Build the mathematical and data-presentation skills required by the syllabus, using current question evidence to practise percentage increase, rounding and rate calculations.
State how the student would calculate the rates of photosynthesis from the results in Table 6.1.
Scientists measured the rate of photosynthesis in the leaves of a sunflower plant, Helianthus annuus.
The scientists used the apparatus shown in Fig. 3.1 to measure the rate of photosynthesis.
Fig. 3.1
The scientists carried out another investigation using the same apparatus at different temperatures.
They measured the rate of uptake of carbon dioxide in the light and then they measured the rate of release of carbon dioxide in the dark.
The results are shown in Fig. 3.2.
rate of carbon dioxide uptake and release per hour per of leaf
Fig. 3.2
Explain why the results in Table 3.1 are expressed as 'per of leaf' rather than 'per leaf'.
Fig. 4.1 is a diagram of a virus.
Fig. 4.1
The human immunodeficiency virus (HIV) infects and destroys lymphocytes.
The number of lymphocytes in the blood of a person infected with HIV was measured over a period of 84 months.
The results are shown in Fig. 4.2.
number of lymphocytes per of blood
Fig. 4.2
Describe the changes in the number of lymphocytes, over the 84 months following infection with HIV, shown in Fig. 4.2.