A level Exchange of substances, Energy transfers, Responses of organisms 2021

A 2g sample of biomass was fully combusted in a calorimeter. The volume of water was 100cm3. The increase in temperature recorded was 15.7C. 4.18 J of energy are needed to increase the temperature of 1c,3 of water by 1C. Use this information to calculate the heat energy released in kJ per g of biomass. (2) - 3.3kJg-1 A student correctly plotted the right ventricle on the same grid as the left ventricle in Figure 3. Describe one way the student's curve would be similar and one way it would be different from the curve shown in figure 3 (2) - 1. Contractions are at the same time 2. overall pressure is lower in the RV At P on Figure 3, the pressure in the L ventricle is increasing. At this time, the rate of blood flow has not yet increased in the aorta. Use evidence from figure 3 to explain why. (2) - 1. SL valves closed 2. because pressure is higher in aorta than in LV At Q on Figure 3 there is a small increase in pressure and the rate of blood flow in the aorta. Explain how this happens and why it is important. (2) - 1. elastic recoil of aorta tissue 2. which maint. blood flow Caclulate how many times greater the mean growth rate per day was using 37.5g potassium nitrate than using 37.5g ammonium sulfate. Assume the mean biomass of the spinach plants at the start of the investigation was 0.5g per pot. (1) - 4.9-0.5 = 4.4 3.7-0.5 = 3.2 4.4/3.2 = 1.4375