Two body-temperature sensors record one person during a warm afternoon. Sensor A reads 36.9, 37.0 and 37.1 °C. Sensor B always reads exactly 37.0 °C. Both are displayed to one decimal place.
.1
Explain why sensor A can be consistent with homeostasis.
[2 marks]
.2
Suggest why sensor B does not, by itself, prove better control.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A transect runs from a shaded wall into a lawn. Mean plant counts per quadrat at 0, 2, 4, 6 and 8 m are 1, 3, 6, 6 and 5 respectively.
.1
Describe the pattern in the data without claiming a cause.
[2 marks]
.2
Explain how to investigate whether light accounts for the pattern.
[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.
[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 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
After ovulation, progesterone rises. Later in a cycle with no pregnancy, progesterone falls.
.1
Explain the effect of progesterone while its concentration is high.
