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
A model of hormonal contraception keeps oestrogen and progesterone at concentrations that inhibit FSH and LH.
.1
Explain how this model reduces the chance of pregnancy.
[3 marks]
.2
Explain why this hormone model does not predict protection from sexually transmitted pathogens.
[1 mark]
6 marksFoundation and Higher
Spec and skills
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]
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 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
Four plants all have genotype RR at one tested gene, but their final heights are 14, 19, 24 and 27 cm. The plants grew with different supplies of water. A student claims that these results show height cannot be inherited.
.1
Explain why the student’s conclusion is not justified.
[3 marks]
.2
Suggest how to test the effect of water while reducing genetic differences between plants.
