Quality Core Curriculum Objectives:

Science                                   (Inquiry)

#1 – Asks questions, makes/records observations, sorts objects,

communicates with others, makes predictions and inferences, makes sketches/diagrams,

uses tables and charts.

            #2 – Uses books and other media to obtain information.

            #4 -  Actively engages in learning via hands-on/minds-on science activities.

                                    (Life Science)

#23–Describes relationships in living communities.  Constructs a model/diagram of food web.  Describes disruption in web.

Language Arts                    (Listening/Speaking)

                #4 -  Recalls and interprets information presented orally.

            #6 – Responds to questions on orally presented material.

            #7 -  Increases vocabulary to reflect a growing range of knowledge.

                                    (Reference/Study)

#54- Uses guide words to locate information.

#55- Determines appropriate resource to answer specific questions.

Vocabulary:  symbiosis, commensalism, mutualism, parasitism

Method: Students research pairs of animals, play a card game, and classify the pairs of animals according to three major forms of symbiotic relationships.

Background:

Elements of any ecological system live in an intricate web of interdependence.  When two species of organisms live in close physical contact with each other, their relationship is called “symbiotic.”  There are three major forms of symbiotic relationships:

Commensalism:  A relationship in which one species derives food or shelter from another species without seriously harming that organism or providing any benefits in return.

Mutualism:  A reciprocal relationship in which two different species live in a symbiotic way where both species benefit and are dependent upon the relationship.

Parasitism:  A relationship between two species in which one species (the parasite) nourishes itself to the detriment of the other species (the host).

Materials:  cardboard or index cards for making cards, marking pens

Procedure:

1.      Make up several decks of cards (one deck for every five or six students).  Each deck should contain 16 card pairs of symbiotic relationships and one “no buddy” card.  Examples of pairs:

Barnacle/whale               cowbird/buffalo                    bee/marabou stork

Hermit crab/snail shell    aphid/ant                               pilot fish/shark

Oxpecker/rhinoceros      damselfish/sea anemone    gull/brown bear

Ostrich/warthog               yucca moth/yucca                 tick/dog

Ostrich/gazelle                 moth/sloth                              honey guide bird/badger    

      Cattle egret/cow (African Ankole)

2. Pass out a card to each student (do not include the “no buddy” card), and, by means of looking at a posted list on the chalkboard, have each student find his or her “buddy.”

3. These pairs of buddies should then research to find out why they are buddies, answering the following questions:  Why do we live together?  What advantages and disadvantages do we provide one another?  What would happen if one of us wasn’t here?” 

4.    Pairs of buddies then give short reports to the class, telling about their relationship.

5.    Divide the class into groups of five to six students each, and give each group a deck of cards.  Instruct the students as to how to play the game. 

6.    Deal out the cards.  Play starts to the left of the dealer and rotates in a clockwise manner.  Each player draws one card from the player to his or her left.  After the player has drawn a card, that player may lay down all cards in his or her hand which form symbiotic pairs.  When a player does not have any cards left in his or her hand, the game is over.  The player with the largest number of pairs at the end of the game is the winner.  One player is left holding the “no buddy” card at the end of the game.

7.      To culminate the activity, review the definitions above and go through the list of symbiotic pairs as a group to decide to which classification each pair belongs.  Stress that symbiotic relationships are just one example of the interdependence of all elements of ecological systems. 

Evaluation:

Give two examples of pairs of organisms, which have the symbiotic relationships of commensalism, mutualism, and parasitism.