teacher's slides
Post on 06-Apr-2018
302 Views
Preview:
TRANSCRIPT
-
8/3/2019 Teacher's Slides
1/26
Energy Transfer in Ecosystem
1
-
8/3/2019 Teacher's Slides
2/26
Menu for todayMenu for today
You will learn about Producers and consumers how energy is transferred from one
organism to another. constructing and interpreting food
chains/ food webs food pyramid- energy
about the consequences of adding orremoving an organism from anenvironment
2
-
8/3/2019 Teacher's Slides
3/26
14.1 Energy in Ecosystem
14.1 Energy in Ecosystem
In order to live, plants and animals in anecosystem need energy.
How can energy be transferred within theecosystem?
Energy flows within an ecosystem whenorganisms feed on each other or in terms offood
The energy transferred decreases as it passesfrom one organism to another.
In order to live, plants and animals in anecosystem need energy.
How can energy be transferred within theecosystem?
Energy flows within an ecosystem whenorganisms feed on each other or in terms offood
The energy transferred decreases as it passesfrom one organism to another.
SUNSUNGREEN
PLANTS
GREEN
PLANTS
PLANT-
EATERS
PLANT-
EATERS
MEAT-EATERSMEAT-EATERSphotosynthesisphotosynthesis foodfood foodfood
3
-
8/3/2019 Teacher's Slides
4/26
Definition:Definition:
A food chain consistsofa seriesoforganismsthrough whichenergyistransferred.
Eachorganism (plantor animal) iscalled a
link.
What is aFood Chain???
What is aFood Chain???
Food ChainFood Chain
4
-
8/3/2019 Teacher's Slides
5/26
Green leaf Caterpillar Bird
Each arrow ( )means iseaten by. A threelink foodchainorthreetropic
levels.
5
-
8/3/2019 Teacher's Slides
6/26
Food ChainFood Chain
seaweed water snail fish bird
An example of a food chain in a local
rocky shore ecosystem:
An example of a food chain in a local
rocky shore ecosystem:
6
Link Organism in Food Chain Example
Producer
Green plants that produce their own food; mostfood chains start with green plants; theyprovide food and energy for animals in the foodchain.
Seaweed,water snail,fish, bird
Consumer
Animals cannot make food, so they consumeother plants or animals.
primary: animals that eat plants only Water snail
secondary: animals that eat other animals Fish, bird
-
8/3/2019 Teacher's Slides
7/26
Food ChainFood Chain
Energy transfer in a food chain.
In a food chain, energy is passed from one organism toanother.
Energy transfer in a food chain.
In a food chain, energy is passed from one organism toanother.
producerproducer
primary consumerprimary consumer
secondary
consumer
secondary
consumer
tertiaryconsumer
tertiaryconsumer
7
-
8/3/2019 Teacher's Slides
8/26
Food WebsFood Webs
An ecosystem is made up of many interconnected foodchains.An ecosystem is made up of many interconnected foodchains.
This is because manyanimals eat more thanone type of food. The
network of food chainsis called a food web.
As there are many food chains in thefood web, the energy flow through theecosystem takes many different paths.
As there are many food chains in thefood web, the energy flow through theecosystem takes many different paths.
8
-
8/3/2019 Teacher's Slides
9/26
Green plants
Earthworms Grasshoppers Field mice
Toads Lizards
Snakes
9
-
8/3/2019 Teacher's Slides
10/26
(a) Fromthefood web shown above,constructa foodchain with
(ii) four links.
green plant earthworm toad snakegreen plant grasshopper toad snake
green plant grasshopper lizard snake10
-
8/3/2019 Teacher's Slides
11/26
(b) Namethe producer.
green plants
(c) Nametheherbivores.
earthworm, grasshopper, field mice
11
-
8/3/2019 Teacher's Slides
12/26
14.2 Energy Loss in Food Chains14.2 Energy Loss in Food Chains
As energy passes along a food chain, the amount ofenergy transferred gradually decreases.
