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 person with Type 1 diabetes says that insulin lowers blood glucose because it destroys glucose molecules in the bloodstream.
.1
Explain why this explanation is incorrect.
[2 marks]
.2
Explain why a person with Type 1 diabetes may need insulin treatment even when they avoid sugary foods.
[2 marks]
4 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
Researchers record 48 freshwater invertebrate species at an unpolluted site and 18 at a site with low dissolved oxygen. The sites also differ in temperature and water flow.
.1
Calculate the percentage decrease in species count relative to the unpolluted site.
[2 marks]
.2
Evaluate the claim that low oxygen alone caused the decrease.
[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
A potometer reservoir initially contains 24.0 cm³ of water. After 90 minutes it contains 17.7 cm³. A sealed control loses no water. The student claims that all 6.3 cm³ must have evaporated from the leaves.
