In the Classroom
How Does Our Ecosystem Work?
All living matter can be thought of as a reservoir of food energy – with organisms either producing it or devouring it. Energy is not lost; it just passes from one to the other.
MAKING FOOD
Show PowerPoint – What is an ecosystem? (TOOLBOX)
Only plants make food, they are called producers.
Outline to students the concept of food production as a process that uses energy from the Sun’s rays to make food as follows:
• Leaves absorb carbon dioxide from the atmosphere.
• Water and minerals are absorbed from soil by roots and pass up the stem to the leaves by veins.
• In the leaves, cells contain tiny structures, called chloroplasts, that use the energy from the Sun to make the plant’s food – called sugars.
• The plant stores these sugars in the leaves, stems, and roots, and uses the food energy to grow and make seeds.
• In the process, oxygen is passed into the atmosphere from the leaves.
WHO EATS IT?
Animals are unable to grow food directly from the Sun like plants. Instead, animals (including us) eat plants that contain the Sun’s energy (trapped as sugars), and are called consumers.
• Plant-eating animals are called herbivores.
• Animals that eat other animals for their food energy, are called carnivores.
• The food energy the carnivore eats has come from their prey animal; they are therefore called secondary consumers.
Activity
Students draw a plant, as in the PowerPoint, and label each process.
Activity
Watch the carnivorous Peacock Spider, using its food energy to attract a mate:
Activity
What do the Invertebrates eat?
Students research on the Internet what each of their invertebrate eats (as in the example below).
1. Draw up a T-chart in their science notebook, or use WORKSHEET 1, and record each animal as ‘herbivore’ (and what part of a plant is eaten), carnivore (eating other animals), omnivore (eating both plant and animal), detritivore (eating decaying matter).
2. See WORKSHEET - Omnivores, carnivores, herbivores (Yrs 4-5, Coolbellup Community School) in TOOLBOX.
3. These data are used for making connections in the ecogram.
Activity
What do Students Eat?
1. Draw up a Table on the screen, with the 3 categories, herbivore, carnivore, and omnivore.
2. Ask each student to classify their diet as originating from plants (vegetables, fruit, seeds, etc.), or from an animal (meat, eggs, milk, invertebrates), or from both plant and animal origins (omnivore).
3. Add their name to the appropriate column.