Lesson 1: Just Another Day in the Hood
An Introduction to Symbiotic Relationships in the
Coral Reef Ecosystem
Kira Withy-Allen
Teacher/Research Assistant
University of California, Santa Barbara
Research Experience for Teachers
National Science Foundation
Background: Moorea LTER Unit
Can you outsmart a scientist?
• In the following lessons, you will be the brains
behind research done by scientists at the
University of California, Santa Barbara.
• You will decide what their hypotheses should be
and how they should set up their experiments.
• The scientists you are up against have spent
many years studying the ecology of organisms,
so be prepared for some big competition!
• Since there are no coral reefs in California, the
scientists must travel to the island of Moorea,
French Polynesia to conduct their research.
Do you have a coral reef near you?
Moorea is a tropical island
in French Polynesia. It is
near the Northwestern end
of Tahiti.
The island of MOOREA
UC Berkeley Gump Research
Station: Where scientists live
and conduct research while in
Moorea.
Scientists in Moorea are
studying a barrier reef.
This is a reef that is
parallel to the shore and
usually separated from
land by a lagoon.
UC Berkeley Gump Research Station
Moorea, French Polynesia
Tahitian hut
(“Fare”)
Dorms
Wet and Dry
Laboratories
Repair Shop
Library
Research
Boats
The scientists we will encounter in the next two
lessons have been studying different
organisms that participate in “symbiosis.”
Symbiosis: A close relationship between two organisms.
Many symbiotic organisms share a living space.
Symbiont: Usually the smaller
organism in a symbiotic relationship.
Example: Algae called zooxanthellae
that often live inside the tissue of a coral.
Host: Usually the larger
organism in a symbiotic
relationship.
Example: A coral polyp.
In this case, the Symbiont lives
inside of the tissues of the Host.
There are three main trends observed with organisms
that participate in symbiotic relationships.
• Mutualism: A relationship between two organisms
(host and symbiont) in which both benefit from the
interaction.
Host
Symbiont
• Parasitism: A relationship between two organisms in
which one organism benefits at the other organism's
expense.
Host
Symbiont
• Commensalism: A relationship between two
organisms in which the host neither benefits nor is
hurt by the relationship.
Host
Symbiont
A Symbiotic Relationship:
Coral and Zooxanthellae
For the rest of this lesson, we are going to learn
what life processes corals and zooxanthellae must
do in order to survive.
Assignment: You are expected to decide the main
reason why coral and zooxanthellae might be found
living together on the reef. On your paper, jot down
notes or draw pictures that may help you decide.
What do plants and algae need to survive?
•
•
•
Discuss what you think plants and algae in the ocean or on land need
to survive.
Do ocean and land plants need the same things? What is the same?
What is different?
Brainstorm and write down your ideas.
Ocean Algae: Zooxanthellae
Land Plant: Rainforest Tree
Optional Activity: DEBATE
Question: Are plants and algae the same thing?
Divide students in the classroom into two groups. One group
supports the notion that plants and algae are the same thing
and the other group will challenge this by mentioning any
differences between the two.
Stumped?
Scientists have spent a lot of time debating this issue.
Some Similarities:
• Both are producers that carry out a process called Photosynthesis.
• Both have chlorophyll and chloroplasts.
• Both can be found on land and in the aquatic environment.
Some Differences:
• Protists (most algae) and Monera (Blue-green algae) come from
different kingdoms than plants (Plantae) . Note: Chlorophycota is
commonly slumped with Plantae.
• Algae and plants don’t share a similar structure (i.e. roots).
Plants and algae, both on land and in water, survive using similar
basic resources. However, they take in the resources in different
ways and from different materials depending on the environment.
All plants need:
1. An Energy Source:
Sunlight or artificial light.
Plants and algae have a special green
pigment called chlorophyll that allows them
to attract and absorb sunlight rays.
Inputs: Resources organisms use to function.
All plants need:
1. An Energy Source:
Sunlight or artificial light.
2. Water is very
important for
organisms to
function correctly.
H2O
All plants need:
1. An Energy Source:
Sunlight or artificial light.
CO
2
3. Carbon
Dioxide gas is
absorbed from
the water.
