Dicot roots at Higher Level: The same statement as SL. HL papers link the root to phloem transport (2.7.18) and to root pressure (2.7.17).
Practise this as you read
- Identify the tissue that carries sap in a root micrograph.
- Draw a dicot root from a micrograph.
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it with your first topic free to keep:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Start Studying Free Full access to Aimnova Pro · cancel anytime
The big idea: In a dicot root all the vascular tissue is in one central stele: a star of xylem with phloem between its arms, inside a wide cortex.
| Tissue | Where | Main function |
|---|---|---|
| Epidermis | Outer layer, with root hairs | Absorbs water and mineral ions |
| Cortex | Wide band inside the epidermis | Storage; water passes through it |
| Xylem | Star shape in the centre | Carries water and minerals up; lignified |
| Phloem | Between the arms of the xylem | Carries sugars (translocation of sap) |
The points to remember
- Root: vascular tissue in the centre; stem: vascular bundles in a ring.
- Lignin is found in the xylem, at the centre of the root.
- The tissue adapted for translocation of sap is the phloem.
Remember it as: Root: star in the middle. Stem: ring of bundles.
Real example: the carrot. A carrot is a swollen root: cut one across and the pale central core is mostly xylem, surrounded by orange tissue that stores sugar.
Never wonder what to study next
Get a personalized daily plan based on your exam date, progress, and weak areas. We'll tell you exactly what to review each day.
Try Free Study PlanYour first topic is free to keep • No credit card required
Drawing it: Draw the root as outlines, in proportion: a thin epidermis, a wide cortex, a small central stele.
Two traps: Do not draw a ring of bundles: that is a stem. In a root the vascular tissue is in the centre.
The stele is small: keep the cortex much wider than the stele.
How it is asked: Expect a root micrograph with letters: which tissue has lignin, which carries water, which carries sap.
IB-style questionIdentify[1 mark]
The drawing shows a buttercup root in transverse section, with four tissues labelled A to D. Which tissue is adapted for translocation of sap?
Model answer plan
See the answer broken into clear points, with guidance on how each point earns marks.