Information on First Grade Curriculum.
I. Habitat: A place where a plant or
animal makes its home.
II. What is needed for a good habitat?
(Food, water, shelter, space)
Now let's tie everything
III. Before we do our activity, let's go
over the main habitats we have in the world. (Forest, desert,
ocean, under ground)
Give children pre-drawn pictures of the
habitats and let them draw in the appropriate animals/plants. If
you have time left, have volunteers explain their pictures and
why the animals fit into their habitats.
First briefly review last week and tie it into today’s lesson.
Ex: Now that you have learned about habitats and what animals need to survive, let’s learn how different plants and animals work together.
I. Community: consists of all living things, plants and animals, that share an
II. Sizes of different communities
III. Roles in a community
Every creature in a community has a role (the job one performs). Everyone in the community depends on one another to keep the community functioning well. What about humans? Do we depend on others in our community to survive? Do we make our own food or do we depend on someone else to make it for us? We need people in our community to make our food and clothes. People run businesses to supply others with what they need.
IV. Now that we’ve covered peoples’ roles in society, let’s learn about three very important roles in nature communities.
So now we have talked about big garbage collectors like vultures and little garbage collectors like ants and termites, but can you believe that garbage collectors can be even smaller than ants! Some we can’t even see without microscopes. They are called bacteria. Bacteria help break down dead and rotting material too.
What happens if you leave bread out on the counter too long or something in the refrigerator too long? What grows on it? Mold.
Mold loves to eat garbage and especially rotting fruits and vegetables. In the forest there are many types of molds and mushrooms that grow on the ground or on trees. Mushrooms are the most famous garbage collector of all. When they are alive, they eat all of the dead leaves, plants and animal material on the forest floor.
To illustrate the concept of communities, use the example of a bee community. Explain that in a bee community, each bee has a different role (similar to the ant community). The queen lays eggs, some worker bees collect flower nectar, some workers feed baby bees, and the male drones mate with the queen (they are the father bees). Most kids have some knowledge of bees so this makes the idea of an ecological community easier to understand.
The queen sits down and the workers pollinate flowers, gather pollen, and feed baby and queen. Explain how the community of bees depend on the community of flowers. (If teacher allows, consider playing the activity outside.)
What we are going to learn today ties in with habitats and communities, so let’s quickly review them.
I. Today we are going to learn about ecosystems. An ecosystem is the interaction/relationship between a habitat, its communities and environment.
II. Now let’s talk about how big an ecosystem can be.
III. We talked earlier about what plants and animals need to survive, so now let’s talk a little bit about how they use both living and non-living things to survive.
Plants use mostly non-living things like dirt, water, and sunlight. Animals on the other hand, use both. They eat the living parts of ecosystems and they drink the non-living part. Another thing plants and animals have in common is that they need certain temperatures to survive-not too warm or too cold. Every animal and plant has a certain temperature range it likes.
IV. There are many different ecosystems in the world like the rainforest, desert, artic, and rivers, but did you ever think that you have an ecosystem right in your backyard?
Activity: Web of life
This game will demonstrate that every part of the ecosystem is needed for the web of life to function. Each student will be a plant, animal, or component (so make sure there are enough roles that interconnect); they all hold onto string. First have one student let go and see what happens to the web of life. Then let a few more go until the web completely falls apart. Mix up the roles and have children form different patterns. The kids don’t need to stand in a straight line.
IV. Ecosystems Change: Daily, seasonally, through time
Temperatures change and the amount of light changes during the course of the day which affect plants and animals.
I. What are Endangered Species?
Because ecosystems change and humans damage the environment, animals are not able to find food and shelter. So they become endangered species. Let’s break these words down.
* You may want to ask them whether or not they know the words or can guess before defining them.
A. Species: A single type of plant or animal that can breed with another of its kind.
B. Endangered Species: A species that is in immediate danger of becoming extinct (no longer exists/completely gone from this planet).
C. Threatened Species: A species which is dying off and could become endangered.
All plants and animals are important. There is a connection between all different species and when it is broken, it affects everything else. For example, the endangered Southern Sea Otter is very important for other species and nature’s balance. When otters are hunted and removed from the coast, sea urchins-one of the otter’s favorite foods-will not be eaten. Then there will be too many sea urchins eating all of the kelp so the kelp forests that provide homes for other animals under water will disappear. It is like the ecosystem web of life activity that we did last week. When one person lets go of the string, the whole web falls apart.
