Big Idea: Interdependence
Essential Understandings:
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Nothing stands alone—we need each other.
God designed all of creation with purpose and order.
Human health depends on biodiversity.
Populations, communities, and ecosystems are
interdependent.
Focus Questions:
 How are things interdependent?
 How do changes affect interdependence?
 Where do we observe God’s purpose and order?
Driving Question:
Why do we need
each other?
Supporting Question:
Learning Set 1: What is interdependence?
Lesson Title:
Lesson 3: What are different kinds of interdependent relationships?
OVERVIEW AND OBJECTIVES:
 Purpose
 Learning Objectives
 Assessment Criteria
To teach the children what symbiosis is, and what types of symbiosis exist in God’s creation.
VOCABULARY
PREPARATION
 Set-up
 Materials
 Special Considerations
 Time
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Links to Driving Question
Objectives: The children will be able to identify the terms symbiosis, mutualism, parasitism,
and interspecies competition and give examples of each.
Pre-Assessment: Teacher writes terms on the board in table form, and the children give oral
definitions as to what they think the terms might mean.
Symbiosis - describes close and often long-term interactions between different biological
species. There are different types of symbiosis:
1. Commensalism, in which one of the participating members benefits, but
the other does not, and there is no harm done to that organism.
2. Mutualism, in which both organisms benefit from the relationship.
3. Parasitism, in which one organism benefits while the other organism (the victim)
is harmed.
Time: 3 - 45 minute periods
Materials: Dictionary
Science Journal
2 books by April Pulley Sayre - Army Ant Parade and Splish! Splash! Animal Baths
National Geographic article: Article by Amy Sarver. Top-of-page photo © Frank
Lukasseck/zefa/Corbis. "Odd Couples" appears on pages 6-11 of our January-February
2006 issue.
Large pad paper, sticky notes
http://webecoist.com/2009/03/01/symbiotic-bird-animal-relationships/
7 wonders of the symbiotic world pictures and explanations – printed on card stock
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symbiosis is made up of interdependent actions
TEACHING STRATEGY
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Possible student
misconceptions
Readings and/or writing tasks
Pre-assessment - whole class
Read the 2 books to the whole class
National Geographic Article – Children in pairs read this with each other, new facts on sticky
notes, I wonder questions
Share and discuss sticky notes
Introduce the vocabulary – whole class – have kids apply examples to different terms
Look at card stock examples
“Types of Symbiosis” worksheet
Wrap up class discussion
1. The only type of animal interdependence is the biggest animals eating the smallest animals.
2. Group work will be fun and we won’t have to work very hard.
2 books by April Pulley Sayre - Army Ant Parade and Splish! Splash! Animal Baths
National Geographic article: Article by Amy Sarver. Top-of-page photo © Frank
Lukasseck/zefa/Corbis. "Odd Couples" appears on pages 6-11 of our January-February 2006 issue.
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Links to driving question
INSTRUCTIONAL SEQUENCE
 Introducing the Lesson
 Conducting the Lesson
 Concluding the Lesson
 Assessment
 Homework
Army ants, tropical
forests, and
symbiosis play into
this suspenseful
insect picture book.
Some animals help
other animals get
clean. What do they
get out of these
relationships?
http://webecoist.com/2009/03/01/symbiotic-bird-animal-relationships/
7 wonders of the symbiotic world pictures and explanations
Review meaning of the words “interdependence” and “interactions” as we go through the different parts
of the lessons.
1. Pre-Assessment: Teacher writes terms on the board in table form, and the children give oral
definitions as to what they think the terms might mean.
2. As the teacher reads the 2 books with the class, refer to the term “interdependent” often
3. National geographic article
 Kids in pairs receive copies of the article, a large white paper, and sticky notes
 For each section, the children choose one new fact and write it on a sticky note, and put it in
the “New Facts” column on the paper.
 Next, for each new fact, the children write an “I wonder” question and put the sticky note in
the “I Wonder” column on the large paper.
