Systems in Organisms
MYP Year 1 Sciences — Systems in Organisms
Every question your teacher writes about this unit is really asking the same thing in disguise: how does the structure of a body part fit the job it does? A curved rib, a straight femur, a folded intestine wall — none of these shapes are decorative. Learn to read shape-to-function like that and you'll answer 80% of the exam questions in this bank without memorising a single extra fact.
Overview — How the Body's Systems Fit Together
A 'system' in biology is a group of organs that work together to do one job the body can't do with a single organ alone. No system on this list works in isolation — the skeletal system can't move you anywhere without the muscular system pulling on it, and neither of them can work for more than a few seconds without the respiratory and circulatory systems delivering oxygen. Examiners test this connectedness constantly: a question that looks like it's only about bones ('describe why the ribs bend a little') is actually testing whether you understand that the ribcage has to move and protect at the same time.
- Support systems (skeletal, muscular) give the body shape and let it move.
- Continuity systems (reproductive) keep the species going, not the individual.
- Balance systems (excretory, homeostatic) keep the internal environment stable no matter what's happening outside.
- Supply systems (digestive, respiratory, circulatory) get raw materials in and deliver them everywhere they're needed.
The shape of the chapter
Command terms this unit tests hardest
| Command term | What it demands | AO | Mark-earning move |
|---|---|---|---|
| Identify | Give a short, specific answer — a name, not a sentence. | Knowing & Understanding | One correct word/label = full marks; extra explanation earns nothing extra. |
| Describe | State what is happening in detail, using data or observations given. | Knowing & Understanding | Needs a full sentence that reflects the actual pattern/data — a bare label loses the mark. |
| Explain | Give reasons — the 'because' behind a fact. | Inquiring & Designing / Knowing & Understanding | Cause AND effect both need to be present; stating only the fact without the reason drops a mark. |
| Compare | Discuss similarities AND differences between two things. | Knowing & Understanding | One-sided answers (all differences, no similarity, or vice versa) cap the mark below full credit. |
| Suggest | Apply your knowledge to a new, unfamiliar situation. | Inquiring & Designing | Reward given for logical reasoning even if it isn't the 'textbook' answer, as long as it's scientifically sound. |
Key point
Overview