A technician investigated a mineral deficiency in bean plants. Fig. 1 shows two leaves, one from each treatment. Table 1 gives mean leaf area and the colour...
Question 1 Report
A technician investigated a mineral deficiency in bean plants. Fig. 1 shows two leaves, one from each treatment. Table 1 gives mean leaf area and the colour observation after 20 days.
| treatment | mean leaf area / cm2 | leaf colour |
|---|---|---|
| complete minerals | 34 | green |
| no magnesium | 18 | yellow |
(a) Which treatment produced yellow leaves? [1]
(b) Use Table 1 to calculate the difference in mean leaf area. [1]
(c) Suggest why a lack of magnesium reduces photosynthesis. [1]
(d) Describe how reduced photosynthesis can reduce plant growth. [1]
Fig. 1 shows an aquatic snail in a sealed jar with a water plant. A student used an indicator that changes colour when carbon dioxide is present. Table 1 shows the colour after 20 minutes.
| jar condition | indicator colour |
|---|---|
| lamp on | purple |
| lamp off | yellow |
(a) Name the process in the snail that releases carbon dioxide. [1]
(b) Use Table 1 to state which jar had the lower carbon dioxide concentration. [1]
(c) Describe why the colour in the lamp-on jar changed. [2]
Answer Details
Mineral deficiency
- (a) The treatment with no magnesium produced yellow leaves. [1]
- (b) \[34\text{ cm}^2-18\text{ cm}^2=16\text{ cm}^2\] The difference is 16 cm2. [1]
- (c) Magnesium is needed to make chlorophyll. A lack of magnesium reduces chlorophyll production and so reduces light absorption for photosynthesis. [1]
- (d) Reduced photosynthesis produces less glucose or carbohydrate, leaving less material or energy available for growth. [1]
Plant and snail jar
- (a) The snail releases carbon dioxide by respiration. [1]
- (b) The lamp-on, purple jar had the lower carbon dioxide concentration. [1]
- (c) With the lamp on, plant cells photosynthesised and removed carbon dioxide from the water or air in the jar. [2]
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