Soil: JAMB Biology Questions, Answers & Notes

What Soil covers in the JAMB Biology syllabus

Soil is the loose top layer of the earth where plants grow. Its main types are sandy (large particles, drains fast, holds little water, warms quickly), clay (fine particles, holds water, drains poorly, can waterlog) and loamy (the best for crops — balanced drainage, aeration and nutrient retention); the mix of sand, silt and clay gives its texture. Soil contains mineral particles, water, air (oxygen for roots), humus (decayed organic matter that boosts fertility and water retention) and living organisms. Decomposers (bacteria, fungi) recycle nutrients; earthworms aerate and enrich the soil. Fertility is lost through erosion and leaching and maintained by manure, fertilisers, crop rotation and controlling erosion (cover crops, trees).

For Soil, JAMB expects you to be able to:

• Describe the types, components and properties of soil
• Explain the role of humus, decomposers and soil organisms
• Explain soil erosion, leaching and how to maintain fertility

Key facts & revision notes: Soil

These are the recurring points our Soil questions test — revise them until each feels automatic, then practise the questions above to lock them in.

• Soil is the loose top layer of the earth in which plants grow.
• The three main soil types are sandy, clay and loamy.
• Loamy soil is best for most crops — good drainage, aeration and nutrient/water retention.
• With large particles and big air spaces, sandy soil drains fast and retains little water.
• Fine clay particles pack tightly, so clay holds water well but drains poorly (can waterlog).
• Soil contains mineral particles, water, air, humus (organic matter) and living organisms.
• Humus is decomposed organic matter that enriches soil with nutrients.
• Humus improves fertility and helps the soil hold water and nutrients.
• Decomposers (bacteria and fungi) break down dead matter, recycling nutrients into the soil.
• Permeability (drainage) is how easily water passes through the soil.
• Waterlogging fills the air spaces with water, depriving roots of oxygen.
• Soil erosion is the removal of the fertile topsoil by wind or moving water.
• Leaching is the downward washing of dissolved nutrients out of the topsoil.
• Fertility is maintained by manure/fertilisers, crop rotation, and avoiding overuse.
• Cover crops, trees, terracing and mulching help hold soil in place and control erosion.
• Soil texture is determined by the relative proportions of sand, silt and clay.
• Sandy soil is light, warms quickly and is easy to work, though it holds little water.
• Soil air provides oxygen for root respiration and for soil organisms.
• Earthworms burrow (aerating the soil) and mix in organic matter, improving fertility and drainage.
• Soil pH measures how acidic or alkaline the soil is, affecting which plants grow well.
• The humus-rich topsoil is the most fertile layer.
• The subsoil lies below the topsoil.
• Sandy soil has large particles and drains fast.
• Fine clay holds water and can become waterlogged.

Worked examples

Three Soil questions with the answer and a short explanation, so you can see how the topic is set before you practise the full set.

How Soil is tested in JAMB Biology

Our Soil bank holds 40 questions (2 easy, 27 medium, 11 hard). JAMB Biology typically returns to Soil year after year, so steady practice on this topic is high-value revision. Questions are multiple-choice with four options, and at UTME pace you get roughly 40 seconds each — which is why timed practice matters.

How to answer Soil questions

Work the stem first and predict the answer before you look at the options; then eliminate the ones that contradict the key facts above. Watch for “which is not…”, “all of the above” and “except” style stems, which are where rushed candidates lose easy marks on Soil. If a calculation or a precise definition is involved, work it from first principles rather than guessing from a half-remembered rule. When two options look right, re-read the stem for the qualifier that separates them — JAMB rarely repeats an option by accident. If you are still unsure, eliminate the two weakest choices to lift your odds, flag the question, and move on; never burn a full minute on one Biology item when the exam gives you about forty seconds each. Then come back to flagged questions with whatever time remains. The single most reliable way to get faster at Soil is repeated timed practice, so use the button above until the recurring patterns feel automatic.

Common mistakes to avoid in Soil

The errors that cost marks on Soil are usually careless rather than conceptual: misreading a negative stem, confusing two similar terms, or rushing a definition you actually know. Candidates also over-rely on “expo” and last-minute cramming instead of understanding the topic — which fails the moment JAMB rephrases a familiar idea. Treat every option as a claim to be checked against the facts above, keep your working tidy for any calculation, and don’t change a considered answer on a hunch. Above all, revise Soil actively by answering questions, not just by re-reading notes — recall under time is what the exam rewards.

Frequently asked questions

Is Soil part of the JAMB Biology syllabus?

Yes. Soil is a recognised topic in the JAMB Biology syllabus, covering describe the types, components and properties of soil. You should be able to recall its key facts and apply them to multiple-choice questions.

How many Soil questions can I practise on Belmadeng?

There are 40 original, JAMB-standard Soil questions in our free bank, each with the correct answer and a worked explanation. You can practise them untimed or as a timed test.

What are the most important points to know about Soil?

Soil is the loose top layer of the earth where plants grow. Its main types are sandy (large particles, drains fast, holds little water, warms quickly), clay (fine particles, holds water, drains poorly, can waterlog) and loamy (the best for crops — balanced drainage, aeration and nutrient retention);…

How do I answer Soil questions quickly in JAMB?

Read the stem carefully, eliminate clearly wrong options, and match the remaining choices to the key facts for Soil. Practising timed Soil questions builds the speed you need for UTME's pace of about 40 seconds per question.

Are these JAMB Biology Soil questions past questions or original?

They are original questions written to JAMB (UTME) standard and mapped to the official syllabus — not reproduced past papers. This keeps them legal to use freely while closely mirroring how the real exam tests the topic.

Where can I practise Soil questions free without signing up?

Right here — tap “Start Soil practice” on this page to begin instantly. Belmadeng's CBT practice is completely free and needs no sign-up, download or subscription.

About these questions: original, JAMB-standard items written from the official UTME Biology syllabus (last reviewed 2026-09-18). Belmadeng is an independent study platform and is not affiliated with JAMB. Spotted an error? Use the report link.