Competition and Cooperation (14:06)
Objectives
After viewing the video and participating in one or more of the Hands-On
Activities, students will be able to:
* model and/or explain the relationship between Sun, plants and animals as
"primary producers," "consumers" and "decomposers"
in the rainforest food web
* discuss examples of "mutualistic" relationships between plants,
insects, birds and animals
* describe specific physiological adaptations promoting mutualistic
relationships, for example, the specialized organs of ant-defended plants
| Program
Description This program shows both the "classic" food web in which some organisms gain energy by eating other creatures, but also shows the more recently recognized phenomena of mutualistic relationships, in which two or more organisms benefit from their interaction. The equation for photosynthesis introduces the factors which ultimately power the forest and the creatures who live there. (02:06) Oxygen released by green plants during photosynthesis has transformed our planet from one with an oxygen-poor atmosphere to one where all animals rely upon this gas-one more reason humans have a stake in what happens to the plants and forests of our world. |
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Vocabulary
Post-Viewing / Quiz Questions
Discussion Topics Hands-On Activities LIVE FROM THE RAINFOREST Teacher's Guide, page 64, Activity 3.3.3 The Breath
of Plants and the Life of the Planet (1/2 class period to set up, and 1/2 to
check and write up results) LIVE FROM THE RAINFOREST Teacher's Guide, page 62-3, Activity 3.3.1 Penciling
in the Carbon Cycle and Activity 3.3.2 Comparing Dry Ice and Water Ice as
demonstrations. Also seen demonstrated in Educator program B. Have students
record observations in their Logbooks and draw conclusions. (Both Activities can
be completed in 1 class period.)
If you have enough time students could also dissect Gladiolus to learn the
parts of the flower (relating to Emilio's comments about the need to place
pollen precisely in the heliconia) and how flowers are pollinated. This will
take one additional class period.
Online Review any questions that could be submitted to RESEARCHER Q&A.
Selected "NSES/2061 Benchmarks" met by the video, hands-on and
online resources Classroom Videos / In-service Videos / Implementation Guide / Hands-On Activities / Worksheets / Website / National Standards
*
"Heliconia and Hummingbirds" (04:02) Emilio Bruna describes
how his experiment mimics the reliance of this species of plant on this
particular bird species to disperse its pollen throughout the
rainforest. He notes that many other creatures rely in turn on the
heliconia-second most abundant plant in the Amazon rainforest understory
after the palms-for food.
* "Ant-Defended Plants" (03:07) Ecologist Susan Laurance shows
us two different species of plant, one of which has evolved small
structures which provide shelter for ants which patrol the leaves,
thereby warding off would-be herbivores. Another species of plant uses
some of its own precious supply of food-including the sugars produced
through photosynthesis-to enlist a small army of ants in its defense.
* "Dung, Beetles and Seeds" (04:35) One of the most unusual
and memorable experiments exploring mutualism is that of Ellen Andresen.
We see why she rises early to collect the dung of howler monkeys-yes, we
know some students will go "yuck!"-into which she then places
seeds attached to strings, in order to track how some beetles use the
dung as nutrient for their young, and so, like the hummingbirds,
disperse seeds throughout the forest.
Concepts photosynthesis, primary producer, consumer, decomposer, herbivore/herbivory,
mutualistic, stigma, nodule
Critters peccary, agouti, heliconia, howler monkey, dung beetle
Pre-Viewing Questions
* You may have heard the sayings "It's a 'dog eat dog' world" and
"Nature red in tooth and claw", both of which mean that in the natural
world it's a case of eat or be eaten. Do you think that this applies to the
rainforest?
* What celestial body and physical process lies at the heart of the rainforest
food web? (The Sun; photosynthesis)
* Explain that later in the Module they will be playing "The Tropical Food
Web Game," in which each student will represent a different plant or animal
in the rainforest. Have them view this and following programs as a way of
deciding which organism they'd most like to be.
* In addition to "eat and be eaten" what other kind of relationships
exist between organisms in the rainforest food web? Give examples. ("Mutualistic"
or mutually beneficial relationships, as seen in heliconia and humming-birds,
ant-defended plants, use of monkey dung by beetles, plant survival being
promoted through seed dispersal by dung beetles.)
* How do Emilio and Ellen mimic natural processes in order to create a more
controlled "natural" experiment? (Emilio by spreading pollen, and
Ellen by placing seeds in balls of dung.)
* How does the heliconia rely on hummingbirds? (To disperse pollen and so
fertilize other heliconia in the forest.)
* What are some familiar plants to which heliconia is related? (Bananas,
bird-of-paradise, ginger.)
* What are some of the things which plants offer ants in exchange for protection
against herbivores? ("Houses" in the nodules, and sugar-water food.)
* Why are a green plant's leaves important to humans-and why are they important
to the plant? (Plants produce oxygen in the process of photosynthesis, while
generating energy for their own survival.)
* What processes do we see whereby plants-rooted in one place-nevertheless
manage to disperse their seeds throughout the forest. (For the heliconia, via
hummingbirds; for some other plants, via monkey dung and dung beetles.)
* Sometimes nature is "red in tooth and claw": harpy eagles do swoop
down to eat small mammals. Can you think of a brand-new saying of a few words or
a snappy phrase to memorably sum up mutualistic relationships? "Nature-the
ties that bind"? We know you and your students could do better! (Could be a
homework assignment, after in-class discussion.)
* If humans rely on plants for oxygen, what do you think we should do about
deforestation? (Also applies to discussions of program 8.)
Remind them that later in the Module they will be participating in The Tropical
Rainforest Food Web Game (LIVE FROM THE RAINFOREST Guide, page 47) and that each
student will then represent a different plant or animal in the rainforest. Have
them think about which plant or animal they would like to be for the Activity,
but tell them you, the teacher, will need to make sure that the class, overall,
has a good sampling of plants and primary and secondary consumers so that they
may not "get" their first choice. They will need to research their
plant or animal for its prey/food and predator/what eats it, and any other
information they need to make connections during the Activity. You may wish to
have students choose the same plant or animal for their "A Day in the
Life..." report (LIVE FROM THE RAINFOREST Guide, page 22) and use the same
species for the food web Activity.
The Teacher Background provides useful information about how plants both respire
(giving off carbon dioxide) and photosynthesize (giving off oxygen.) This
classic Activity using Elodea should have a fresh impact in the context of the
rainforest. See Educator program B for a demonstration by teacher Pat Haddon,
and some tips about making sure you get enough oxygen to make a "pop."
Depending on class demographics (ages) and levels of responsibility, you may
choose to implement this either as a teacher demo or by student teams.
Go online to the PASSPORT TO THE RAINFOREST website to read Emilio Bruna's
JOURNAL "Heliconia and Other Plants" and Ellen Andresen's "Dung
Beetles and Howler Monkeys" in the RESEARCH/ers section.
6.3.4 Knows that multi-cellular organisms have a variety of specialized cells,
tissues, organs, and organ systems that perform specialized functions...
7.3.3 Knows ways in which species interact and depend on one another in an
ecosystem (e.g., producer/consumer, predator/prey, parasite/host, relationships
that are mutually beneficial or competitive)
7.3.6 Knows relationships that exist among organisms in food chains and food
webs