Study Notes
Transport in plants involves the movement of substances like water, minerals, and food through specialized structures. Diffusion — the net movement of molecules from a region of higher concentration to a region of lower concentration down a concentration gradient. Example: Oxygen entering a cell through the cell membrane. Osmosis — the diffusion of water molecules through a partially permeable membrane from a region of high-water potential to low water potential. Example: Water entering a plant cell placed in pure water. Transpiration — the process of eliminating excess water from the plant body through evaporation from the leaves. Example: Water vapor leaving the leaf surface. Xylem — transports water and mineral salts from the roots to all parts of the plants. Example: Water moving up from roots to leaves. Phloem — transports food made in the leaves to all parts of the plants. Example: Sugars moving from leaves to roots.
Exam Tips
Key Definitions to Remember
- Diffusion
- Osmosis
- Transpiration
- Xylem
- Phloem
Common Confusions
- Confusing osmosis with diffusion
- Mixing up the functions of xylem and phloem
Typical Exam Questions
- What is diffusion? The net movement of molecules from a region of higher concentration to a region of lower concentration.
- How does osmosis differ from diffusion? Osmosis specifically refers to the movement of water molecules through a partially permeable membrane.
- What role does transpiration play in plants? It helps in the removal of excess water and aids in nutrient transport.
What Examiners Usually Test
- Understanding of how substances move in and out of plant cells
- Differences between xylem and phloem functions
- The process and importance of transpiration in plants