4 marksFoundation and Higher
After rainfall, water enters soil and is taken up by trees. On a sunny day the air above the woodland contains more water vapour.
.1Explain how water moves from the soil to the atmosphere through the trees.
[2 marks] .2Describe two later processes that return this water to land as part of the cycle.
[2 marks] 4 marksHigher
A disease-resistance allele R is dominant. Plant A is RR and plant B is rr. Their offspring are then crossed with each other.
.1Construct the first cross and explain the genotype of its offspring.
[2 marks] .2Explain the predicted outcomes when two first-generation plants are crossed.
[2 marks] 4 marksFoundation and Higher
In a trial of a new cream, 84 of 140 treated patients improve. In an identical placebo group, 56 of 140 improve.
.1Calculate the difference in improvement rates in percentage points.
[2 marks] .2Evaluate the conclusion that the cream cures every user.
[2 marks] 4 marksFoundation and Higher
A chart shows an XX egg-producing parent and an XY sperm-producing parent. A student says that the egg determines whether the child is XX or XY.
.1Explain why the student’s statement does not follow the chromosome model.
[2 marks] .2Explain why an earlier XY child does not make an XX child more likely next time.
[2 marks] 4 marksHigher
A clinic diagnoses gonorrhoea in a patient with pain on urination. An initial antibiotic fails; tests identify a resistant bacterial strain.
.1Explain why an antibiotic can be appropriate for gonorrhoea but this antibiotic failed.
[2 marks] .2Explain how a barrier method reduces transmission and why pain relief alone does not prevent spread.
[2 marks] 