CAIE A-Level Biology A2 13.2.4 Whole Plant Photosynthesis Investigation Questions
Explain whole-plant photosynthesis investigations using evidence from each question and mark scheme.
- Syllabus
- 2028–2030
- Course
- Biology 9700
- Level
- A2
Exam points
- Explain whole-plant photosynthesis investigations.
CAIE A-Level Biology A2 13.2.4 Whole Plant Photosynthesis Investigation Questions question 1
Fig. 4.1 shows a diagram of a stoma, its guard cells and adjacent epidermal cells.
Fig. 4.1
Question (a)
(a)
The following experiment was carried out to investigate the effect of light intensity on the rate of photosynthesis of a water plant, Elodea.
- Elodea was cut into three pieces, each 10 cm long.
- Each piece of Elodea was placed in a glass tube, containing 0.5 % sodium hydrogen carbonate solution, which was then sealed with a bung.
- Tube A was placed 10 cm away from a lamp.
- Tube B was placed 5 cm away from a lamp.
- Tube C was placed in a dark room.
- An oxygen sensor was used to measure the percentage of oxygen in the solutions at the start of the experiment and again at 5,10 and 20 minutes.
The results are shown in Fig. 4.2.
Fig. 4.2
[ 2 ]
Question (i)
(i)
State why sodium hydrogencarbonate solution was used.
[ 1 ]
Question (ii)
(ii)
Suggest what factor, which may have an effect on the rate of photosynthesis, was not taken into account in this experiment.
[ 1 ]
All question bank results loaded