Packed Lunch Food Chains

Source:

Isle Of May National Nature Reserve, Expedition Pack (SNH)

Time

10 - 15 minutes

You will need

packed lunches

Did you know?

All our food starts with energy from the sun - though scientists have recently found some deep ocean ecosystems that get their energy from hot sulphur gasses.

Before the activity

Eat the pack lunches!

The activity

Ask the class what they have eaten recently. Then ask if they can think of anything they have eaten recently that comes from the sun.

Did anyone eat crisps? Crisps are made from potatoes which need the sun’s energy to grow.
Sun > Potato Plant > Pupil

Did anyone eat some fruit? Fruit grows on plants which need the sunlight (energy) to grow.
Sun > Fruit Plant > Pupil

Did anyone eat a chicken sandwich? Chickens eat grain which need the sun’s energy to grow and the bread is made from wheat which also needs the sun’s energy to grow.

Sun > barley plant  > Chicken > Pupil     ;      Sun > Wheat Plant > Pupil

Did anyone eat chocolate? Chocolate comes from cocoa and milk. Cocoa is a bean from the cocoa plant. The plant needs the sun’s energy to grow. Milk is made by cows which eat grass which needs the sun’s energy to grow.

Sun > Cocoa Plant > Pupil ;    Sun > grass > Cow > Pupil

Explain that the energy, collected from sunlight by plants, passes from creature to creature until it reaches an animal on which no others feeds. These are called top predators such as humans, sea mammals, seabirds, etc. Now the class can work out some food chains for the wildlife they see around them.

How do the nutrients get passed back to the plants at the start of the food chain? Discuss the vital role of DECOMPOSERS (bacteria and fungi and animals which eat dead animals and plants).

Suggested follow up

Use the food chains to make a wall chart or frieze, back in the classroom , to illustrate the flow of energy around the ecosystem you visited.

Additional Information

Marine food chains are less obvious than terrestrial food chains, as the plants and herbivores are largely unseen plankton. Marine food chains start off with the sun just as with all food chains. Billions of phytoplankton (microscopic marine plants) float freely in the sea, drifting with the wind and tide and use the sun’s energy to make food. The phytoplankton (plant plankton) is then eaten by tiny herbivores (plant eaters) in the animal plankton (zooplankton). Other zooplankton are carnivores (meat eaters) and eat the herbivore zooplankton. Zooplankton is made up of all sorts of amazing looking creatures, some of which are the larval stages of bigger marine creatures such as crabs, lobsters, jellyfish, barnacles, etc. Plankton is one of the main sources of food (energy) in the sea. It is eaten by many marine creatures from barnacles mussels to fish and even whales.

Sun > Plant (phytoplankton) > Herbivore (zooplankton) > Carnivore (zooplankton) > Larger carnivores

Curriculum Links

Science - main

Age Range

2, 3,4