6.7 and 6.8 - Structure Adaptations Flashcards
What are root hair cells specialised for?
Root hair cells are specialised to take up water by osmosis and mineral ions by active transport from the soil as they are found in the tips of roots. They have a large surface area due to root hairs, allowing more water to move in.
What is the role of the large permanent vacuole in root hair cells?
The large permanent vacuole affects the speed of movement of water from the soil to the cell.
Why do root hair cells contain mitochondria?
Mitochondria provide energy from respiration for the active transport of mineral ions into the root hair cell.
What are xylem cells specialised for?
Xylem cells are specialised to transport water and mineral ions up the plant from the roots to the shoots. Upon formation, lignin is deposited, causing the cells to die and become lignified.
What happens to xylem cells when they become lignified?
They become hollow and are joined end-to-end to form a continuous tube for water and mineral ions to move through.
How does lignin help xylem cells?
Lignin is deposited in spirals, which helps the cells withstand the pressure from the movement of water.
What are phloem cells specialised for?
Phloem cells are specialised to carry the products of photosynthesis (food) to all parts of the plants.
What structures do the cell walls of phloem cells form?
The cell walls form structures called sieve plates when they break down, allowing the movement of substances from cell to cell.
Are phloem cells alive or dead?
Unlike xylem, phloem cells are alive.
How do phloem cells obtain energy?
The energy these cells need to be alive is supplied by the mitochondria of the companion cells.
What do phloem cells transport around the plant?
Phloem cells transport sucrose (the sugar that plants use) around the plant.