So what’s the difference between an endangered species and a threatened species?
An endangered species is in immediate danger while a threatened species has a small population but won’t become extinct right away.
II. Ways of becoming extinct
People hunting them, pollution, etc. There are two main ways species become extinct. One is natural extinction and the other is human caused extinction.
Activity: Endangered Species Musical Chairs
III. Ways to help endangered species
People are trying to find ways to protect endangered species. A boy in Massachusetts stopped a housing project that would have destroyed the habitat of a rare turtle. Kids all over the world have raised money to boy rainforest land in Costa Rica to protect all of the plants and animals living there.
* Remember to thank teacher and class
Begin by asking the students what a cycle is. Encourage them to name some cycles in their everyday lives, (i.e. the cycle of the days-morning to night).
Ask students if they know what the water cycle is, and if so, can they explain it to the class. Write their ideas on the board.
Begin your explanation of the water cycle by showing the students the water cycle poster. Introduce the terms evaporation, condensation, precipitation, saturation, humidity and transpiration using the poster for each.
Evaporation: process by which water changes from a liquid to a gas.
Condensation: the process whereby water vapor in the atmosphere is returned to its original liquid state. In the atmosphere, condensation may appear as clouds, fog, mist, dew or frost, depending upon the physical conditions of the atmosphere.
Precipitation: All the forms of water that fall from the air to the Earth's surface are called precipitation.
Humidity: Some water in the form of invisible vapor is intermixed with the air throughout the atmosphere.
Use the posters illustrating how heat and cold affect water to explain these processes and the effects of temperature on the water cycle.
Ask the following questions to initiate thought about how water moves through the environment:
Preparation: Tape assorted pieces of construction paper in a random pattern on the ground outside or in a large room. Tape as many pieces of paper as there are students in the class.
Game: Outside or in a room with plenty of space, have the students find a piece of construction paper and stand on it with their arms outstretched. Tell them they are going to pretend they are a small cloud drop being blown about by the wind. When you say "go", have the students move from their piece of paper to another of the same color, keeping their arms spread out to their sides.
Each time one student touches another, they should grab hands as if they were becoming a larger cloud drop and continue moving on to a piece of paper which has the same color as the one from which they came. If students from two different colors should happen to collide en route, they should combine and move to the closest piece of colored paper. This will be the group's new color. Larger drops move about intermixed with smaller drops and keep combining in a similar manner. When a drop has five students in it, they have formed a raindrop and they should go to the puddle area and sit down. The puddle area is defined by a roped off area or hula hoop, located out of bounds. If drops combine to make a single drop of six or more students then it should divide in half, choose new colors, and remain moving throughout the cloud. Continue this game until the cloud is rained out and the puddle is full.
Using butcher paper and pens or crayons let the students draw their own water cycle, or if they want they may draw one large water cycle (they may also draw individual water cycles if there is no butcher paper).
While they are drawing continue to ask questions about how they fit into the water cycle.
Where does water go when it runs down the drain? Does it continue in the water cycle?
Where does the water that we drink come from? Do we collect rain?
* Remember to handout the WATER USE CHART worksheets to students; you will need to figure out the number of gallons that each student used in one day using gallon/minute rates. These numbers will be reported back to the class in the final visit. Remind the teacher to remind the class to bring the charts back to class for the next visit.
* You may also want to sing the water cycle song.
So far we have talked about the water cycle and how we get our drinking water. Today we are going to cover some of the main types of animals that live in water. How many of you have been to an aquarium? Gone snorkeling? Gone to the Six Flags Marine World Killer Whale and Dolphin shows? Those are probably the easiest ways to see water animals up close.
The largest category of water animals—Fish.
Does anyone know how a fish breathes? The fish takes water into its mouth. The water goes back through the gills. Then the gill cover at the side of the fish's head opens and the water runs out. This intake of water gives the fish oxygen. If a fish is out of water for a while, it will die because the gills will not work unless the fish is in the water.
There are many different kinds of fish. Some fish do strange things. And some fish look very strange.
What are some ways in which fish help us?
Are animals that live in water fish?
No. Whales, dolphins and seals are mammals. The sea turtle and other reptiles live in water.
Many amphibians also live in water.
