A student estimated the number of daisies in a field 50 m long and 40 m wide. She placed a 0.25 m² quadrat at five random positions and counted the daisies in each.
Daisies in five quadrats: 4, 7, 0, 5, 9.
Quadrat
1
2
3
4
5
Number of daisies
4
7
0
5
9
.1
Calculate the mean number of daisies per quadrat.
[2 marks]
.2
Estimate the number of daisies in the whole field.
[3 marks]
8 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student models a small organism as a cube with sides 3 cm long.
.1
Calculate the total surface area of the cube.
[2 marks]
.2
Calculate the volume of the cube.
[1 mark]
.3
Calculate the surface area to volume ratio of the cube.
[1 mark]
.4
A larger organism has a smaller surface area to volume ratio.
Explain why a large multicellular organism needs exchange surfaces and a transport system.
[2 marks]
.5
Explain why root hair cells need energy to take in mineral ions from the soil.
[2 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student used a potometer to measure the rate of water uptake by a leafy shoot. An air bubble moved along a scale as the shoot took up water.
In still air the bubble moved 45 mm in 5 minutes. With a fan blowing on the shoot, the bubble moved 72 mm in 5 minutes.
.1
Calculate the rate of water uptake in still air, in mm per minute.
[1 mark]
.2
Calculate the percentage increase in the rate when the fan was on.
[2 marks]
.3
Explain why the rate of water uptake increased when the fan was on.
[2 marks]
.4
Give one variable the student should keep the same when comparing still air with moving air.
[1 mark]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
The body keeps its temperature close to 37 °C.
.1
Explain why it is important to keep body temperature close to 37 °C.
[2 marks]
.2
Which of these is an effector?
[1 mark]
.3
Name the coordination centre that receives information from temperature receptors.
[1 mark]
3 marksFoundation
Spec and skills
Original practice question
Answer and supported method checks
A student put some pondweed in a beaker of water under a lamp. She collected the oxygen given off in an upturned 25 cm³ measuring cylinder that was full of water at the start.
The measuring cylinder's scale starts at 0 cm³ at its closed end, which is now at the top. As oxygen collects at the top, it pushes the water down.
After 10 minutes, the boundary between the oxygen and the water was at the 4.0 cm³ mark.
.1
What volume of oxygen did the student collect?
[1 mark]
.2
Calculate the rate of oxygen production in cm³ per minute.
[1 mark]
.3
Another student counted the bubbles of oxygen instead.
Suggest why measuring the volume of gas gives more accurate results than counting bubbles.
