Pearson Edexcel · GCSE · Biology
Course version: 1BI0 · Version from Sept 2016
5.11B Describe different ways plant diseases can be detected and…
Full specification wording
Topic 5 – Health, disease and the development of medicines: 5.11B Describe different ways plant diseases can be detected and identified, in the lab and in the field including the elimination of possible environmental causes, distribution analysis of affected plants, observation of visible symptoms and diagnostic testing to identify pathogens
Detecting a plant disease means deciding that a plant is unhealthy; identifying it means working out the cause.
Checked against the Pearson Edexcel 1BI0 specification (opens in a new tab) on .
- Point 11 of 21
Study notes
From the checked teaching notes for this specification point.
The idea
Detecting a plant disease means deciding that a plant is unhealthy; identifying it means working out the cause. In the field, a grower first rules out environmental causes such as drought, waterlogging, nutrient deficiency or frost, because these can mimic disease symptoms. Next, the pattern of affected plants is analysed: a patchy, spreading distribution suggests an infectious pathogen, whereas a uniform pattern across a whole area may point to an environmental factor. Visible symptoms such as discoloured leaves, wilting, spots or stunted growth are observed and recorded. In the lab, diagnostic testing is used to identify the pathogen itself, for example by examining tissue under a microscope or using a specific test for a particular microorganism.
What earns the marks
- Eliminating possible environmental causes such as drought, poor nutrients or frost before concluding a plant is diseased.
- Analysing the distribution of affected plants to judge whether the pattern suggests an infectious pathogen or an environmental factor.
- Observing and recording visible symptoms such as discoloured or wilting leaves, spots or stunted growth.
- Carrying out diagnostic testing in the lab to identify the pathogen responsible.
- Recognising that field methods detect and narrow down causes, while lab testing identifies the specific pathogen.
Common mistakes and how to put them right
Assuming any unhealthy plant has a disease.
Put it right: Environmental causes must first be eliminated.
Thinking distribution analysis identifies the exact pathogen.
Put it right: It suggests whether the cause is infectious or environmental, and lab testing identifies the pathogen.
Believing visible symptoms alone confirm which pathogen is present.
Put it right: Diagnostic testing is needed to identify the pathogen.
Exam tips
- Match each option to the stage it belongs to: eliminating environmental causes, distribution analysis, symptom observation or diagnostic testing.
- Reject options that claim a field observation alone identifies the exact pathogen.
- Look for the word 'environmental' when a question asks what must be ruled out before diagnosing disease.
Try the lesson
The start of the Topic 5 – Health, disease and the development of medicines: 5.11B Describe different ways plant diseases can be detected and identified, in the lab and in the field including the elimination of possible environmental causes, distribution analysis of affected plants, observation of visible symptoms and diagnostic testing to identify pathogens lesson, made from checked teaching notes for this specification point.
Have a go first
A gardener notices that several tomato plants in one corner of a greenhouse have yellow, wilting leaves. Before assuming a pathogen is responsible, which action would best help eliminate a possible environmental cause?
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Topic 5 – Health, disease and the development of medicines: 5.11B Describe different ways plant diseases can be detected and identified, in the lab and in the field including the elimination of possible environmental causes, distribution analysis of affected plants, observation of visible symptoms and diagnostic testing to identify pathogens
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge