1. Science Focus Lesson Week 7
Elementary Science
Science
Focus Lesson
Week 7
Polk County Public Schools
Linda Vendur, Senior Coordinator

2. Week 7 – SC.F and SC.B.1.2.1
Benchmark:
SC.F The student knows how all animals depend on plants.
SC.B The student knows how to trace the flow of energy in a system.
Essential Question:
How does energy move through an ecosystem?
Vocabulary:
food chain decomposer
producer food web
consumer

3. SC.F.1.2.2 The student knows how all animals depend on plants.
All organisms need energy.
The sun is the main source of energy for Earth.
Through photosynthesis, plants convert energy from the sun into food. Animals depend on plants for their food.
It what other ways do animals, including people,
depend on plants?
Talk it over with your shoulder partner.

4. Animals Need Plants
Can you think of some ways animals depend on plants for….
shelter
oxygen to breathe
medicine
Source of water
Possible answers…
Shelter
Kelp beds – fish
Tall grasses – snakes, alligators, insects
Trees – squirrels, birds
Oxygen to Breathe
Plants make oxygen as a by-product of photosynthesis which all animals, including humans, use to breathe.
Source of water
Cactus are a source of water for desert animals.
Medicine
Many medicines come from plants.
Food for energy
Plants are the producers. All food chains begin with plants which convert the sun’s energy, through photosynthesis, into a source of energy we can use.
Protection
Many animals use plants to hide them from predators. Some climb trees to keep them away from predators.
Food for energy
Protection

5. Summarizing Answer the question in your Science notebook.
What are some ways animals depend on plants?
Give some examples.
How do you depend on plants?

6. Pass the Energy
The path of energy from one organism to another is called a food chain.
Food chains overlap to make food webs.
Think about what you ate for your last meal. Can you trace your meal back to the sun?

7. Links in the chain…
Producers are organisms that use the sun’s energy to make their own food. Plants are producers.
Consumers are organisms that cannot make their own food. They get their energy to stay alive and grow by eating other organisms. All animals are consumers.
The arrows show how energy flows through an ecosystem.
Why is the grasshopper the primary consumer?
IMPORTANT: Emphasize that the arrows show the FLOW OF THE ENERGY THROUGH THE SYSTEM. Often on assessments students get the flow backwards because they are thinking in terms of who eats who…wrong direction!
Energy
Energy
Energy
Primary
consumer
producer
consumer
consumer

8. Decomposers
Decomposers are organisms that get energy by feeding on dead materials and wastes. By doing this, they break material into smaller pieces and put it back into the soil.
Bacteria, mold, mushrooms, earthworms, centipedes, and slugs are all decomposers.
When you see something decaying or rotting, decomposers have been at work.
How do decomposers help recycle
minerals and nutrients?
Decomposers make minerals and nutrients that were in dead materials or waste available to living plants. There is a constant cycle of minerals and some nutrients moving from living things to the soil and back into living things.

9. Summarizing
What would happen to life on Earth if there were no producers?
Write your answers in your
Science notebook.
Students should understand that without producers to convert sunlight into energy that other organisms can use, life on Earth would not be possible.

10. SC.B The Flow of Energy
A food chain shows how energy moves through a system. The energy flows from the producer to the consumer. The arrows show the direction the energy moves through the system. In a food chain the primary role of an organism is to provide energy for other organisms.
Make sure students understand that the arrow represents the direction in which the energy is flowing.
On the NAEP 50 % of the students select the answer showing the opposite…
Fox Rabbit carrot (this is who eats who, not the flow of energy)
This is also covered under SC.F Food Chains 10

11. Each living thing in a food chain plays a role in the
flow of energy in an ecosystem.
The carrot provides energy for the rabbit and the rabbit provides energy for the fox.
What is the primary role of the rabbit in this
food chain?
A. to form a habitat
B. to find a space to live
C. to be a source of water
D. to be a source of energy

12. Yes! D is correct!
What is the primary role of the rabbit in this food chain?
While animals have many different roles in life, in a food chain the primary role of the prey (the rabbit) is to provide energy for the predator (the fox).
The energy from the prey is passed to the predator. Pass the Energy, Please!

13. Food manufacturing starts with a seed, And energy waits in a plant to be freed. Like an engine that powers the rest of a train, A plant’s the first link in an energy chain. Each creature that feeds on a plant is a link, Absorbing energy, quick as a wink. If that feeder, itself, becomes someone’s next meal, It lengthens the chain, like a new link of steel. And so there’s a pattern of energy passed: A food chain has formed, first hitched to last. Each living thing is a link in a chain with a purpose that Nature can always explain. From Pass the Energy, Please!

14. Discuss these questions with your shoulder partner.
Where does a food chain always start?
Why does the poet compare a plant to the engine of a train?
What does an animal get from a plant when it eats it?
Why do we call the process a “food chain”?
What is the “pattern of energy passed”?
How are all the plants and animals in a food chain linked together?
In reality the food chain always starts with the sun, but often the first link will be shown as the producer. In multiple choice items, students can easily eliminate choices that don’t have either the sun or a producer as the first link. There should be a clear understanding that energy from the sun is captured by producers and made into food. Producers are plants, grass, algae, some bacteria. 14

15. Summarizing
In your Science notebook draw a food chain you might find in nature.
In your food chain draw and label
a producer, two consumers
and a decomposer.
Explain how the energy
flows through the food chain.

16. 1. Safara cuts out these pictures from a magazine
1. Safara cuts out these pictures from a magazine. She must use all four of them to make an example of a food chain.
Part A Using words, show a food chain using all of Safara’s pictures.
Part B Explain the transfer of energy between all four of the organisms in your food chain.

17. 2 A. Identify the decomposer, producer and the consumers. B
2 A. Identify the decomposer, producer and the consumers. B. Explain the transfer of energy in this system? C. Where do the tree leaves get their energy?
Decomposer – bacteria
Producer – tree leaves
Consumers – deer, wolf, vulture
Students need to understand that not all consumers actually kill the food they eat. Some are scavengers, such as the vulture, which preys on wounded on dead animals.
In this example the bacteria is the decomposer. Decomposers don’t make their own food or eat living organisms. They feed on dead plants and dead animals. When the vulture dies (or any other plant or animal) the bacteria breaks down the dead materials into simpler materials which enter the soil and can be used by plants to grow.
Make sure students understand that the energy flows in the direction of the arrows.
Students need to understand that plants use energy from the sun to produce food through photosynthesis. 17

18. 1. Energy Flow in the food chain
Part A. sun corn chicken human Part B. The energy from the sun is used by the corn to make food. That energy is transferred to the chicken when it eats the corn. The energy from the chicken goes to the human when he eats the chicken. 18

19. 2. A. Decomposer – bacteria (Bacteria decomposes the vultures remains after it dies.)
Producer – tree leaves
Consumers – deer, wolf, vulture (The deer would be the primary consumer since it eats the leaves.)
B. The energy flows from the tree leaves to the deer when it eats the leaves. The energy then flows from the deer to the wolf when it eats the deer and from the wolf to the vulture when the wolf dies and its body is eaten by the vulture. The energy then moves from the vulture to the bacteria when the vulture dies and its body is decomposed by bacteria. The bacteria will return the minerals and nutrients back into the soil for plants use as they grow.
C. The tree uses energy from the sun to produce food through photosynthesis.

20. Summarizing Answer the Essential Question
for this lesson in your notebook.
Essential Question:
How does energy move
through an ecosystem?