

14. The Fight  Competition – the struggle (fight) between two organism to get the same thing

15. Let’s Eat!  Predation – when one organism kills another for food –Predator – dominant organism  Predator Adaptations – help them catch and kill their prey –Prey – inferior organism  Prey Defense Strategies – certain adaptations to prevent being killed by predators –Skunk, poison ivy, porcupines

16. Relationships  Mutualism – both species benefit –Example – hippo and bird  Commensalism – one species benefits and the other is neither helped nor harmed –Example – clown fish and sea anemone  Parasitism – one species is benefited and the other is harmed. Doesn’t kill because it needs the host to live –Example – head lice, ringworm, tape worm, ticks

17. Relationship Species One Species Two Mutualism++ Commensalism+O Parasitism+-