Unit 2 – Lecture 2

EcologyEcology -

the relationship between an org and its environment

Includes relationships betweenbiotic and other biotic factorsbiotic and abiotic factors

Important ConceptsHabitat –

where an org lives [tree, lake,

burrow…etc] Niche –

what an org doesmaking dams, eat-

ing certain orgs, etc.

EVERYTHINGit does, basically.

Biotic Biotic RelationshipsSymbiosis – a relationship between 2 orgs

three types that we will cover:mutualism – benefit-benefit

often referred to as simply symbiosis, but you must use the more specific term

commensalism – benefit-unaffectedparasitism – benefit-harm

Discuss

Come up with 2 examples of each of the symbiotic relationships:

mutualism [benefit-benefit]commensalism [unaffected-benefit]

parasitism [harmed-benefit]

BioticBiotic cont’dOther – Non Symbiotic – Relationships

Predator-Prey – one org feeds off of the other

Competition – organisms compete for the same

resources

Food Chains & Food WebsDo Not list humans, decomposers, or

scavengers.detritovore – feeds off of detritus [dead or

decaying organic matter] – decomposers/scavengers

Food Chain – a linear representation of feeding chains are linear – a single lineex:

Food Chains & Webs – cont’d

Food Web – a branched & often interconnected representation of feeding webs have many branches and

interconnectionsex:

Descriptive Org TermsAutotroph – an organism which makes its

own food“auto-” – self “troph” – nutrients / food / feederaka producerexamples?

Descriptive Org Terms – cont’dHeterotroph – cannot make its own food,

feeds off of other organisms“hetero” – different aka consumer“vore” terms – carnivore, omnivore,

herbivore, detritovore/decomposer

Discuss

What do each of these “vore” terms mean?

carnivoreomnivoreherbivore

detritovore

Descriptive Org Terms – cont’ddecomposer – obtains nutrients by

breaking down decaying organic matterorganic – any substance containing the

element Carbon

Sequence Terms for ConsumersUsed in food chains or food pyramids for

CONSUMERS, NOT in food webs. You may use either of the given terms.

Primary aka First Order consumerseats the producerherbivore or omnivore

Secondary aka Second Order consumerseats the primary/1st order consumeromnivore or carnivore

Sequence Terms – cont’dTertiary aka Third Order consumer

eats secondary / 2nd order consumercarnivore or omnivore

Quaternary aka Fourth Order consumereats tertiary / 3rd order consumercarnivore or omnivore

etc…

Terms in Chains & PyramidsTop Predator –

an animal with has no natural enemieswill always be final step in food chain /

pyramidNOT all pyramids & chains have a top

predator

HUMANS ARE NOT TOP PREDATORS…

Discuss / Complete

Fill in #4 on your sheet using the terms you just learned in #s 1-3.

[sequence terms, vore terms, and the rest]

Check Your Work!

Producer

Autotroph

Heterotroph

1st Order Consumer

Primary Consumer

Omnivore

Heterotroph

2nd Order Consumer

Secondary Consumer

Carnivore

Heterotroph

3rd Order Consumer

Tertiary Consumer

Carnivore

Top Predator

Energy/Food PyramidsEnergy Pyramid – a pyramid-shaped

representation of a food chainshows the transfer of energy btw

organisms

only 10% of the energy taken in is passed on to the next trophic level

90% of energy taken in is lost [used for fuel for the body’s actions and for body’s reactions]

Energy/Food PyramidsEnergy Pyramid – a pyramid-shaped

representation of a food chaintrophic level – a nutrient/food level

[“troph…”

each step in a food chain, web, or energy pyramid is a new trophic level

a pyramid will have as many levels as the food chain it represents

Energy/Food Pyramidsthe terms used to describe orgs on the food

chain are also used for each trophic level here.

as available energy decreases, the number of organisms [circle one: also decreases / increases].

Homework

Complete the Food Chains, Food Webs & Food Pyramids worksheet

found on pages 6-7 in your packet.