 Kids put their stickers on the white board and we discuss them – whole class
4. Science Journals: Kids look up the definitions in the dictionaries with a partner, leaving spaces
between definitions. Next, they think of some of the examples we have discussed.
5. After they are written, and teacher writes them on the board, we discuss which examples go with
which definition.
6. Read the card stock examples. Kids may act them out as teacher reads, then decide who benefits,
who doesn’t and which type of symbiosis is shown.
Assessment:
 Informal – Teacher walks around and talks with kids, anecdotal notes
 Divide kids into groups of 4
 Each group does the “Types of Symbiosis” worksheet, discussing each example
 If groups can’t agree, more than one choice can be written
 Whole class – go through the worksheet and discuss
http://magma.nationalgeographic.com/ngexplorer/0601/articles/mainarticle.html
Odd Couples: Some animals pair up with other kinds of animals. They are the odd couples of the animal world.
PAIRING UP FOR SUCCESS
Living in the wild can be hard. Finding food and staying safe aren't easy. Each day, animals struggle to survive in their habitats.
Not all animals get by on their own. Some animals form a close partnership with other kinds of animals. These pairings are called
symbiotic relationships.
In a symbiotic relationship, the animals depend on each other. One animal helps the other meet its needs. Sounds good, right? Not
always. Some animals are not very kind to their partners.
In some cases, one animal meets its needs but hurts its partner. Sounds crazy, but it does happen. Take ticks, for example. These
insects guzzle blood to live. To get blood, they attach themselves to other kinds of animals. Ticks do not help their hosts. Instead, they
can pass germs that cause disease.
In other relationships, animals don't treat their partners so poorly. Both animals benefit, or get help, from living with the other animal.
Check out how animals pair up to survive.
KEEPING CLEAN
Small animals called cleaner shrimps have found a way of helping fish at coral reefs. As their name suggests, the shrimps clean the
fish. Here's how it works.
The shrimps hang out at what scientists call a cleaning station. A fish stops by. Then a shrimp climbs onto the fish. The shrimp even
steps into the fish's mouth.
The shrimp uses its tiny claws to pick stuff off the fish's body. That can include dead skin, tiny pieces of food, and wee creatures that
can hurt the fish. The fish gets a nice cleaning. The shrimp enjoys a tasty meal of fish trash.
Small birds called plovers are also in the cleaning business. They have big customers—crocodiles. Crocs have long snouts filled with
sharp teeth. Cleaning them is tricky.
That's where the plover comes in. When a croc opens its mouth, the plover hops right in. The croc does not snap its snout shut. Instead,
it lets the plover eat small, harmful animals attached to the crocodile's teeth. The plover gets an easy meal. The croc gets clean teeth.
EASY RIDERS
Many animals have to chase after a meal. Not the oxpecker. Instead of swooping through the sky searching for insects, this bird catches
a ride aboard large animals from antelope to zebras.
Don't those animals mind carrying birds on their backs? No. You see, an oxpecker picks ticks and other pests off its buddy's body. That
helps the animal stay free of blood-sucking bugs. In exchange, the oxpecker gets plenty of food. It's a perfect partnership.
Egrets also hang out with large animals, such as hippos and rhinos. When those big beasts walk, their feet stir up insects and other
small animals on the ground. That means the egret doesn't have to look far for a meal.
SWEET SUCCESS
Some animals need each other because they like the same food. Take the honeyguide bird and the ratel. They live on grasslands in
Africa.
Both animals love honey. Yet each has a problem getting some. The bird can find a beehive, but can't open it. The ratel can open a
hive, but doesn't know how to find one.
So the two animals team up. The bird flies over the grasslands, looking for hives. When it spots one, it swoops down and makes noise.
The sound tells the ratel to come eat.
The ratel uses its sharp claws to tear apart the hive. It gobbles up most of the honey-covered mess. Then the honeyguide bird enjoys
finishing off the leftovers.
