Equal masses of fat are mixed with equal lipase concentrations at 37 °C. A has large droplets at pH 3; B has large droplets at pH 8; C has small droplets at pH 8. This lipase works best near pH 8.
.1
Explain why B should digest fat faster than A.
[2 marks]
.2
Explain why C should be faster than B and relate this to bile.
[2 marks]
6 marksHigher4.1.1.5 Microscopy
AQA Trilogy 8464
Spec and skills
Paper scope: B1
Spec 4.1.1.5
Original practice question
Answer and supported method checks
A researcher needs to observe chloroplast movement in living cells and examine internal membranes below the resolution limit of a light microscope.
Evaluate light and electron microscopy for these tasks.
[6 marks]
6 marksHigher4.3.1.7 Vaccination
AQA Trilogy 8464
Spec and skills
Paper scope: B1
Spec 4.3.1.7
Original practice question
Answer and supported method checks
A town offers a vaccine against a serious droplet-spread disease. Some residents cannot receive it for medical reasons. A group argues that vaccination is purely an individual choice with no effect on other people.
Evaluate the group's claim using vaccination and transmission.
[6 marks]
6 marksFoundation and Higher4.2.3.2 Plant organ system4.2.3.1 Plant tissues
AQA Trilogy 8464
Spec and skills
Paper scope: B1
Spec 4.2.3.2
Spec 4.2.3.1
Original practice question
Answer and supported method checks
Two plants grow under the same bright, warm conditions. One has plentiful water; the other has dry soil and closes many stomata.
Explain how closing stomata helps the dry-soil plant but can limit its growth.
[6 marks]
4 marksFoundation and HigherRequired practical 024.1.3.2 Osmosis
AQA Trilogy 8464
Spec and skills
Paper scope: B1
Spec 4.1.3.2
Original practice question
Answer and supported method checks
Plant tissue gains 4% mass at 0.20 mol/dm³ sugar and loses 4% at 0.40 mol/dm³. Assume a linear relationship between these points.
.1
Estimate the concentration giving zero net mass change.
[2 marks]
.2
Explain what zero net change means and how to improve the estimate.
