SYMBIOSIS & FOOD CHAINS

Unit 5 - Ecology

Introduction

Relationships exist in order for one or both organisms to get food (energy).

Sunlight is the main source of energy on Earth.

Section 1

Food Chains/Food Webs

Feeding Style

Producers Produce their

own food; get energy from sunlight

Consumers acquire energy

from other organisms.

Autotrophs Heterotrophs

Types of Consumers

Herbivores eat plants

(cows) Carnivores

eat animals (snakes)

Omnivores eat plants &

animals (humans)

Detritivores eat plant/animal

remains & other dead matter. (vultures, earthworms, maggots…)

Decomposer feed on

decaying/dead matter; return organic compunds back to soil. (fungus & bacteria)

Detritivore

Omnivore

Carnivore Herbivore Decomposer

Food Chains/Webs

Energy (food) is passed from organism to organism through food chains and food webs.

Food Chain a series of steps in

which organism transfer energy by eating & being eaten.

Food Web links all the food

chains in a ecosystem together.

Trophic Levels

Trophic Level – each step in a food chain or food web. 1st trophic level is

always a producer (autotroph)Plants, algae,

plankton 2nd trophic levels

and up are consumers. (heterotroph)

Trophic Levels

A primary consumer is the first consumer of a food chain (consumes the producer) second trophic level

(the producer is always the first)

A secondary consumer is the second consumer of a food chain (consumes the primary consumer) third trophic level.

A tertiary consumer is the third consumer of a food chain (consumes the secondary consumer) Fourth trophic level.

Section 2

Relationships

Relationships

I.) Symbiosis 2 or more

species live together in a close, long-term association.

II.) Predation one organism

feeds on another; one benefits and one is hurt (may or may not be kill)

Symbiosis

Mutualism: both organisms benefit Ex. Shark &

remora/ herd animals & birds/goby fish & shrimp+, +

Symbiosis

Commensalism: one organism benefits and the other is neither harmed nor helped. Ex. Sea

anemone & tropical fish+,O

Symbiosis

Parasitism: one organism feeds on & usually lives on or in another organism. Ex. Ticks,

mosquitoes, tapeworm, heartworm, +, -

Predation

II.) Predation: one organism feeds on another; one benefits and one is hurt (may or may not be kill) Ex. Snakes –

predator / mice prey