IB ESS · Topic 5 of 8

IB ESS Topic 5: Land

2 ready-made review sets for this topic, 21 questions in all, marked SL or HL, to play as a class game on the projector. Free to host, and students join with a code.

A question from the sets

Dark organic matter formed by the partial decay of plant and animal remains; improves soil structure and holds nutrients?

  • Soil
  • HumusRight answer
  • Leaching
  • Monoculture
From Topic 5: Land, 15 questions.

What Topic 5 covers

Topic 5 is soil and food. Soil is treated as a system with inputs, outputs, storages and flows: its profile and texture, what humus does, the work of detritivores and decomposers, how soil is degraded, for example by salinization and the leaching of nutrients, and how it is conserved. Then agriculture and food: food security, the Green Revolution, monoculture and its costs, malnutrition and sustainable diets. At higher level it adds the named soil horizons, and alternative approaches such as regenerative farming and permaculture, with practices like zero tillage and mob grazing.

  • 5.1 Soil
  • 5.2 Agriculture and food

Where students slip

  • Detritivores, such as earthworms, eat dead matter and break it into smaller pieces; decomposers, such as bacteria and fungi, break it down chemically and release the nutrients.
  • Leaching carries dissolved minerals down and out of the topsoil. It is not erosion, which removes the soil itself.
  • Irrigation in hot, dry places can cause salinization: the water evaporates and leaves its salts behind in the soil.
  • Food security is about everyone having reliable access to enough safe, nutritious food. A country can grow plenty and still have people who are food insecure.

The sets

Play this set opens the set in splycr, where you can read every question and host it for your class straight away. Hosting needs no account, and students join with the code on the board. A free account lets you copy a set and edit it.

The questions come from the Biology by Bradford flashcard bank. Each one plays as multiple choice, and the wrong options are other answers from the same set.

ESS has had a higher level course since the guide first assessed in 2026. Sets marked SL suit every ESS student, because higher level students study the standard level content too. Sets marked HL cover the additional higher level material in topics 2 to 8; Topic 1 has none, so its sets are all SL. The three HL lenses (environmental law, economics and ethics) have no sets yet.

Topic 5: Land

15 questionsSL

  1. Dark organic matter formed by the partial decay of plant and animal remains; improves soil structure and holds nutrients?

    Answer: Humus

  2. Organisms (e.g. earthworms) that fragment dead organic matter into smaller pieces?

    Answer: Detritivores

  3. Accumulation of salts in soil, often caused by irrigation, reducing fertility?

    Answer: Salinization

Play this setand 12 more questions

Topic 5: Land (HL)

6 questionsHL

  1. Top layer of a soil profile, made of leaf litter and partly decomposed organic matter?

    Answer: O horizon

  2. Farming that aims to rebuild soil organic matter, biodiversity and the soil's carbon store, rather than only sustain them?

    Answer: Regenerative farming

  3. Growing crops without ploughing, sowing seed directly into the remains of the last crop to protect soil structure?

    Answer: Zero tillage

Play this setand 3 more questions

Game modes that suit this topic

Every set plays in all eight modes. These two fit this topic best.

  • Racer solo

    In solo Racer the track is as long as the set, up to 12 cards, and one wrong answer sends a student back to the start, so finishing takes a full run of right answers.

  • Splycr

    A streak raises the multiplier to 3× and one slip drops it to 1×. Soil terms that look alike, such as detritivore and decomposer, are where streaks end.

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