Study Notes
Water uptake in plants involves the movement of water from the soil into the plant through root hairs, which increases the surface area for absorption. Water travels through the plant via a specific pathway to support various functions such as photosynthesis and temperature regulation.
- Root Hair Cells — single-celled extensions of root epidermal cells that absorb water and minerals. Example: Root hairs increase the surface area for absorption.
- Osmosis — movement of water from a region of high concentration to low concentration through a semi-permeable membrane. Example: Water moves from the soil into root hair cells by osmosis.
- Active Transport — movement of ions against a concentration gradient using energy. Example: Mineral ions enter root hair cells by active transport when soil concentration is low.
- Xylem — vascular tissue that transports water from roots to leaves. Example: Water moves through the xylem to reach the mesophyll cells in leaves.
Exam Tips
Key Definitions to Remember
- Root Hair Cells: Extensions of root epidermal cells that increase surface area for absorption.
- Osmosis: Movement of water from high to low concentration through a membrane.
- Active Transport: Movement of substances against a concentration gradient using energy.
Common Confusions
- Confusing osmosis with active transport.
- Misunderstanding the pathway of water through the plant.
Typical Exam Questions
- What is the function of root hair cells? Absorption of water and minerals.
- How does water move from the soil into the root hair cells? By osmosis.
- In which order does water pass through the cells of a plant? Root hair → root cortex → xylem → mesophyll cells.
What Examiners Usually Test
- Understanding of the water uptake process and pathway.
- Differences between osmosis and active transport.
- Adaptations of root hair cells for absorption.