Cambridge A Level Biology A2 Effects of Limiting Factors Questions

[Maximum number: 6]

(a)

A student investigated the effect of temperature on the rate of photosynthesis at two different light intensities. The rate of photosynthesis was determined by measuring the rate of oxygen production of the plant.

Fig. 7.1 shows the result of the investigation.
rate of oxygen production $/ \mathrm{mm}^{3} \mathrm{~h}^{-1}$

Fig. 7.1

[ 6 ]

(i)

With reference to Fig. 7.1, describe and explain the results of the investigation for the plant in low light intensity.

Figure for Question (i) — CAIE A-Level Biology A2

[ 3 ]

(ii)

With reference to Fig. 7.1, describe and explain the results of the investigation for the plant in high light intensity above $30^{\circ} \mathrm{C}$ .

[ 3 ]

Any three from:
1. rate of oxygen produced / rate of photosynthesis decreased ;
2. two paired data quotes with units:

temperature / $^{\circ}\mathrm{C}$	rate of oxygen production / $\mathrm{mm}^3\,\mathrm{h}^{-1}$
30	4 / 4.00
40	2.55
50	0.65

Accept 0.62-0.65 for the 50 $^{\circ}\mathrm{C}$ value.

3. because enzyme / ATP synthase / NADP reductase / oxygen evolving complex denatured ;
Accept rubisco.
4. change in active site / fewer enzyme-substrate complexes ;

CAIE A-Level Biology A2 13.2.2 Effects of Limiting Factors Questions

Exam points

CAIE A-Level Biology A2 13.2.2 Effects of Limiting Factors Questions question 1

Question (a)

Question (i)

Question (ii)