Sharks are amazing fish that have been around since long before the dinosaurs existed. They live in waters all over the world, in every ocean, and even in some rivers and lakes. Unlike bony fish, sharks have no bones; their skeleton is made of cartilage, which is a tough, fibrous substance, not nearly as hard as bone. Sharks also have no swim bladder (unlike bony fish).
TEETH Sharks may have up to 3,000 teeth at one time. Most sharks do not chew their food, but gulp it down whole it in large pieces. The teeth are arranged in rows; when one tooth is damaged or lost, it is replaced by another. Most sharks have about 5 rows of teeth at any time. The front set is the largest and does most of the work.
Do sharks sleep? Fish don't sleep in the same way that we do, but they have active and inactive periods. Some sharks have been observed resting motionless on the sea floor. Others have to keep moving in order to breathe.
Whales breathe air. They are NOT fish. They are mammals that spend their entire lives in the water. Like all mammals:
dinosaurs were. They are also the loudest animal on Earth.
SWIMMING AND OTHER WATER ACTIVITIES Whales have a streamlined shape and almost no hair as adults (it would cause drag while swimming). Killer whales are the fastest, swimming up to 30 miles per hour (48 kph). Whales swim by moving their muscular tail (flukes) up and down. Fish swim by moving their tails left and right.
MIGRATION Many whales migrate over very long distances each year. They travel, sometimes in groups (pods), from cold-water feeding grounds to warm-water breeding grounds. Gray whales make the longest seasonal migration of any of the whales. They travel about 12,500 miles each year.
WHALE SONGS Complex whales songs can be heard for miles under the water. The humpback's song can last for 30 minutes. The songs are thought to be used in attracting mates, to keep track of offspring, and for the toothed whales, to locate prey.
Sea Turtles are large turtles that spend most of their lives in the seas. They live in shallow coastal waters of warm seas. All Sea Turtle species are considered endangered or threatened.
ANATOMY These cold-blooded animals are strong swimmers and good divers. They have four flipper-like legs and a shell that is attached to their backbone. They cannot pull their head and legs into the shell. These turtles vary in color from shades of brown to green to black. Sea turtles vary in size from 2 to 6 feet (0.5 to 1.9 m) long, weighing 78 to 1900 pounds (35 to 870 kg). During active times, turtles must go to the sea's surface every few minutes in order to breathe air.
DIET Most sea turtles are carnivores (meat eaters), Most sea turtles eat crustaceans (crabs, lobster, shrimp, and other shelled invertebrates), shellfish, jellyfish, and small fish.
REPRODUCTIONAdult female Sea Turtles return to the beach where they were born to lay up to 200 soft-shelled eggs in the sand. When the baby turtles hatch, they immediately head for the nearby water. Many young turtles are eaten by birds and other predators during this difficult trip.
Amphibians are vertebrates that spend part of their lives under water (breathing with gills) and the remainder on land (breathing with lungs). Amphibians are cold-blooded; their body temperature depends on the temperature of their environment.
There are three groups of amphibians. We’ll talk about 2:
Newts and Salamanders Salamanders are amphibians that retain their tail as an adult. They are animals that begin their lives in the water breathing with gills; as they mature, they develop lungs and breathe air. Salamanders look like lizards without scales.
Newts are brightly colored salamanders.
Frogs and Toads Frogs also spend part of their lives under water and the remainder on land. They have long, powerful jumping legs and a very short backbone. Most frogs have teeth (in the upper jaws only) but toads do not have any teeth.
Toads are nocturnal animals hunt at night and spend the day sheltered in a cool spot. Toads are like frogs except they spend less time in the water than frogs.
Five little speckled frogs,
Sitting on a hollow log,
Eating the most delicious bugs.
One frog jumped in the pool,
Where it was nice and cool.
Now there are four speckled frogs.
(Song continues until there are no frogs left).
