Every card in Ecosystems, Year 8: more practice
The whole deck, in order — so you can read it through before your child ever sees it.
- In a woodland, owls eat mice and mice eat seeds. A disease kills most of the owls. What will happen to the amount of seeds?
It will fall
HintFollow the change along the chain, one step at a time.
WhyFewer owls means fewer mice are eaten, so mouse numbers rise and more seeds are eaten.
- Why is a food web a better model of an ecosystem than a single food chain?
Most organisms eat more than one thing and are eaten by more than one
HintThink about real animals' diets.
WhyA web shows all the feeding links, so you can predict what happens if one species disappears.
- In a pyramid of numbers, what does the width of each bar show?
The number of organisms at that level
HintIt is a count, not a mass or energy.
WhyEach bar stands for one feeding level. A wider bar means there are more individual organisms at that level.
- Assume 10% of the energy passes to the next level. A plant stores 5000 kJ. How much energy reaches the primary consumer? (number only, in kJ)
500
HintFind 10% of the amount.
Why10% of 5000 is 5000 ÷ 10 = 500 kJ. The rest is lost as heat, movement and waste.
- Why are green plants called producers?
They make their own food by photosynthesis
HintWhere does a plant's energy for growing come from, if it never eats?
WhyProducers make glucose from carbon dioxide and water using light. All the other organisms in the chain depend on them.
- Which gas is released as a by-product when producers carry out photosynthesis?
Oxygen
HintAnimals need this gas to breathe.
WhyPhotosynthesis makes glucose and oxygen. Some of the oxygen is used by the plant and the rest is released into the air.
- Which two groups of organisms are the main decomposers?
Bacteria and fungi
HintOne group includes moulds and mushrooms.
WhyBoth feed on dead plants and animals. They release nutrients back into the soil for plants to use.
- Why do dead leaves rot faster in a warm, moist heap than in a cold, dry one?
Decomposers work faster when it is warm and moist
HintThink about conditions the microbes like.
WhyWarmth and moisture help bacteria and fungi grow and reproduce, so they break down material more quickly.
- A field has an area of 200 m². A quadrat covers 1 m². Daisies average 4 per quadrat. Estimate the number of daisies in the field. (number only)
800
HintMultiply the average per square by the number of squares that fit.
WhyDaisies per m² × area of the field = 4 × 200 = 800.
- Why should you take many quadrat samples rather than just one?
One sample might not be typical, so more samples give a more reliable estimate
HintThink about luck.
WhyA single square might fall on an unusually crowded or empty patch. Averaging many random squares evens that out.
1★ KS3-BIOL-ECO-0050
2★ KS3-BIOL-ECO-0051
3★ KS3-BIOL-ECO-0052
4★ KS3-BIOL-ECO-0053
5★ KS3-BIOL-ECO-0054
6★ KS3-BIOL-ECO-0055
7★ KS3-BIOL-ECO-0056
8★ KS3-BIOL-ECO-0057
9★ KS3-BIOL-ECO-0058
10★ KS3-BIOL-ECO-0059
Keep what you learn
Here, nothing is saved. In your child’s own sky every card is scheduled — it comes back just before they’d forget it — and the professor who wrote it is one tap away.