2.1 and 2.2

Organisms and Their Relationships

Section 2.1

Ecology• Greek "oikos" = house• study of the interactions among living things, and between living things and their environment

Research Methods

• modelingcomputer and mathematical

(manipulate and control hypothetical situations)

makes predictions based on current data

· observationsurveys (direct and indirect)radio telemetry (tracking organisms)gather data about population size

· experimentationlab work - controlled setting and variable,

but does not reflect organisms in the wildfield work - performed in the wild, more

accurate picture of interactions but includes many variables

Biosphere• "ball of life"• portion of Earth that supports life• includes atmosphere, land, and ocean depths

1 Which of the following statements is FALSE?

AScientists study ecology using experiments, observations, and computer models.

BThe biosphere includes the atmosphere and land, but NOT water environments.

C

Ecology is the study of interactions between organism, and organisms and their environment.

DThe biosphere is the portion of earth where life exists.

Biotic vs. Abiotic• biotic - living things (plants, animals, fungi, bacteria)

biodiversity - a variety of living things• abiotic - nonliving things (nutrients, temperature, rainfall, wind, sunlight, soil)

determines which living things can survive in a particular environment

determines amount of biodiversity

2.1 and 2.2

Work together to list as many biotic and abiotic factors as you can.

What are the biotic and abiotic factors in this picture?

Levels of Organization• organism population community ecosystem biome• organism - simplest level (1 individual)• population - all the members of a species that live in one place at one time

competition for resourcesavailability of resources determines how big a population

can be• community - different populations that live together in a given area at the same time

forest: rabbits, bears, insects, ferns, foxes, etc.• ecosystem - community and all the abiotic factors that affect it

ocean: fish, plankton, algae, sun's energy, salinity, sediment, sharks• biome - large group of ecosystems that share the same climate and have similar types of communities

*includes abiotic factors

2 Which level of organization is the first to include abiotic factors?

A population

B ecosystem

C community

D biome

2.1 and 2.2

Ecosystem Interactions• habitat - area where an organism lives

habitats can change or be destroyed

changes in habitat disrupt species equilibrium• niche - role/job of an organism in its habitat

how it meets its needs for food, shelter, reproduction and survival

Community Interactions• competition occurs when organisms need the same resource at the same time

ex. water, space, mates, light• survival of the fittest• if resource is plentiful, competition may not exist• predation - consuming another organism for food

predator - one who eatprey - one who gets eaten

predator

prey

3 ___ is where an organism lives, and ___ refers to an oganism's job/role.

A niche, habitat

B habitat, niche

C niche, predation

D habitat, predation

Symbiotic Relationships• symbiosis - close relationships with other species

increases chance of survival• mutualism - both species benefit• commensalism - one species benefits and the other is neither helped nor harmed• parasitism - one species benefits and the other is harmed

parasitism commensalism

mutualism

Flow of Energy in an Ecosystem

Section 2.2

Producers• can make their own food

aka autotrophsfoundation of all ecosystems

• sun - main energy sources for life on Earth

photosynthesis turns CO2 into carbohydrates

ex. algae, plants, cyanobacteria• inorganic substances

chemosynthesis - form carbohydrates using chemicals as the energy source

ex. deep sea vents, hydrothermal pools, salt marshes

2.1 and 2.2

Consumers• rely on other organisms for energy (food)

aka heterotrophs• examples

carnivore - meat eatersherbivore - plant eatersomnivore - plants and animalsdetritivore - plant/animal remainsdecomposers - breakdown organic matter (type

of detritivore)• specialists - picky eaters (1 or few organisms)

subject to ecological changes• generalists - eat anything (varying diet)

1 MATA: Autotrophs

A are also called producers

B can make their own food

Care the foundation of all ecosystems

D need chemicals

2 MATA: Consumers

A need to eat to get their nutrients

B include plants

C are also called heterotrophs

Dinclude herbivores, carnivores, and detritivores

Food Chains• energy flows through an ecosystem

sun/inorganic substance autotrophs heterotrophs• food chain - sequence of energy flow based on feeding relationships

producers herbivore carnivorearrow always points in direction of energy transfertriggerfish shark NOTshark triggerfish

2.1 and 2.2

Food Webs• link all the food chains in an ecosystem together• more complex

Let's practice...can you identify the producers and consumers.

What would happen to this food web if the arctic hare population decreased? Trophic Levels

• each step in a food chain or web• energy flows up the food chain/web from lowest trophic level to highest

3 consumers - carnivores/omnivores2 consumers - carnivores/omnivores1 consumers - herbivores/omnivoresproducers (supplies energy for food chain/web)

• each trophic level contains less energy than the level below it

Biomass Pyramid• biomass - total mass of living matter at each trophic level• biomass pyramid - mass of living tissue in each trophic level

Energy Pyramid• only 10% of available energy in 1 trophic level is passed on to the next trophic level• rest lost as heat

2.1 and 2.2

Pyramid of Numbers• shows # of organisms at each trophic level

3 Only 10% of available energy is passed to the next trophic level, the rest is lost as heat.

True

False

4 Producers are always at the bottom of a pyramid, represent the greatest biomass and energy in a food chain, and are the most numerous.

True

False