Frogs are very different from many other animals. During their lives, they go through metamorphosis. This word, which is Greek, means "changes shape." A person is born as a baby, grows into a child, and then becomes an adult, but the person's body always looks relatively the same. Ask the students to compare how they look to how their parents look. Then introduce the frog's life cycle: Frogs lay eggs in a jelly-like substance. This keeps the eggs safe in the pond environment. The eggs are fertilized by the male frog after they leave the female's body. Frogs lay their eggs in clumps, toads in strings. Six to twenty days after being laid, the eggs hatch. Tadpoles come out! Discuss what tadpoles look like (most of the children will be familiar with tadpoles). After six to nine weeks of swimming around as a tadpole, legs sprout! The tadpole is preparing for life as a frog on land. Twelve weeks-- three months-- later, the tadpole looks like a grown frog, only with a remaining tail. Once the frog loses the last part of its tail, it is a fully grown frog! It will now find a mate and lay eggs, starting the life cycle over again. Compare the way the frog changes, from swimming tadpole with no legs to jumping frog with no tail, to the way non-metamorphic animals change. Several other animals that undergo metamorphosis include butterflies, mosquitos, and salamanders.
FROGS are also amphibians. This word means that they spend part of their life in water and part of their life on land.
Complete the frog life cycle on the velcro frog-life-cycle chart. Turn it over and introduce the life cycle of the mosquito. Mosquitoes are another animal that rely on a POND or PUDDLE for their life cycle.
Some interesting facts about frogs:
Ponds are a fantastic place to witness all kinds of animal life! Ponds are shallow, so water plants can grow all the way to the pond center. If the water is too deep for plants to grow, the water body is called a lake, not a pond. The water provides the perfect environment for metamorphic animals: dragonflies, frogs, salamanders, and mosquitos all begin their lives living in pond water. Ponds may look quite and still, but they are really teeming with life! Animals depend on ponds for water to live in and drink, and plants to eat. Some animals you might find living in or near ponds include crayfish, snails, salamanders, turtles, ducks, raccoons, deer, all sorts of insects, fish, birds, water striders, water beetles, snakes, geese, earthworms, and frogs!
The students will view the pond specimens: Murky water, frog eggs, tadpoles at different stages. They should write one or two sentences describing what they see, as well as a descriptive drawing.
by Kate Davis
I come from eggs like jelly.
I have a chubby belly.
My tail will disappear,
But I won't shed a tear.
I'll hip-hop when I grow.
What am I-do you know?
by Carol Quinn
In early spring
And swim 'round ponds
Where blackbirds sing.
As they go
Where turtles snap
And cattails grow.
Tadpoles change to
Hop out of ponds
To sleep on logs.
by Cynthia Cappetta
Who lives in a pond?
Little frogs green,
They croak as they catch
The bugs that they've seen.
Who lives in a pond?
Fish swimming around,
They're blue, gold, and green,
And they don't make a sound.
Who lives in a pond?
Yellow ducklings that quack.
They paddle their feet,
Moving forward and back.
(To the tune of The Farmer in The Dell)
To the pond we will go, to the pond we will go.
Hi ho the derry-o, to the pond we will go.
We'll see lots of frogs.
We'll see lots of frogs.
Hi ho the derry-o,
We'll see lots of frogs.
The fish swim around.
The fish swim around.
Hi ho the derry-o,
The fish swim around.
The water lillies bloom...
The dragonflies zoom...
The deer take a drink...
The ducks come to rest...
The turtles lie in the sun...
The water striders slide...
The water beetles dive...
The snails creep along...
The toads like to croak...
I have a little turtle,
He lives in a box.
He swims in the water
And he climbs on the rocks.
He snapped at a minnow
He snapped at a He snapped at a mosquito
And he snapped at me.
He caught the minnow,
He caught the flea,
He caught the mosquito,
But he didn't catch me! flea
Today we’re going to learn about the plant life cycle and plant parts.
Sun – outstretched arm with pointed finger like a sun’s ray
Rain – wiggle fingers as arms move downward
Air – arms move back and forth (or bodies run back and forth for a storm), accompanied by a whooshing sound
Seed – curl up in a ball on the floor. The seed has all the nutrients that plant needs to start sending up shoots and sending down roots. Send up a hand (shoot) and send out a leg (root). Uncurl and kneel-you’ve sprouted
Stem – Stand (or kneel) straight and tall. The stem provides the structural support for the plant so it doesn’t fall over. It also moves water and nutrients from the roots upward and sugars from the leaves downward.
Root – Wiggle your fingers-you grow lots of leaves. Stand up (feet together)- you grow taller. Spread feet apart- you spread out lots of roots. Wiggle your toes- you grow lots of little roots (rootlets). ‘Slurp, slurp’- your roots drink up water from the ground.
