OCR GCSE Biology A B6.1 Monitoring and Maintaining the Environment Exam Questions

About OCR GCSE Biology A B6.1 Monitoring and Maintaining the Environment

B6.1 opens Topic B6 Global challenges on the OCR Gateway Biology A course, assessed in Paper 2 (Foundation) or Paper 4 (Higher). It covers how scientists measure the distribution and abundance of organisms, and how human activities affect biodiversity, both negatively and positively. It builds on the ecosystem ideas in B4.1 and links to food production in B6.2. Examiners commonly test sampling methods and their calculations, evaluation of fieldwork, the effects of deforestation, pollution and climate change, and the benefits and difficulties of conservation, often in data-based questions.

What you need to know

• Quadrats Quadrats are placed at random coordinates to estimate the abundance of plants or slow-moving animals. Estimated population = mean number per quadrat / area of one quadrat x total area.
• Transects A line transect with quadrats placed at regular intervals shows how distribution changes across a habitat, for example from a hedge into a field. Abiotic factors such as light intensity can be measured at each point.
• Capture-recapture Animals are caught, marked harmlessly and released, then a second sample is caught later. Population = number in first sample x number in second sample / number marked in second sample.
• Biodiversity Biodiversity is the variety of species in an ecosystem or on Earth. High biodiversity makes ecosystems more stable and provides food, medicines and materials.
• Human impacts Deforestation, land use for farming and building, pollution of air, water and land, and climate change reduce biodiversity. Indicator species, such as lichens for air quality, can be used to monitor pollution.
• Maintaining biodiversity Strategies include breeding programmes, protecting habitats, reforestation, field margins and hedgerows, and reducing waste and carbon dioxide emissions. Conservation can conflict with economic needs such as farming and development.

Common mistakes in B6.1 Monitoring and Maintaining the Environment

• Placing quadrats where organisms look common. Quadrats must be placed randomly, for example using random number coordinates, to avoid bias.
• Using a transect to estimate total population. Transects show changes in distribution; random quadrats estimate abundance.
• Rearranging the capture-recapture equation incorrectly. Multiply the two sample sizes, then divide by the number of marked individuals recaptured.
• Saying biodiversity is the number of individuals. Biodiversity refers to the variety of species, not the number of organisms.
• Giving vague answers such as 'pollution kills animals'. Name the pollutant and explain its effect, for example fertiliser run-off causing eutrophication.

Try three B6.1 Monitoring and Maintaining the Environment exam-style questions