During exercise a patient's heart rate is 120 beats/min and each side pumps 110 cm³ per beat. Cardiac output is the volume pumped by one side per minute.
.1
Calculate cardiac output in dm³/min.
[2 marks]
.2
Explain how increased cardiac output supports exercise.
[3 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A respirometer shows a germinating seed sample uses 2.4 cm³ oxygen in 8 minutes. Its mass is 3.0 g. An equal-mass boiled sample uses no measurable oxygen.
.1
Calculate oxygen uptake rate per gram in cm³ per minute per gram.
[2 marks]
.2
Explain the difference between the seed samples.
[2 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Root cells absorb nitrate from a solution with a lower nitrate concentration than the cells. A poison stops respiration without damaging the cell membrane.
.1
Explain why nitrate uptake decreases.
[3 marks]
.2
Explain why water can still cross the membrane.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Rose leaves develop black spots and fall early. A grower collects fallen leaves, then sprays a fungicide. A neighbour claims that antibiotics would always be a better treatment.
.1
Explain why early leaf loss reduces plant growth.
[2 marks]
.2
Evaluate the treatments described.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Oxygen volumes collected from pondweed in three 5-minute repeats are 4.5, 5.0 and 5.5 cm³. A second student counts bubbles instead of collecting gas.
.1
Calculate the mean oxygen production rate.
[2 marks]
.2
Evaluate counting bubbles compared with collecting gas volume.