Leaf – Hold hands flat and palms forward on either side of face. Leaves are the food producing centers where they transform sunlight, water and air into sugar – food for the plant. They turn towards sun rays (act out a sun ray), and flutter in the wind (act out wind).
Flower – Hold hands with fingers spread wide over face. Hands are petals which then open and spread outward from face. Flower is the first step in making a new plant. The flower needs to get pollinated in order to produce fruit and seeds. A bee buzzes around and pollinates the flower (slap hands with kids). Uh, oh. Start scratching all over, you’re being attacked by insects and fungi.
Fruit – Form a large circle with arms over head. It has seeds inside (represented by the head). The fruit is often eaten by some animal and the seeds then get moved around by the animal to start a new plant. Or the fruit falls on the ground and the seed eventually comes out of the rotting fruit. Have fruits get plucked and eaten or fall and splat on the floor. Stick up one arm- a new seed sprouts from the ground where your tomato fell.
Take in soaked Lima Beans and show/explain different parts of the seeds.
Why do seeds need a coat? Explain that seeds have coats for the same reason we wear them—protection. We wear coats in the rain or when it’s cold to protect us from the elements.
The seed coat protects the inside of the seed which is where the baby plant is. Show the students how to split the seed in half. Make sure they open the rounded side, as not to damage the root and other internal plant structure. Look at the poster and find the same parts in the actual seed.
a) The biggest part of the seed is the cotyledon. The cotyledon is where food is stored, which feeds the baby plant before it reaches the light. Remind the kids that sunlight makes the plants grow, but when they are still underground, they need a different source of food. So each seed has its own little refrigerator underground: the cotyledons.
Q: Does the seed need the cotyledons once it has poked above the ground?
A: No, because the sunlight is now the plant’s food.
b) Look carefully on one end of the seed. You can see the beginnings of a root (technically the radical).
Q: What does the root do?
A: The little root will push the plant through the soil. It also soaks up water and nutrients in the soil.
Q: Which direction does the root go? Why?
A: It usually goes down in the soil, so that it can find water.
c) Next to the root, you can see small leaves.
Q: What do leaves do?
A: When they poke above the ground, they collect sunlight which makes them grow. The first leaves are usually bigger than the latter ones because they need to collect lots of sunlight.
*If time permits, go over the lima bean sequencing cards.
1. All the organisms out there in the world need energy to live, and today we are going to talk about where they get their energy from. Energy can come in many forms; one is the sun. Some organisms get their energy in the form of light.
Q. What can you think of that uses light to grow? (plants)
Plants get their energy from the sun. They can turn the energy in light into energy to grow tall. Plants are called producers because they produce their own energy. It’s easy to remember that plants are producers, because think of the produce section in the grocery store. What’s in the produce section? Plants, there are many different parts of plants there, fruits, and leaves, like lettuce. Plants are called producers because they make their own energy from something that is not living.
2. But not everyone can produce their own energy.
Q. Can you think of some organisms that can’t produce their own energy? (any animals, us, etc.)
That’s right, we can’t make our own. We eat instead. We have to get our energy from other objects. We can’t survive on rocks though, can we? We have to eat other organisms, living things. We can get our energy from other living things because they have already turned it into a form, like a fruit, a leaf, or meat, that we can use. Organisms who have to eat other living creatures are called consumers.
Q. Who can tell me what consume means? (to use up, to eat)
Animals are called consumers because they need to eat to get their energy. There are many different types of consumers. Some eat only plants (a consumer eating a producer), others only meat (a consumer eating a consumer), and some both.
3. There are also decomposers.
Q. Can anyone tell me what a decomposer is? (a decomposer breaks thing up, turns them back into soil)
Decomposers can be little tiny organisms like bacteria, or earthworms, or mushrooms and molds. Decomposers are a specific type of consumer. They need to consume other organisms, but they are different from other consumers because instead of using the energy to put into their own body they use a lot of it to break up dead matter. The dead matter could be from either a producer or a consumer. They are what turn your compost pile that started out as garden clippings and food, back into the minerals that make up soil.
4. All animals got their energy from the sun. Even if they don’t directly use the sunlight like producers do, without the sun they couldn’t live. This is because without the sun we wouldn’t have the producers, and without them there would be no energy on the planet in a form we animals could use. Sometimes it’s hard to see though, because the energy has passed through so many different organisms. But if you trace back what an animal ate, it will always come back to a plant, a producer.
