CHAPTER 3

Feeding Relationships

LEVELS OF ORGANIZATION REVIEW

SPECIES POPULATIONS COMMUNITIES ECOSYSTEMS BIOME BIOSPHERE

REVIEW TERMS

ECOLOGY: scientific study of interactions among organisms, between organisms, in their environment

BIOSPHERE: the world (combining ALL parts of the world)

COMPARE and CONTRAST

PRODUCERS vs. CONSUMERSP = use sunlight/chemicals to make

own food/energyC = use other organisms for

food/energy AUTOTROPHS vs. HETEROTROPHS

A = AKA producerH = AKA consumer

TYPES OF PRODUCERS

PHOTOSYNTHESIS—use sunlight to make carbohydrates (sugars)

CHEMOSYNTHESIS—use chemicals to make carbohydrates (sugars)

TYPES OF CONSUMERS

HERBIVORES: energy from only plants• i.e. cows and deer

CARNIVORES: energy from only animals• i.e. tigers and dogs

OMNIVORES: energy from both plants and animals

• i.e. humans and bears DETRITIVORES: energy from remains of

plants and animals • i.e. mites and crabs

TROPHIC LEVELS Energy levels in a food chain or food web

Producers = always first trophic levelConsumers = make up the second, third,etc. trophic

levelsDecomposers = the last trophic level

Grass → Caterpillar → Hawk → Wolf → Mushroom

Arrows represent the flow of energy from one organism to the next

Producer Primary Consumer

Secondary Consumer

Tertiary Consumer

Decomposer

FOOD CHAIN

Energy transfer from one organism to another in a series of steps

EXAMPLE:

Grass → Caterpillar → Hawk → Wolf → Mushroom Producer Primary

ConsumerSecondary Consumer

Tertiary Consumer

Decomposer

FOOD WEBS

More complex than food chain

Shows relationships among many different animals in an area

Where are the trophic levels in this figure?

ENERGY PYRAMIDS

ENERGY PYRAMID: Shows the relative amount of energy available in

each trophic level BIOMASS PYRAMID:

Total amount of living tissue for each trophic levelRepresents the amount of food available in each

trophic level PYRAMID OF NUMBERS:

Number of organisms in each trophic level

•Organisms use about 10% of energy from each trophic level

•The rest is lost as heat

Biomass

Numbers

Energy

RULE OF 10

Only 10% of energy is transferred from one trophic level to the next.

Example:It takes 100 kgs of plant materials

(producers) to support 10 kgs of herbivores

It takes 10 kgs of herbivores to support 1 kg of 1st level predator

Symbiosis – “living together”

Symbiosis Type

Species A Species B

Commensalism + (benefit) 0 (neutral)

Mutualism + (benefit) + (benefit)

Parasitism + (benefit) - (harmed)