The first affected plant in a crop is recorded near one corner of a field. Over the next three weeks, new affected plants appear progressively farther from this plant. Soil moisture and mineral supply are similar across the field.
Which conclusion is best supported?
the pattern identifies a particular pathogen, but does not show its distribution
the pattern establishes mineral deficiency, because neighbouring plants are affected
the pattern excludes infection, because environmental conditions are similar
the pattern is consistent with spread of a pathogen, but does not identify it
45 exam-style questions on Edexcel GCSE Biology 5.2 Plant and body defences, covering 5.2.1 Physical plant defences, 5.2.2 Chemical plant defences, 5.2.3 Detecting plant diseases, and 5.2.4 Human physical and chemical defences. Each one has a worked solution and a mark scheme showing where the marks go.