8.2

Water uptake

Cambridge IGCSE Biology (0610)  · Unit 8: Transport in plants  · 8 flashcards

Water uptake is topic 8.2 in the Cambridge IGCSE Biology (0610) syllabus , positioned in Unit 8 — Transport in plants , alongside Xylem and phloem, Transpiration and Translocation.  In one line: Root hair cells primarily absorb water and mineral ions from the soil. Their elongated shape increases the surface area available for absorption, maximizing water uptake for the plant.

This topic is examined in Paper 1 (multiple-choice) and Papers 3/4 (theory), plus Paper 5 or Paper 6 (practical / alternative to practical). Past papers from 2022 to 2025 record 1 explicit question on this topic — though the concept underpins many adjacent topics, so it is tested far more often than that figure suggests.

The deck below contains 8 flashcards — 2 definitions, 4 key concepts, 1 process card and 1 application card — covering the precise wording mark schemes reward.  Use the 2 definition cards to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

The primary function of root hair cells

Root hair cells primarily absorb water and mineral ions from the soil. Their elongated shape increases the surface area available for absorption, maximizing water uptake for the plant.

What the Cambridge 0610 syllabus says

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. Identify Identify in diagrams and images root hair cells and state their functions
  2. State State that the large surface area of root hairs increases the uptake of water and mineral ions
  3. Outline Outline the pathway taken by water through the root, stem and leaf as: root hair cells, root cortex cells, xylem, mesophyll cells
  4. Investigate Investigate, using a suitable stain, the pathway of water through the above-ground parts of a plant
Definition Flip

What is the primary function of root hair cells?

Answer Flip

Root hair cells primarily absorb water and mineral ions from the soil. Their elongated shape increases the surface area available for absorption, maximizing water uptake for the plant.

Key Concept Flip

How does the large surface area of root hairs aid in water uptake?

Answer Flip

The extensive surface area provided by root hairs significantly increases the area available for osmosis. This allows for a greater volume of water to be absorbed from the soil.

Example: a single rye plant can have up to 14 billion root hairs, creating a vast surface area for efficient water absorption essential for photosynthesis and transpiration.
Definition Flip

What is the role of xylem in water transport?

Answer Flip

Xylem is the vascular tissue responsible for transporting water and dissolved mineral ions upwards from the roots to all parts of the plant, including the leaves. Xylem vessels are dead cells, forming continuous tubes.

Key Concept Flip

Describe the function of the mesophyll cells in relation to water.

Answer Flip

Mesophyll cells in leaves contain chloroplasts and use water absorbed from the xylem for photosynthesis. They release oxygen as a byproduct and also lose water through transpiration.

Key Concept Flip

What physical property of water is essential for its movement through xylem vessels?

Answer Flip

Cohesion is essential, allowing water molecules to stick together due to hydrogen bonds. Adhesion to the walls of the xylem also helps counter gravity and maintain a continuous column of water.

Key Concept Flip

What is transpiration?

Answer Flip

Transpiration is the loss of water vapor from plant leaves through stomata. The rate of transpiration is affected by factors such as humidity, temperature, and wind speed.

Key Concept Flip

Explain how a plant maintains a water potential gradient from the soil to the air.

Answer Flip

The water potential is highest in the soil and lowest in the air surrounding the leaf. Transpiration lowers the water potential in the leaf, creating a 'pull' that draws water up the xylem from the roots, maintaining this gradient.

Key Concept Flip

What method can be used to visually track water transport in a plant stem?

Answer Flip

A suitable stain, such as eosin or colored dye, can be added to the water supply of a plant. As the plant takes up water, the stained water will move through the xylem, making the pathway visible when the stem is cross-sectioned.

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8.1 Xylem and phloem 8.3 Transpiration

Key Questions: Water uptake

What is the primary function of root hair cells?

Root hair cells primarily absorb water and mineral ions from the soil. Their elongated shape increases the surface area available for absorption, maximizing water uptake for the plant.

What is the role of xylem in water transport?

Xylem is the vascular tissue responsible for transporting water and dissolved mineral ions upwards from the roots to all parts of the plant, including the leaves. Xylem vessels are dead cells, forming continuous tubes.

More topics in Unit 8 — Transport in plants

Water uptake sits alongside these Biology decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0610 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

root hair osmosis water absorption soil mineral ion active transport root cortex xylem vessel

Key terms covered in this Water uptake deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

The primary function of root hair cells
The role of xylem in water transport

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How to study this Water uptake deck

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