AQA Biology 4.7.1.2 and 4.7.1.3 · Combined and Triple

Abiotic and biotic factors

Eleven things that decide what lives where: seven non-living, four living. Sort them, then explain what happens to a community when one changes.

Combined Science · Higher tier

Start here

Field and wood.

Grasses and poppies fill an open field. Under the thick trees beside it, only ivy and moss grow.

If you had to guess, is it the light that makes the difference, or the animals?

Abiotic · non-living

Seven factors.

Abiotic factors are the non-living parts of the environment. The spec names seven. Tap each.

Biotic · living

Four factors.

Biotic factors come from other living organisms. The spec names four. Tap each.

A new disease arrives in a rabbit population and many rabbits die. Which biotic factor is this?

Pick one.

From data

Explain the effect of a change.

You should be able to explain how a change in an abiotic or biotic factor would affect a given community, given appropriate data. Name the factor, say which way it changed, then say what happened to the organisms and why.

Information · made-up data for practice

A stream is sampled above and below a pipe that releases warm water from a factory. Above the pipe: water 12 °C, dissolved oxygen 10 mg per dm³, 14 kinds of invertebrate. Below the pipe: water 24 °C, dissolved oxygen 5 mg per dm³, 5 kinds of invertebrate.

Which abiotic factor best explains the fall in the number of kinds of invertebrate?

Pick one.

Information · made-up data for practice

Light under a hedge was measured with a light meter at four points from the hedge into a field. 0 m: 200 lux, 2 plant species. 2 m: 900 lux, 5 species. 4 m: 2500 lux, 9 species. 6 m: 4000 lux, 11 species.

Which statement uses the data correctly?

Pick one.

How to measure light and count plants along a line is taught in Sampling techniques.

Think again · the fish or the oxygen?

“The fish dying is the abiotic factor.”

Your call

Choose

Oxygen in a river falls and fish die. Which is the abiotic factor that changed?

Sort

Abiotic or biotic?

Place each factor.

Tap a card, then tap the box it belongs in. Tap a placed card to take it back.

Command words in this lesson

Identify: Whether a factor is abiotic or biotic.
Explain: How a change in a factor affects a community, from data.
Describe: How a named factor affects organisms.

Key fact

Abiotic factors are non-living: light intensity, temperature, moisture, soil pH and mineral content, wind intensity and direction, carbon dioxide for plants, oxygen for aquatic animals. Biotic factors are living: food, new predators, new pathogens, one species outcompeting another.

Key note · AQA 4.7.1.2, 4.7.1.3

Abiotic and biotic factors

Abiotic (non-living) factors: light intensity; temperature; moisture levels; soil pH and mineral content; wind intensity and direction; carbon dioxide levels for plants; oxygen levels for aquatic animals.
Biotic (living) factors: availability of food; new predators arriving; new pathogens; one species outcompeting another so the numbers are no longer sufficient to breed.
To explain a change from data: name the factor, quote how it changed, then say what happened to the organisms and why.
The organisms that die are not the factor: the thing that changed around them is.

Photograph this card. Tomorrow, cover it and say each line first.

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Still calling the dying fish the abiotic factor?

The stream and hedge readings are made up for practice.