Students want to test whether doing mental arithmetic changes ruler-drop reaction time. They will use a safe classroom investigation with volunteers. You may compare drop distances directly: longer distances indicate slower reactions.
Plan the investigation so that the results can support a valid comparison.
[6 marks]
4 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
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 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student writes: “Homeostasis stops all changes. Only the brain controls it. Muscles and glands detect every stimulus.”
Evaluate this description of homeostasis. Explain how automatic control systems actually work.
[6 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student says: "DNA is copied after mitosis because daughter cells only need half the genetic information at first."
.1
Explain why this account is incorrect.
[3 marks]
.2
Explain why mitosis is useful in healing a skin wound.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A contraceptive comparison gives typical-use pregnancies per 100 users in one year: method A, a daily hormonal pill, 8; method B, an implant, 1. Neither method protects against sexually transmitted infections.
.1
Calculate the difference in expected pregnancies between 500 users of A and 500 users of B for one year.
[2 marks]
.2
A person often forgets daily medication and also wants infection protection. Evaluate these methods for that person.
