Ecology and Environment
MYP Year 3 Sciences — Ecology and Environment
Ecology is the study of how living things interact with each other and with the non-living parts of their surroundings — get that one distinction wrong (calling water 'biotic' because fish live in it) and you'll lose marks on almost every question in this unit. Energy pyramids, food webs, pollution, conservation — every subtopic here is the same relationship (organism ↔ environment) examined from a different angle, usually via a pond diagram.
Overview
Why this topic keeps repeating itself
Every subtopic here is secretly asking the same three questions: what is present (biotic/abiotic components), how does energy move through it, and what happens when something changes. If you can answer those three for any diagram — a pond, a desert, a forest — you can answer almost any exam question in this unit, because ecosystem questions are diagram questions wearing different biomes.
The shape of the chapter
Command terms this unit tests hardest
| Command term | What it demands | AO | Mark-earning move |
|---|---|---|---|
| Identify | name/select the correct component or factor from a diagram or list | AO1 | 1 mark for the correct word only — no explanation needed or rewarded, so don't waste time justifying it |
| Describe | give a detailed account of WHAT happens, not why | AO2 | marks go for accurate detail, not mechanism — save the 'why' for an Explain question |
| Explain | give a cause AND its effect, explicitly linked | AO2/AO3 | the second mark is almost always for the linking word ('because', 'which means', 'so that') — two unlinked facts score half marks |
| Distinguish | state the actual point of difference between two similar terms | AO2 | defining both terms separately without contrasting them scores zero |
| Discuss | present multiple factors/sides with some evaluation | AO3 | one-sided answers cap at half marks even if factually correct |
| Suggest | apply science logically to an unfamiliar scenario | AO3 | no single 'correct' fact required — credit goes to a sensible, science-based justification |
Key point
Overview