food chains, food webs, and the transfer of...
TRANSCRIPT
Ecology is the scientific study of interactions between
different organisms and between organisms
and their environment or surroundings
What is Ecology?
Every organism has a habitat and a niche.
A habitat is all the aspects of the area in which an organism lives
biotic (living) factors such as trees, animals
abiotic (non-living) factors such as water, soil, sun, wind
Where are you from?
A niche includes all of the physical, chemical, and biological
factors that a species needs to survive, stay healthy, and reproduce.
What do you do? (behavior)
What do you eat / how do you eat?
Are you the top predator?
You can think of a habitat as where a species lives
and a niche as how it lives within its habitat. Niche Video
How are organisms classified in an
ecosystem?
What they eat or how they get their
food (producers, consumers, and
decomposers).
The Producers (Autotrophs)
•A group of organisms that can use the energy in sunlight to convert water and carbon dioxide into Glucose (food) through photosynthesis. They make /produce their own food.
•Sunlight is the main energy source for life on earth
•The chemical formula for photosynthesis is:
The Producers (Autotrophs)
• Autotrophs are also called Producers because they produce all of the food that heterotrophs use
• Without autotrophs, there would be no life on this planet
• Ex. Plants and Algae
The Consumers (Heterotrophs)
Organisms that do not make their own food can be referred to as consumers, they consume other organisms for their energy and food supply. Ex. Rabbits, Deer, Mushrooms
Consumers (Heterotrophs)
Scavengers/Detritivores – feed on the tissue of dead organisms (both plants and animals)
• Ex. – Vultures, Crows, and Shrimp
Decomposers
Decomposers – absorb any dead material and break it down into simple nutrients or fertilizers
• Ex. – Bacteria and Mushrooms
Feeding Interactions between organism –
Energy Flow and the Food Chain
Energy flows through an ecosystem in one direction
from the sun or inorganic compounds to autotrophs
(producers) and then to heterotrophs (consumers)
**The sun is the initial source of energy for food chains.
Food Chain—series of steps in which organisms transfer energy by eating and being eaten. Start with producer and end with top consumer or carnivore
FOOD CHAINS
grass
grass- hopper
frog
snake
eagle Keep in mind that the arrow tip
always points towards the “eater”. The direction of how
energy is transferred. .
food
eater
Food Chains
• Question: Which direction does the arrow points ?
• Answer: It points to the direction of the energy transfer, NOT “what ate what”
• Question: What is the primary source of energy for life on earth?
• Answer: The Sun
they must eat or “________” other organisms.
FOOD CHAINS
grass
grass- hopper
frog
snake
eagle
They use the energy in _______ to make their own food
They form the _____ of almost all food chains.
Since they _______ make their own food,
sunlight
cannot
consume
basis
through a process called _____________. photosynthesis
Broken down into
producers and consumers.
It’s at the ___ of its food chain.
FOOD CHAINS
primary consumer
tertiary consumer
quaternary consumer
secondary consumer
grass
grass- hopper
frog
snake
eagle
The ___ consumer in a food chain. It eats _________.
The ___ consumer in a food chain. It eats ________________.
The ___ consumer in a food chain. It eats __________________.
The ___ consumer in a food chain. It eats ________________.
1st
2nd
3rd
4th
producers
primary consumers
secondary consumers
tertiary consumers
any organism that is __________ by any other. not hunted top There are different levels
of consumers…..
Top carnivore:
is the ___________ and _____________ of dead organisms.
FOOD CHAINS
grass
grass- hopper
frog
snake
eagle
All organisms eventually die and
decompose.
are substances needed for an organism’s ______ and _____.
detritus
decomposers
nutrients
Nutrients:
Detritus:
are organisms that ___ _______ and break it down into ________.
Decomposers:
waste matter
rotting remains
eat
nutrients
detritus
growth repair The cycle restarts.
HUMANS AND FOOD CHAINS Have you ever eaten one of these?
onion
lettuce
tomato
What is it made of?
wheat
cheese
beef
What food chains did you
participate in when you ate this?
FOOD WEBS No ecosystem is only
made up of only one
food chain. Most
organisms eat more
than JUST one
organism. Members of
___________________
___________________
___________________
____. When you connect all
the food chains of
different organisms
from one ecosystem
together, you form
_______________.
Create a Food Web
• Form groups of 3, create a basic food web for each of the following habitats.
– Freshwater wetland
– Forest
What are Trophic Levels?
• The Energy movement from one organisms to another when it is eaten
• Each step in this transfer of energy is known as a trophic level
3rd trophic level
4th trophic level
5th trophic level
1st trophic level
TROPHIC LEVELS
grass
grass- hopper
frog
snake
eagle
2nd trophic level
phytoplankton
zooplankton
small fish
larger fish
shark
It is the position an organism occupies in a food chain. Each
link in the chain represents one tropic level. The first trophic
level starts with the producers.
This 10 % is used to build
biomass as well as to provide
energy for bodily functions
TROPHIC LEVELS
grass
grass- hopper
frog
snake
eagle
As organisms eat one another,
energy is transferred up the food
chain.
This means that 90 % of the
energy is lost,
1000 kcal
100 kcal
10 kcal
1 kcal
0.1 kcal
- 900 kcal
- 90 kcal
- 9 kcal
- 0.9 kcal
energy mostly in the form of
detritus and as heat used in
metabolic processes.
______________________—
only about 10% of the available
energy within a trophic level is
transferred to the next higher
trophic level