Examples: A deer, a deer eats grass to get its energy, and grass got its energy from the sun, so the deer really gets its energy from the sun too. It’s just that the grass turned the sunlight into a form the deer could use. An owl, an owl eats a mouse, which ate some grass seeds. The owl also got its energy from a plant, which got it from the sun. Mold on your cheese, the mold lives off the cheese, which came from cow’s milk, and the cow survived by eating grass.
Q. What did you eat for dinner last night?
We can also trace that back to a producer. (go through a meal or two to prove it.) Producers are the foundation for all other living organisms. Plants need nothing living to grow, but they begin the energy cycle for all other living creatures.
Description: Children will pass around a skein of yarn which will demonstrate the interconnectedness of all life in the garden. Each child will have a garden food web card that will name an organism and what that organism eats and gets eaten by.
Background: In any ecosystem there are three types of organisms: producers, consumers and decomposers. This is as true in a healthy garden as in any other ecosystem. Producers, (plants) make their own energy from the sun. Consumers (which can be herbivores, carnivores or omnivores) eat the producers and each other. Decomposers feed on the dead matter and turn it back into nutrients which are taken up by the producers.
Follow up questions:
Plants need sun, water, soil and air. Today we are going to plant some seeds, and you can watch them sprout and grow. (If they’re radish seeds) And if they live long enough to form a radish, you can eat the radish. Then you are absorbing energy that started out as sunlight, and you can thank the radish for turning it into energy you can eat.
Give the kids their supplies and begin planting, outside is best. Make sure to tell them not to plant the seeds too deep in the soil, or they won’t get any light. And don’t mush the soil down, or they won’t have enough air. Water the pots so they’re moist, but don’t over-water them and drown the seeds, or they also won’t get enough air and sunlight.
Materials: trophic level pyramid boxes, posters.
1. Review the different levels of eaters.
2. These are called trophic levels. “Troph” means to eat; these are all different types of eaters. If you put each level on top of each other you get a pyramid (show poster with pyramid). This pyramid is called a “trophic pyramid.” Each level is on top of the one below it because it relies on that one for its energy.
Ask them to identify the different levels.
The pyramid falls apart, because there’s nothing to support the higher levels. This is because no organisms can survive
without the energy the producers make.
3. The trophic levels are in the shape of a pyramid because not all of the energy in one level goes on to the next level. Only about 10% of the energy in one level actually reaches the next one! The rest of the energy is lost before it moves to the next level. It doesn’t stay in the body of the organism so it doesn’t get eaten and passed on.
We use energy every time we move. This energy we can’t pass on to another trophic level, because it’s no longer in an object like an apple. It gets lost as motion/ movement, or heat; we also use energy to keep our bodies warm. Just like how light, also a non-object/matter form of energy started out the pyramid, these non-matter forms of energy are lost from it all the way up. This is why the pyramid is a pyramid instead of a “trophic square.” That’s why in a forest there are thousands of big trees, but only a few deer, and even fewer mountain lions. The weight and area taken up by the plants, the producers, is far greater than that taken up by the meat-consumers. As you move up the pyramid there are fewer and fewer organisms. One owl at the top is equal to 100 mice lower down. The majority of the energy the producers make never reach the top consumers, but it is that little bit that does which is the most important, because it lets those few animals survive.
The animal world is made up of carnivores (meat eaters), herbivores (plant eaters), and omnivores(food combiners which eat both plants and animals). Pretend you are an animal in the wild. You have to hunt for all your food. How long can you survive?
Have the kids all go to an open area, inside or outside, to act out the parts as you read the following: “We are Sun-Powered”
Curl into a ball and imagine that you are a tiny seed buried in the rich soil. The energy from the sun is stored inside your seed lobes and nourishes you as you begin to grow. Soon you burst open and your roots go downward, sucking in particles of water. Your shoot grows tall as it uses the sunlight energy to produce food out of water and air. A bug crawls through your grassy top, nibbling the green blades. Now the bug has absorbed the particles of sunlight, so become the bug. The bug crawls high on a blade of grass. A sudden burst of wind shakes the grass, and the bug loses its grip…and splash!! The bug blows away and falls in a stream. A fish underwater sees the rippling surface… and snap!! The fish eats the bug. Become the fish now, because the particles of sunlight are now part of him. A bear wades along the edge of the stream. He sees you swimming by and slaps his great paw into the water. Then, gulp! The bear swallows you up!!
