Transport in Plants Flashcards
What is osmosis
Osmosis is the net diffusion of water molecules from an area of high water potential to an area of low water potential through a partially permeable membrane
What is diffusion
Diffusion is the net movement of particles due to their kinetic energy from an area of high concentration to an area of low concentration (down the concentration gradient).
Why does the water move into a visking tubing filled with a concentrated solution of sucrose, when it is dipped into a water solution
The water moves into the tubing because there is a higher water potential outside the tubing than the inside of the tubing. Therefore, the water molecules move from a higher concentration to a lower concentration via osmosis, through the partially permeable membrane of the tubing.
What is the water potential?
The water potential is how “free” the water molecules are to move around the solution.
ex: Pure water has a higher water potential than polluted water.
What happens when you put Red Blood Cells into a dilute solution of water
When you put RBC into a dilute water solution, the water potential outside the cells is higher than the water potential inside the cells. Therefore, the water located outside the cell will start to diffuse through the membrane and into the cell via osmosis. This makes the RBC swell up and even burst.
What is turgor in plants
This is when the pressure inside the plant cells pushes against other cells in the plant to support the non-woody parts of the plant. like: the stem, leaves. These also help to keep the leaves upright to be exposed to the maximum amount of sunlight.
Why is there no skin left on the potato tuber during the potato tuber experiment
There is no skin left on the potato tuber because the skin is not permeable to water, which prevents osmosis from occurring.
How does the root hair cells uptake water
The water in the soil has some mineral ions and solutes dissolved in it. But the concentrations of these solutes are much less than the concentration inside the root hair cell. Therefore, there is a greater water potential outside the root hair cell than inside the root hair cell. This causes the water in the soil to diffuse through the cell membrane and into the root hair cell via osmosis. This causes a greater water potential inside the root hair cell and the water will diffuse the cortex of the root and finally reach the xylem via osmosis, where it will be sent throughout the plant.
What are the uses of the transpiration stream
- It delivers the ions that are stored in the water to the other parts of the plant.
- It brings water towards the leaf cells to carry out photosynthesis.
- It helps keep plant cells turgid, to maintain the shape of the plant.
- Allows the water to be evaporated from the surface of the leaf, which causes a cooling effect on the leaf.
What is the purpose of the Xylem
It transports the water and mineral ions from the roots to the other parts of the plant, including the leaves.
What is the purpose of the Phloem
It transports the products produced in photosynthesis in the leaves of the plant to the other parts of the plant that cannot carry out photosynthesis.
What cells are the Xylem made out of (dead or alive) ?
Dead
What cells is the Phloem made out of (dead or alive) ?
Alive
What are the differences between the Xylem and the Phloem
- Xylem carries its material in one direction, while the phloem carries its material in both directions.
- Xylem carries mineral ions and water, the phloem carries the products of photosynthesis.
- Xylem consists of Dead cells, the phloem consists of living cells.
- Xylem walls have lignin, phloem walls do not.
- Phloem has companion cells, while xylem does not.
Where is the Vascular Bundle situated in the stem
Around the edge in a circle
