a.[1]
What name is given to a plant's growth response to unidirectional light? Select one option:
- Geotropism
- Hydrotropism
- Phototropism
b.[1]
Which plant hormone coordinates growth responses like phototropism by causing cells to elongate unequally on the shaded side of a shoot? Select one option:
- Auxin
- Gibberellin
- Ethene
c.[2]
A plant shoot grows towards a light source. Which two key processes or resources are directly enhanced or maximised as a result of this positive response? Select two options:
- Absorption of light
- Absorption of mineral ions from the soil
- Rate of photosynthesis
- Rate of anaerobic respiration
- Water uptake through the leaves
d.[5]
Plan an investigation to show the effect of unidirectional light on the direction of growth of germinating seed shoots (coleoptiles).
You should include:
- a control group or experimental setup comparison
- the measurements or observations you would record
- how you would control variables to ensure a valid investigation.
You may use the equipment shown in Figure 1 and any other standard laboratory apparatus.
