GCSE Edexcel Higher Biology · Topic 9 of 9
Choose a subtopic. Communities, ecosystems, biodiversity, trophic levels and material cycles. 41 lessons in 6 subtopics.
Revise Topic 9: Ecosystems and material cycles for GCSE Edexcel Higher Biology, including Adaptations, interdependence and competition.
41
Lessons
6
Subtopics
Topic 9: Ecosystems and material cycles has 6 subtopics:
41 lessons, grouped by subtopic.
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Communities, ecosystems, biodiversity, trophic levels and material cycles. 41 lessons in 6 subtopics.
To find the median, arrange all values in ascending order, then take the middle value. The Working with ecological data notes cover this in full.
The mode is the value that appears most frequently in a data set; a data set can have no mode, one mode or multiple modes. The Working with ecological data notes cover this in full.
Biodiversity is the variety of all the different species of organisms on Earth, or within an ecosystem, including plants, animals, fungi, bacteria and all other living things. The What is Biodiversity and Why Does it Matter? notes cover this in full.
Precipitation is water falling from clouds as rain, snow, sleet or hail. The The carbon and water cycles notes cover this in full.
Biomass is the total mass of living organisms in a given area or volume, measured in grams per square metre (g/m²) or kilograms per hectare (kg/ha). The Understanding Pyramids of Biomass notes cover this in full.
A producer is an organism that synthesises molecules using energy from the environment, usually through photosynthesis, converting light energy into chemical energy stored in glucose. The Producers and feeding relationships notes cover this in full.
Eutrophication is the process where excess nutrients in water cause algae blooms, leading to oxygen depletion and ecosystem damage, resulting in fish kills and loss of biodiversity. The Types and Sources of Pollution notes cover this in full.
An apex predator is a predator at the top of its food chain with no natural predators when fully grown, often a tertiary consumer. The Understanding Trophic Levels in Ecosystems notes cover this in full.