CLOWNING AROUND
Land and sky animals aren't the only ones that work together. So do some sea animals. One of the oddest couples is made up of the
sea anemone and the clownfish.
You might think sea anemones look like plants, but they are really hungry animals. They attach themselves to a rock or a coral reef.
There they wait for a fish to swim by. Then they sting it with their tentacles. The stunned fish is then pulled into the sea anemone's
hidden mouth.
Still, one daring fish makes its home among sea anemones. It's the clownfish. This orange-and-white fish isn't kidding around. Its body
is shielded by a thick layer of mucus. The slime protects the clownfish from the sea anemone's dangerous, stinging tentacles.
The clownfish is also a good neighbor. It helps the sea anemone by luring in fish. When a hungry fish spots a colorful clownfish, it darts
toward it. The clownfish safely swims under the anemone's tentacles. If the hungry fish follows, it gets stung. Then it becomes the
anemone's next meal.
The brave clownfish not only reels in fish food, it chases away fish that might eat an anemone. So the clownfish and anemone help keep
each other fed and safe.
A DIFFERENT WAY OF LIFE
All animals want to do one thing—survive in the wild. Some do that by living alone. Others live in flocks, herds, hives, packs, or schools.
Some animals, both large and small, know the best way to stay alive is to live with or near other kinds of animals.
At first glance, these teammates don't seem to make sense. If you look more closely, you'll soon learn that these animals help one
another find food, shelter, and safety. They make the most of their various differences. These unlikely partners pair up to get the most
out of life.
Article by Amy Sarver. Top-of-page photo © Frank Lukasseck/zefa/Corbis. "Odd Couples" appears on pages 6-11 of our JanuaryFebruary 2006 issue.
OPEN WIDE: A cleaner shrimp
reaches into a moray eel's
mouth. The shrimp uses its
claws to pick stuff off the eel's
body. That can include dead
skin, tiny pieces of food, and
even little creatures that can hurt
the fish.
BEST BUDDIES: An oxpecker stops for a bite to eat aboard an antelope.
The bird eats bugs that live and feed on the animal. It's a perfect partnership.
The bird enjoys an easy meal, while the antelope gets a good cleaning.
SUPER SLIME: A clownfish hides in a sea anemone. This sea anemone
might look like a plant, but it’s a meat-eating animal. It uses its poisonous
tentacles to kill fish. Luckily, the clownfish has a thick coat of mucus to keep it
safe.
1. Plovers and Crocodiles
It looks like something out of a storybook –
and in fact it can be traced back to accounts
told thousands of years ago – a crocodile
opens its mouth, invites a bird in before …
what? ::Chomp:: it swallows the sap alive?
Amazingly, the crocodile remains still while
the plover picks meat from its mouth. This
cleans the crocodile’s teeth and prevents
infection while providing a somewhat scary
meal for the hungry bird.
(Images via: WarrenPhotographic, EnjoyFrance, AboutAustralia)
2. Honeyguides and Ratels
The honeyguide bird has something of a
problem: it wants access to the juicy wax
insides of a honeybee nest but lacks the
ability to access it directly. It has learned,
however, to lead other predators to such
nests and then wait for the remains of the
spoils. The honey badger (or ratel, shown
above) is one such creature with which the
bird works in collaboration, but honeyguides
have also been known to lead humans to
find nests. One native population finds honey
three times faster because of these
incredible birds.
(Images via: UnderWater, Navy, Montanag, NashvilleZoo, NigelDennis, Wikipedia)
3. Egrets and … Everything Else
Egrets are strangely equal-opportunity
symbiotics – they will ride on the backs of
all kinds of large mammals, picking
parasites from their fur or skin to nourish
themselves, which, in turn, frees these
animals of their burden – often kicked up to
their backs while walking. Moreover, it is
suspected that egrets also are more
sensitive to changes in their surroundings
and vigilant than their steeds, making them
good at early warnings when it comes to
environmental predators or other dangers.