2. Water is very
important for
organisms to
function correctly.
H2O
All plants need:
1. An Energy Source:
Sunlight or artificial light.
CO
2
3. Carbon
Dioxide gas is
absorbed from
the water.
4. A food source: Nutrients from soil,
decaying organisms, or the surrounding
environment.
2. Water is very
important for
organisms to
function correctly.
H2O
What happens to these resources once
they are taken up by a plant?
Assignment: Brainstorm and discuss at least 5
reasons why plants are important on Earth and use
these reasons to answer the question above.
Hint: Some questions you may want to ask yourself include: Do plants
benefit you in any way? Where do you find plants? What are they used
for? Do we NEED plants?
Why are plants and algae important?
Animals (including us) use the outputs of plants as
food and for additional resources.
INPUTS
OUTPUTS
CH O
6
12
6
Glucose, a
simple sugar
molecule that
stores energy.
CO2
Outputs: What an organism produces or releases after using the inputs.
INPUTS
OUTPUTS
CH O
6
12
6
1. Glucose, a
simple sugar
molecule that
stores energy.
CO2
H2O
O2
2. A gas called Oxygen is
released. Does that word
sound familiar?
INPUTS
OUTPUTS
CH O
6
12
6
1. Glucose, a
simple sugar
molecule that
stores energy.
CO2
H2O
O2
2. A gas called Oxygen is
released. Does that word
sound familiar?
3.
WASTE
INPUTS
OUTPUTS
CH O
6
6
1. Glucose, a
simple sugar
molecule that
stores energy.
4. Water is
usually an input
and output.
CO2
12
H2O
O2
2. A gas called Oxygen is
released. Does that word
sound familiar?
3.
WASTE
Does anyone know what this process
that plants and algae perform is called?
PHOTOSYNTHESIS! Can you say it?
Another crazy scientific word! At least that was easier to pronounce than
zooxanthellae, right? But now I forgot what photosynthesis is! Can you
define it?
Photosynthesis: A chemical process in which green plants combine carbon
dioxide and water in the presence of light energy and chlorophyll to produce
carbohydrates and oxygen.
Sunlight+ Carbon Dioxide+ Water + Nutrients
Glucose+ Oxygen+ Waste+ Water
That’s what you SAID, I’m sure of it!
Test yourself: Do you know the symbols for some of the molecules, such as
Carbon Dioxide?
This whole process of photosynthesis takes place
in a specialized organelle, which is found inside
plant and algal cells. It is called a…
CHLOROPLAST: A specialized organelle inside a plant or algal
cell where photosynthesis takes place.
Note that the chloroplast (light
green) has the chlorophyll
pigment (dark green) inside of it
to attract the sunlight so the
process of photosynthesis has
energy to begin.
Do zooxanthellae
perform photosynthesis?
• You bet!
• Scientists believe that zooxanthellae and other
phytoplankton (often microscopic plants) in the
ocean produce AT LEAST HALF of our Earth’s
OXYGEN via photosynthesis.
• Since organisms that perform photosynthesis can
make their own food, they are called producers.
Supplemental article: “Source of Half Earth's Oxygen Gets Little Credit”
http://news.nationalgeographic.com/news/2004/06/0607_040607_phytoplankton.html
What does all of this photosynthesis
stuff have to do with CORAL?
POP QUIZ
aaaggghh…
1. Are corals plants?
No! Coral is an animal.
2. Does coral perform
photosynthesis?
No! Animal cells do not
have chloroplasts.
3. What is the process that
animals perform to survive
called?
RESPIRATION
Respiration: A chemical process that releases the
energy stored in food and forms new products.
INPUTS
CH O
6
12
6
1. An energy source:
Glucose, a simple sugar
molecule that stores
energy made through
photosynthesis.
Coral
Respiration
INPUTS
CH O
6
12
6
1. An energy source:
Glucose, a simple sugar
molecule that stores
energy made through
photosynthesis.
2. Water is very
important for
organisms to
function correctly.
H2O
Respiration
INPUTS
CH O
6
12
6
1. An energy source:
Glucose, a simple sugar
molecule that stores
energy made through
photosynthesis.
