Interactions of Living Things!! Everything is connected!!!! Vocabulary….

Ecology From the Greek “oikos” meaning house or place to live. Ecology is the study of the interaction between organisms and their environment.

Environment is : All the living and non-living things that affect an organism Biotic: living/once living Abiotic: non-living Habitat : an environment that provides all the things a specific organism needs to live and reproduce.

Levels of organization in an environment 1.Organism- A single individual of a species. (can mate and produce fertile offspring) 2. Population- Many individuals of the same species living in an area. 3. Community- Different groups of populations living together in an area. (*ALL LIVING*) 4. Ecosystem- community plus the abiotic factors.

Our school organized as an ecosystem: 1.Organism- 1 student 7th grade. 2.Population- all 7th grade students in Penndale. 3.Community- all students, teachers, custodians, pets, plants,etc. 4.Ecosystem- all people, pets, plants in Penndale plus building, rooms, etc.

Changes in population size Birth rate: the number of births per 1000 Death rate: number of deaths per 1000 Immigration: moving into a population Emigration: moving out of a population Population Density: # of individuals in an area

Notes: p. 15, 16 Interactions with the environment! Limiting Factors- any factor such as food, living space, and natural disasters, that keep a population from growing indefinitely. Any single resource can be a limiting factor. Carrying Capacity- the largest population that a given area can support over a long period of time. This number may change a little each year, but limiting factors will keep the number fairly steady. Example: The number of bears that can be supported in a forest.

Niche Niche: An organism’s way of life includes: habitat, predators, food, etc. Its “jobs” or particular role in an ecosystem. Includes abiotic factors. *NO 2 SPECIES OCCUPY THE SAME EXACT NICHE*

Interactions in an ecosystem Competition- The struggle among organisms to obtain the proper amount of food, water and living space. Competition can occur between members of different populations. Predators and Prey- When one organism hunts and eats another. The organism that is eaten is the prey. The organism that eats the prey is the predator. Predators and prey each have adaptations to help them find and catch food or to avoid danger. Examples: quick speed of the cheetah, confusion of the zebra stripes.

Interactions among Organisms!(cont.) C. Symbiosis-a close, long-term association between two or more different species. One organism lives on, in , or near another and at least one of the organisms benefits in some way!!!!!

Different types of symbiosis!! 1.Mutualism- (+,+) a symbiotic relationship where both organisms benefit. Example: bacteria/intestine. Bacteria get food and we get vitamins.

Different types of symbiosis!! (cont.) I’m going to eat your scraps you foolish SHARKS!! MUAHAHHA 2. Commensalism- (+,0) a symbiotic relationship where one organism benefits and the other is neither helped nor harmed. Example: remora/shark- A remora gets food scraps and the shark is unaffected.

Different types of symbiosis!! (cont.) Parasitism – (+,-) a symbiotic relationship where one organism benefits and the other is harmed. Parasite: the organism who benefits Host: the organism who is harmed Example: Tomato hornworm/wasp – The wasp lays its eggs on the back of the hornworm and when the young hatch out, they eat the worm alive!!!

Energy Flow in an ecosystem 1.Producer (autotroph)-organisms that use sunlight directly to make food: photosynthesis (or chemosynthesis) examples: plants, algae, phytoplankton and some bacteria. 2.Consumer (heterotroph)- organisms that eat producers or other living things to get energy.

EATING!!!!!!! Types of Consumers Herbivore- eats plants ex: deer Carnivore- eats flesh ex: wolf Omnivore- eats plants and animals ex: raccoon, human Scavenger- eats dead organisms ex: vulture (detritivore)

Decomposer Special consumers . Get their energy by breaking down dead organisms. Produce water and carbon dioxide in the process. Returns nutrients to soil ex: bacteria, fungi.

Energy Flow through an Ecosystem Food Chain: Representation of how energy flows in one pathway through an ecosystem. (who eats whom) Food Web: Many food chains that are interconnected.

Energy Pyramid.. (Also called a Trophic Pyramid) Diagram that represents the quantity of energy that flows through an ecosystem. Only about 10% of the energy is available for the next level.