IB Biology

Chris McDermut

4.1.1-4.1.5 Communities and Ecosystems

• •4.1.1 Define ecology, ecosystem, population, community, species, habitat (1092-1094)– Ecology: The study of relationships between organisms and their environment– Ecosystem: A community and its abiotic environment– Population: A group of organisms of the same species who live in the same area at the same time– Community: A group of populations living and interacting with each other in an area– Species: A group of organisms which can interbreed and produce fertile offspring– Habitat: The environment in which a species normally lives of the location of a living organism

•4.1.2 Explain how the biosphere consists of interdependent and interrelated ecosystems (1092-1094)

-The biosphere consists of interdependent and interrelated ecosystems: rainforests, rivers, oceans, creeks, deserts, etc.

•4.1.3 Define autotrophs (producers), heterotrophs (consumers), detrivore, and saprotrophs (decomposers) (176-177, 1198-1199)

-Autotroph:An organism that makes its own food

-Heterotroph: An organism that obtains its food from another organism

-Detrivore: and organism that feeds on dead organic matter by ingesting it

-Saprotroph: an organism that feeds on dead organic matter by secreting digestive enzymes into it and feeds on the products

•4.1.4 Describe what is meant by a food chain, give three examples (1181)

-a food chain is the interrelation of individuals to each other

-ex1: phytoplankton, zooplankton, minnow, needle fish, osprey

-ex2: grass, mouse, cobra, mongoose

-ex3: grass, rabbit, fox, bear

•4.1.5 Describe what is meant by a foodweb (1182)

-A diagram that shows all the feeding relationships in a community

4.1.1-4.1.5 Communities and Ecosystems Visuals

4.1.6-4.1.12 Communities and Ecosystems

•4.1.6 Define trophic level (1181)

-trophic level: position in the food chain

•4.1.7 Define the tropihc level of organisms in a food chain and a food web (1181)

-Producer, primary consumer, secondary consumer, tertiary consumer, quarternary consumer

•4.1.8 Construct a food web with at least ten organisms (1182)

-see images on next slide

•4.1.9 State that light is the initial energy source for all most all living things (1199)

-light provides the energy source for autotrophs (producers), which provides the energy for all following consumers

•4.1.10 Explain the energy flow in a food chain (1181, 1199)

-light captured by plants in converted into chemical energy

-energy in plant tissues is passed to the next trophic level for cell respiration

-organic matter containing stored energy can be eaten by a second consumer

• 4.1.11 State that when energy transformations takes place, including those in living organisms, the process is never 100% efficient, usually 10-20% (1206-1207)

-The energy transformation process is never 100% efficient

•4.1.12 Explain what is meant by the pyramid of energy and the reasons for its shape (1206-1207)

-a pyramid of energy shows the flow of energy from one trophic level to the next in a community. The units of a pyramid of energy are energy per unit and per unit time.

-the pyramid becomes smaller as it gets taller because not all energy is being transferred

-some organisms die before an organism in the next level eats them

-some parts of organisms such as bones or hair are not eaten

-some parts of the organism are indegestible and pass out as feces

-much energy is absorbed by an organism in cell respiration. The energy is then used in energy transformations within the body, with also lose energy because they are not 100% efficient.

4.1.6-4.1.12 Communities and Ecosystems Visuals

4.1.13-4.1.15 Communities and Ecosystems

•4.1.12 Explain that energy can enter and leave ad ecosystem, but nutrients must be recycled (1208-1214)

-nutrients are recycled by saprotrophs and detrivores

•4.1.14 Draw the carbon cycle to show the processes involved (1211)

-see images on next slide

•4.1.15 Explain the role of saprotrophic bacteria and fungi in recycling nutrients (1208-1214)

-their enzymes break up complex compounds and free nutrients

4.1.13-4.1.15 Communities and Ecosystems Visuals

Vocabulary• -ecology• -ecosytem-interdependent and interrelated• -population• -community• -biosphere• -species• -habitat• -autotroph• -heterotroph• -detrivore• Saprotroph• -food chain• -trophic level• -pyramid of energy• -carbon cycle