Pretend to be the bear now, lumbering through the woods, because that is where the particles of light next travel. Quietly creeping through the woods is an Indian brave. He silently sets an arrow in his bow and lets it fly. The Indian has killed the bear. That night the bear meat is made into a stew and served at dinner.
Now you are an Indian sitting around a fire and the sunlight is a part of you. Where will it travel next? You can see that all animals are sun-powered, even ourselves!
Camouflage – Blending in with the surroundings in order to hide from predators or prey.
Carnivore – An animal that eats other animals.
Consumers – Animals, and in rare cases plants, that eat other animals and/or plants to fulfill their own nutritional energy requirements.
Decomposer – A living organism at the base of the food web that breaks down dead animal and plant litter into mineral rich humus (also called reducers).
Ecosystem – A specific geographic region characterized by the local landforms, the various plants and animals that live there, and the prevailing climatic conditions such as temperature and rainfall.
Food chain – The pathway by which organisms obtain, use, and transfer energy (Example plants are eaten by a grazing animal, and a larger predator eats the grazer; grass.rabbit.bobcat).
Food web – Multiple interwoven food chains (many different species of animals eat plants and many different species of predators eat grazing animals).
Herbivore – An animal that eats only plants.
Insectivore – Animals and plants that eat insects.
Omnivore – An animal that eats plants and animals.
Predators – Organisms that obtain their nutritional energy by killing and eating other organisms.
Prey – Any creature that is hunted and caught to be eaten for food.
Producer – Plants at the base of the food web that provide nutritional energy to herbivores and
predator-prey definitions 12 Sept. 03
Savannah River Ecology Laboratory [www.uga.edu/srel/]
Materials: food chain cardboard nametags, peanuts/raisins, posters
Last week we looked at trophic levels in a pyramid, but this week we're going to look at them in something else, the food chain. A food chain shows the links between the different trophic levels in a chain. It shows how all trophic levels are linked together in one cycle. If you are missing a link, you no longer have a chain, and the second half of the chain can't get the energy passing through the chain, because now there is a gap in it.
Don't use the whole class, but take about 7 students and assign a different trophic level to each one. Have them try to arrange themselves in the correct order and hold hands to form a chain. Demonstrate how if you remove one link of the chain, the rest can't get their energy. This is why it's important to have a large diversity of animals, you can't rely on just one or two at each trophic level, but you need thousands to be sure the chain is never broken.
You can also look at trophic levels in a food web.
Q. Does anyone know what the difference between a food chain and a food web is?
A food chain just looks at a single connection between each different trophic level, but a food web is a diagram which illustrates how there are multiple links between the different trophic levels. You can't really just connect all the trophic levels together in a single chain, but rather in many interconnected chains. An example are the decomposers, they don't just decompose a single trophic level, but every one. There are also animals like us who eat many different trophic levels.
Q. How many different trophic levels do we eat? (have the kids come up with a few) Show the food web posters to demonstrate the differences between a food web and a food chain. We could have you try to form a food web now, but that would get much more difficult than a food chain, because you would all have to hold about 4 other people's hands to show all the links. But you only have two hands each, so that won't really work will it? Instead you just have to imagine how no animal has a direct line back to the sun, they all rely on many more organisms than you can arrange in a single chain.
(This time with the entire class, it might work best to split into two groups, though, one with each of you)
Assign the students one level in a food chain beginning with the sun. Distribute the cardboard cutouts of their role in the food chain. Have the sun stand on a chair in the center with all the energy pellets (the raisins or peanuts, make sure no one's allergic to peanuts first, though). Now have all the students form a few different chains out from the sun, they may be branched, or a consumer may be connected to 2 lower consumers, etc. Have the sun pass 1-2 energy pellets to each plant participant, because the plants get their energy directly from the sun. Next have the primary consumers take the energy from the plants, and so on down the chain.
Q. What happens if there are not enough producers? What about an overpopulation of consumers?
This shows how everything within the trophic levels, food chain, and food webs are connected somehow. As the old Chinese proverb says, "if a person sneezes in Africa, it can cause a hurricane in Florida." In the food web this means, that even a small change in one trophic level can cause a big change on a different one. There is a finite amount of energy and it must be divided up in the structure of the food chains and food web.