8 mistakes learners make with ecosystems and food chains, each one named and explained.
The arrows in a food chain follow the energy, and the energy starts at the Sun.
A fungus that decays leaves is given as an example of a producer.
A fungus is not an animal, and producer is remembered as the group for things that are not animals.
Question. What a producer is
A common answer. a fungus that decays leaves
The answer. a green plant that makes its own food
Why. A producer makes its own food from light; a fungus feeds on material that is already there.
Ask whether it makes food or takes food. Only the makers are producers.
Producer, herbivore, carnivore or omnivore is matched to the wrong description.
Four similar words, all describing eating, learned in one lesson.
Question. An animal that eats both plants and animals
A common answer. a herbivore
The answer. an omnivore
Why. Omni means all, so an omnivore eats across the whole range.
The prefix does the work in each one. Herb, carn, omni.
Wind, or another physical process, is given as the origin of the energy in a food chain.
Wind carries energy, so it is not an unreasonable candidate if the Sun does not come to mind.
Question. Where almost all food chain energy starts
A common answer. the wind
The answer. the Sun
Why. Wind itself is driven by the Sun, and nothing eats wind.
Trace it back until you reach the step where energy enters life. That step is always the Sun.
The predator population is expected to rise when its prey disappears.
Fewer competitors sounds like good news, and the link to food supply is not the first thought.
Question. All the rabbits die, what happens to the foxes
A common answer. the fox population rises
The answer. the fox population falls
Why. The foxes have lost the thing they eat, so fewer of them can be fed.
Follow the arrow. If the energy supply falls, everything above it falls.
Removing one organism is predicted to leave the rest of the ecosystem unchanged.
Each organism is learned as its own box, and boxes look independent.
Question. All the rabbits die
A common answer. nothing else changes
The answer. the foxes decline and the grass spreads
Why. Every organism in a chain is somebody's food or somebody's eater.
Nothing in an ecosystem is only connected to itself.
Soil or water is given as where the energy in a food chain originally comes from.
Plants are watered and fed from the soil, and food is what you give something to make it grow.
Question. Where the energy in a food chain comes from
A common answer. the soil
The answer. the Sun
Why. Soil provides minerals in tiny amounts; the energy and the carbon come from light and air.
The mass of a tree comes mostly from the air, and all of its energy from the Sun.
A top predator is described as the biggest, or as always the smallest.
In the best known food chains the predator really is bigger, so size looks like the rule.
Question. What a top predator is
A common answer. the largest animal in the chain
The answer. the animal nothing else eats
Why. A stoat can be a top predator while being smaller than the rabbit it hunts.
Define by what eats what, never by how big it is.
The arrow is explained as pointing at what an animal eats, or as showing size or speed.
Reading left to right, grass arrow rabbit does look like a sentence about eating.
Question. grass -> rabbit
A common answer. the grass eats the rabbit, or the rabbit eats the grass
The answer. the energy moves from the grass into the rabbit
Why. The arrow points the way the energy travels, which is always up the chain.
Read it as gives energy to. The direction then makes sense every time.
WAJD spots these patterns in your child's answers and names the one behind their wrong answers, instead of just marking them wrong.