O2
3. Oxygen gas is either
absorbed from the water
by tissues (coral) or gills
(fish), or taken in
through the lungs from
the air (whales).
2. Water is very
important for
organisms to
function correctly.
H2O
Do you recognize any of the
INPUTS for respiration?
You should, they are the OUTPUTS for
photosynthesis!
BOB is shocked.
What are the outputs for respiration?
INPUTS
CH O
6
12
OUTPUTS
HEAT
6
Glucose
O2
Oxygen gas
1. The energy in food (such
as glucose) is transferred
to the animal to run its
bodily processes, and is
then released as heat.
Energy does not get used
up, it just transfers from
one object to another.
Water
H2O
Respiration
INPUTS
CH O
6
12
OUTPUTS
HEAT
6
Glucose
O2
Oxygen gas
1. The energy in food (such
as glucose) is transferred
to the animal to run its
bodily processes, and is
then released as heat.
Energy does not get used
up, it just transfers from
one object to another.
Water
H2O
CO2
2. Gas: Carbon Dioxide
gas is released into the
water.
Respiration
INPUTS
CH O
6
12
OUTPUTS
HEAT
6
Glucose
O2
Oxygen gas
1. The energy in food (such
as glucose) is transferred
to the animal to run its
bodily processes, and is
then released as heat.
Energy does not get used
up, it just transfers from
one object to another.
Water
H2O
CO2
2. Gas: Carbon Dioxide
gas is released into the
water.
3. WASTE/NUTRIENTS
Respiration
INPUTS
CH O
6
12
OUTPUTS
HEAT
6
Glucose
O2
Oxygen gas
1. The energy in food (such
as glucose) is transferred
to the animal to run its
bodily processes, and is
then released as heat.
Energy does not get used
up, it just transfers from
one object to another.
4. Water is usually
an input and output.
H2O
CO2
2. Gas: Carbon Dioxide
gas is released into the
water.
3. WASTE/NUTRIENTS
Consumer vs. Producer
Organisms that undergo respiration are often
called Consumers because they cannot perform
photosynthesis to make their own food, so they
must consume it from something else.
Exception: Producers
Do you remember what producers are?
Producers make their own food by performing
photosynthesis (i.e. plants), but in order to gain
energy to use for their processes, they must also
do respiration and use small amounts of their
own food (glucose) energy that is stored.
Do you recognize any of the
OUTPUTS from respiration?
You should, some are the INPUTS for
photosynthesis!
Congratulations, BOB is shocked again!
Remember this Assignment?
A Symbiotic Relationship:
Coral and Zooxanthellae
Assignment: You are expected to decide the main reason why
coral and zooxanthellae might be found living together on the
reef. On your paper, jot down notes or draw pictures that may
help you decide.
Take a few minutes now to finish processing your
thoughts. Have you thought of any ways that
zooxanthellae and coral could help each other out?
REVIEW: PHOTOSYNTHESIS
INPUTS
OUTPUTS
CH O
6
12
6
or
CO2
O2
H2O
WASTE
REVIEW: RESPIRATION
H2O
INPUTS
CH O
6
12
HEAT
6
O2
OUTPUTS
or
CO2
WASTE/NUTRIENTS
PHOTOSYNTHESIS and RESPIRATION are opposite processes.
The INPUTS for photosynthesis are the OUTPUTS from respiration!
PHOTOSYNTHESIS INPUTS
Sunlight+ Carbon Dioxide+ Water + Nutrients*
PHOTOSYNTHESIS OUTPUTS
Glucose+ Oxygen+ Waste (nutrients)*+ Water
The OUTPUTS from photosynthesis are the INPUTS for respiration!
RESPIRATION INPUTS
Glucose+ Oxygen+ Nutrients+ Water
*Note: Matter is recycled!
Nutrients such as Nitrogen
can come out as waste from
a consumer is “fixed” by
bacteria so that it can be
taken up again as fertilizer
by the producer.
RESPIRATION OUTPUTS
Heat+ Carbon Dioxide+ Water + Nutrients* (waste)
Okay, we need to
stop shocking BOB
before his hands
become permanently
stuck to his face.