Energy is lost to the environment at each link in thefood chain.
As energy passes along a food chain, the amount ofenergy transferred gradually decreases.
Energy is lost to the environment at each link in thefood chain. movement and breathing
(energy released)
movement and breathing
(energy released)
waste
(energy dissipated)
waste
(energy dissipated)
body
(energy stored)
body
(energy stored)
Energyis lost :
throughrespiration
asheatInurine andfaeces.
tocarryoutactivities.
12
-
8/3/2019 Teacher's Slides
13/26
Because the amount of energy transferreddecreases along the food chain, there arerarelymore than four links in a food chain. Therewould not beenough energy to support the fifthpopulation of consumers.
13
-
8/3/2019 Teacher's Slides
14/26
Leaves caterpillars bird
The Pyramid of NumbersThe Pyramid of Numbers
What is aPyramid of Numbers???
What is aPyramid of Numbers???If the pyramid isrepresented in
numbers we call it a
Pyramid of Numbers
14
-
8/3/2019 Teacher's Slides
15/26
15
-
8/3/2019 Teacher's Slides
16/26
16
-
8/3/2019 Teacher's Slides
17/26
Whentheconsumers arein largenumbers,the pyramidisinverted as
shown below.
17
-
8/3/2019 Teacher's Slides
18/26
Pyramid of Biomass
Biomassisthemassof livingmatter.
A Pyramid of Biomass showsthemassof livingmatter ateachtrophic level.
Thearea ofeach box representstheamountofbiomass ofeach linkinthefoodchain.
18
-
8/3/2019 Teacher's Slides
19/26
19
-
8/3/2019 Teacher's Slides
20/26
A frogfeedon 200 caterpillars. The 200caterpillarsfeedon 15 000 leaves. Draw
a pyramidofbiomasstorepresentthefoodchain,ifa froghas a massof250 g, a caterpillar 30 g and a leaf
10 g.
20
-
8/3/2019 Teacher's Slides
21/26
Leaves caterpillars frogs
1 frog = 250 g 200 caterpillars = 200 x 30 = 6 000g
15 000 leaves = 15 000 x 10 = 150 000g
150 000 g
6 000 g
250 g
leaves
caterpillars
frog
21
-
8/3/2019 Teacher's Slides
22/26
14.3 The Balance of Nature14.3 The Balance of Nature
The numbers of animals and plants in a food web are finelybalanced so that each animal in the food web has enoughfood to eat.
The balance between the number of plants and animals inan ecosystem is called the balance of nature.
Some ways that the links in food webs can be changed:
Diseases can kill one kind of plant or animal
Animals and plants are introduced into the habitat
Human activities often break the links in food webs
The numbers of animals and plants in a food web are finelybalanced so that each animal in the food web has enoughfood to eat.
The balance between the number of plants and animals inan ecosystem is called the balance of nature.
Some ways that the links in food webs can be changed:
Diseases can kill one kind of plant or animal
Animals and plants are introduced into the habitat
Human activities often break the links in food webs
22
-
8/3/2019 Teacher's Slides
23/26
Green plants
Earthworms Grasshoppers Field mice
Toads Lizards
Snakes
23
-
8/3/2019 Teacher's Slides
24/26
EXAMPLE
Refertothefood web above.
Insecticides are sprayed to killearthworms, grasshoppers and field
mice feeding on the plant. Explain howthis might result in the death of thesnakes.
24
-
8/3/2019 Teacher's Slides
25/26
ANSWER
Snakesfeedontoads, lizards and fieldmice.
Thedeathoftheearthworms,grasshoppers andfieldmicereducesthenumberoftoads and lizards astheyhavelessfoodtoeat.
Intheend,thesnakes will die becauseofinsufficientfood.
25
-
8/3/2019 Teacher's Slides
26/26
What have you learnt?
26
What is the difference between a food chain
and a food web?
What is the difference between a primary
and secondary consumer?
In what ways are energy lost in a food
chain?
Why is there rarely food chains with more
than 4 links?
top related