(Images via: DiegoPaccagnella and Angelfire)
4. Oxpeckers and Zebras
Oxpeckers, like egrets, free their furry
companions of lice, ticks and other
annoyances but of particular importance is
their flying scream when predators
approach – after all, zebras are more
susceptible than many large mammal
species (such as elephants and hippos
shown above) to potential aggressors.
However, their actions are not always
completely in the interests of their hosts:
they are suspected to sometimes nip open
wounds on a zebra’s back in order to
encourage more parasites to take root for
later meals.
(Images via: ArnoLouise, AllPosters, OurLivesatSea, Flickr and HGBirder)
5. Ostriches and Zebras
Oxpeckers aren’t the only birds that zebras
have been known to pair with – they also
are often found in the company of giant
flightless ostriches. Both of these species is
justifiably concerned with approaching
danger. Unfortunately, the ostrich has
terrible senses of smell and hearing and the
zebra has poor eyesight. Fortunately, the
zebra can smell or hear certain dangers
approaching while the ostrich can see
others. Both are prepared to warn one
another at a moment’s notice so they can
each flee as needed.
(Images via: Flickr, Corbis, GreenSpun and PicasaWeb)
6. Woodpecker and Tree Ants
No one knows for certain how the
arrangement works, but a certain species of
woodpecker and tree ant are known to call
temporary truces despite being mortal
enemies most of the time. The southern
rufous woodpecker and the black tree ant
are normally predator and prey – but when
the bird lays its eggs in the nest of the ants
an agreement is made, a non-aggression
pact of sorts, that protects the bird’s eggs
from attacks by the nest and the ants’ nest
from other birds while the chosen bird is
nesting there.
(Images via: WiseDude, KolkataBirds, Chandra and Wikimedia)
7. Meat Ants and Leafhoppers
Other forms of ants, including meat ants,
have been known to team up with other
species as well, including butterflies and
leafhoppers. Normally, meat ants are
vicious and territorial – feeding on dead
animals and forcing other species of ants to
stay out of their way and forage at night.
However, they make special exceptions for
certain other creatures of the trees and
skies that secrete substances they can feed
on – not only do they leave these partners
alive but they actually actively protect them
from predators as well.
(Images via: Wikipedia, Geocities and BrisbaneInsects)
Name:_________________________________
TYPES OF SYMBIOSIS
There are 3 basic types of symbiosis. Don’t forget that symbiosis is the relationship between two organisms of
different species that benefits one or both organisms.
M- Mutualism- a symbiotic relationship that benefits both organisms involved.
C- Commensalism- a symbiotic relationship that benefits one organism and the other is not helped or
harmed.
P- Parasitism- a symbiotic relationship that benefits one organism and the other is harmed.
Directions: Put the letter (M,C,P) by the statement that best describes the type of symbiosis.
____ 1. A tick living on a dog.
____ 2. The honeyguide bird leading the honey badger to the bees hive, both eat the honey.
____ 3. A tapeworm living in a 4th grade students intestines.
____ 4. A bird building their nest in a tree.
____ 5. The hermit crab carrying the sea anemone on its back.
____ 6. The bristle worm living with the hermit crab.
____ 7. Head lice living on a human scalp.
____ 8. Mistletoe putting its roots into its host tree.
____ 9. The ants and the acacia tree living together and both receiving benefit.
____10. The egret, an insect eating bird, graze near some herbivores mouth.
____11. Orchids growing in tall tropical trees, the trees are not harmed but the orchids get
sunlight.
____12. Bacteria living on a humans skin.
____13. The remora hitching a ride on a shark.
____14. Barnacles living on a whale.
____15. Bees and a flower.
____16. Bacteria living in the intestines of a cow to help it break down cellulose.
____17. The clownfish and the sea anenemoe.
____18. A sixth grader and their pet.
____19. The Rhino and the tick bird.
____20. The lichen- a close relationship of a fungus and an alga that benefits both.
http://www.mrtester.co.uk/pdf/SYMBIOSIS%20WORKSHEET.pdf