What does this mean for organisms that live symbiotically
and can perform both photosynthesis (zooxanthellae) and
respiration (zooxanthellae and coral)?
Sunlight
Carbon Dioxide
Water
Nutrients
Glucose
Oxygen
Waste (nutrients)
Water
Heat
Energy transfer: In Photosynthesis and Respiration, energy changes forms but
does not get used up. It begins as light energy, then is converted into chemical
energy during photosynthesis (energy is stored in food), and is released into the
atmosphere as heat when respiration is complete.
Matter: Matter is anything with mass. All matter is recycled in the system.
Which type of symbiotic relationship do
coral and zooxanthellae exhibit?
MUTUALISM! They both benefit from the interaction in the following ways:
CORALS receive energy from zooxanthellae, which is stored in the glucose
that the zooxanthellae produce during photosynthesis. The rest of their
energy (and nutrients) is obtained from their food, zooplankton, which they
catch with their stinging tentacles. Corals need lots of energy to reproduce
new individuals that can add to the size of a reef.
ZOOXANTHELLAE receive protection from a coral’s hard skeleton and
stinging cells. Zooxanthellae also use some of coral waste as nutrients.
More interesting information about the relationship: Reef-building corals get
their coloration from the zooxanthellae in their tissues, so it is difficult to
identify coral species based on their coloration. When corals are stressed,
they release their zooxanthellae and become all white (what we know as
coral bleaching).
In the next two lessons we will learn more
about symbiotic relationships by looking at
actual research being conducting by
scientists on coral reef organisms.
End of Lesson
Vocabulary Check
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Zooxanthella (zooxanthellae = plural): A single-celled algae (dinoflagellate) that
can often be found living within the tissue of certain Cnidarians, especially reefbuilding corals.
Hypothesis (Hypotheses = plural): An educated prediction.
Ecology: The study of how organisms interact with each other and their physical
environment.
Barrier Reef: A reef that is parallel to the shore and usually separated from land by a
lagoon.
Symbiosis: A close relationship between two organisms. Many symbiotic organisms
share a living space.
Symbiont: Usually the smaller organism in a symbiotic relationship.
Host: Usually the larger organism in a symbiotic relationship.
Mutualism: A relationship between two organisms (host and symbiont) in which both
benefit from the interaction.
Parasitism: A relationship between two organisms in which one organism benefits at
the other organism's expense.
Commensalism: A relationship between two organisms in which the host neither
benefits nor is hurt by the relationship.
Producer: An organism capable of making its own food.
Photosynthesis: Process of using energy in sunlight to convert water and carbon
dioxide into carbohydrates (sugar, energy) and oxygen.
Chlorophyll: A specialized pigment found in producers that allows them to attract
and absorb sunlight rays.
Chloroplast: The organelle where photosynthesis takes place in a plant or algal cell.
Inputs: Resources organisms use to function.
Matter: Anything with mass.
Energy: Anything that can be converted into and measured as heat.
Work Cited
Text
Vocabulary and teaching techniques throughout this unit were adapted from:
1. Pottenger, F.M., Young, D.B., and Klemm, B.E. Matter and Energy in
the Biosphere: FAST (Foundational Approaches in Science
Teaching). Curriculum Research and Development Group, University
of Hawaii at Manoa,1978.
Photos
1.
Col, Jeananda. Enchanted Learning.
http://www.EnchantedLearning.com 1996 (slide 22).
2.
Mattia, Christopher. University of Maryland Center for Environmental
Science. 1997. www.cbl.umces.edu.
3.
Utah State Office of Education, http://www.usoe.k12.ut.us/ (slide 12).
4.
Santos, Scott R. State University of New York at Buffalo.
www.coral.noaa.gov (Slides 9, 23, 36, 39).
5.
Stewart, Hannah. Post-Doctorate Fellow. University of California,
Santa Barbara (Slides 3, 4, 5, 25, 26, 27, 29, 30, 31, 32, 37, 39).
6.
Withy-Allen, Kira. University of California, Santa Barbara and
University Laboratory School, University of Hawaii at Manoa (Slides
1, 9, 16, 24, 41).