Starter quiz
- What is the process by which water moves into the roots of a plant?
- diffusion
- condensation
- evaporation
- osmosis ✓
- active transport
-
- True or false? Osmosis is a type of diffusion.
- True ✓
- False
Match the cell part to its function.- A⇔provides support and structure ✓
- B⇔controls what enters and leaves the cell ✓
- C⇔the site of photosynthesis ✓
- D⇔contains cell sap (water and other substances) ✓
- Which tissue inside a plant transports water?
- 'Xylem' ✓
- Which three of the following statements about diffusion are true?
- The particles are constantly moving in random directions. ✓
- There is an overall net movement of particles from a low to high concentration.
- Diffusion requires energy.
- Diffusion is a passive process. ✓
- There is an overall net movement of particles from a high to low concentration. ✓
-
- A concentration ______ is a measurement of how the concentration of something changes from one place to another.
- 'gradient' ✓
Exit quiz
Match the part to its function.- a⇔eyepiece lens: viewing lens with ×10 magnification ✓
- b⇔objective lenses: three lenses with different magnifications ✓
- c⇔stage: specimen on a slide is placed here ✓
- d⇔light source: illuminates the specimen so that it can be observed ✓
- e⇔coarse focus wheel: for adjusting the focus in larger increments ✓
- f⇔fine focus wheel: for adjusting the focus in smaller increments ✓
Put these steps in the right order to show how to use a light microscope.- 1⇔Select the lowest power objective lens.
- 2⇔Place the slide on the stage.
- 3⇔Turn on the light source.
- 4⇔Look from the side, turn the coarse focus wheel to move the stage up.
- 5⇔Look into the eyepiece lens, turn the coarse focus wheel to move the stage away.
- 6⇔Look into the eyepiece lens, turn the fine focus wheel to make the image clear.
- What is plasmolysis?
- water moving from a high to a low concentration
- when a cells membrane pulls away from the cell wall ✓
- when a cells membrane pushes against the cell wall
- water moving from a low to a high concentration
-
When plant cells gain water, the vacuole fills up and becomes....- flaccid
- turgid ✓
- wilted
-
- ______ is the movement of water from an area of high water concentration to an area of low water concentration through a selectively-permeable membrane.
- 'osmosis' ✓
- What is the net direction of movement when the concentration of water molecules is greater inside the cell compared to outside the cell?
- into the cell
- out of the cell ✓
- no net movement
-
Worksheet
Presentation
Video
Lesson Details
Key learning points
- Use a light microscope to observe effects of osmosis in plant cells (including: shrinking/crenation, swelling/bursting)
- The parts of a light microscope and their functions.
- The sequence of steps for setting up a light microscope to observe cells, including changing magnification and focus.
- Explaining observations from microscopy using ideas about osmosis and net movement of water into/out of cells.
Common misconception
The process of osmosis, the direction of movement from high to low water concentration, and the effect that this has on plant cells in terms of turgidity and flaccidity are frequently confused.
Errors are explored, explained and questioned, and clear demonstrations of turgidity and flaccidity and the effects that these have on a plant are demonstrated. This will be reinforced by observation of these processes using a light microscope.
Keywords
Light microscope - an instrument that uses visible light and lenses to magnify viewed objects
Selectively-permeable membrane - a membrane that will only allow some substances through and not others
Osmosis - the net movement of water molecules from high to low concentration through a selectively-permeable membrane
Turgid - a cell which is swollen with water and firm
Flaccid - a cell which has lost a lot of water and is soft and limp