Transcript Ecosystems,FoodWebs,FoodChains(Review)

Unit 3 Ecosystems
Chapter 6
Part 1
The Web Of Life p. 92
&
Food Relationships p. 93
Questions #3-9 in the book
Define Ecosystem
Ecosystem = the network of relationships
(interactions) among plants, animals and the nonliving parts in an environment.
Differentiate the terms producers, consumer,
decomposers. P. 93
Other examples:
Grasses
Trees shrubs
Water lilies
Flowers
Vegetables
Fruits
Producer = a plant which can synthesize carbohydrates
using carbon dioxide and the sun’s energy.
Actually “produce” their own food and food for the rest of
the ecosystem
Differentiate the terms producers, consumer,
decomposers. P. 93
Consumers = All those organisms that have
to eat (consume) plants or animals to obtain
their food.
Types of consumers
Primary Consumers: Animals that eat
producers. Also called 1st. order consumers.
(Ex. Rabbit, squirrels, grouse, insects)
Secondary Consumers: Animals that eat
primary consumers. Also called 2nd. order
consumers. (fox, owl, mink )
Tertiary Consumers: Animals that eat
secondary consumers. Also called 3rd. order
consumers. (Wolf, coyote, hawk)
Differentiate the terms producers, consumer,
decomposers. P. 94
Examples:
Worms
Bacteria
Fungi
Protozoa
• Decomposers = Simple organisms that obtain
their food from dead/decaying organisms and
wastes.
Consumers, producers & decomposers….
Similarities
All three are terms
referring to the way
organisms obtain food &
energy
Differences
The way they obtain food
Producers make it,
Consumers eat it,
Decomposer feed on
wastes & dead material.
Differentiate the terms food chain & food
web. P. 94
Food chain =
linear sequence
representing the
nutrition of
various species
from the simplest
plant to the top
carnivore.
Food web = a
series of
interconnecting
food chains in an
ecosystem.
Food Chain
vs
Food Web
Differentiate the terms food web & food chain. P. 94
Similarity
Both food chains and
food webs show the
flow of nutrients and
energy in an
ecosystem.
Difference
Food web is more
complex
Food web is composed
of several food chains
Food web is a more
realistic picture of an
ecosystem.
Identify examples of producers & consumers
See “Handout”
Producers
Primary Consumers
Secondary Consumers
Tertiary Consumers
Decomposers
Give an example
of a food chain
from fig. 6.4. P.
95
Tree
insect
→
Producer
→
Primary
consumer
insect eating
hawk
bird
→
2nd order
consumer
3rd order
consumer
Note: The arrows indicate the flow of energy & nutrients from
one level to the next
Sample Food Chain
Draw an example of a food web containing
humans. P. 94
Hawk
Mosquito
Cow
Grass
Man
Decomposer
fish
Phytoplankton
Using figure 6.5 summarize the main energy flows in an
ecosystem p. 95
Sun = source of all
ecosystem energy
Producers make food via
photosynthesis
Consumers eat plants
and other consumers to
get energy
Each time energy moves
from one organism to
another, energy leaves
the system in the form of
heat.
Decomposers return
nutrients to the soil but
energy is not recycled. It
is lost!
Summary – Energy & Food Webs
The ultimate source of energy (for most ecosystems) is the
sun
The ultimate fate of energy in ecosystems is for it to be lost
as heat.
Energy and nutrients are passed from organism to
organism through the food chain as one organism eats
another.
Decomposers remove the last energy from the remains of
organisms.
Inorganic nutrients are cycled, energy is not.
Question #14, 15 & #16 p. 98 make perfect review
questions for the test.
Energy flow…another look!!