Biodiversity
Middle School
Definition
The variety of living things in an area, including the range of different species, the genetic differences within them, and the variety of ecosystems. High biodiversity makes ecosystems more stable and resilient.
Worked examples
A rainforest contains thousands of tree species, millions of insect species, and countless microorganisms in its soil—far more than a wheat field.
High species variety and ecosystem complexity demonstrate high biodiversity.
Two coral reefs may both have clownfish, but genetic differences in disease resistance between populations add to biodiversity.
Biodiversity includes genetic variation within a single species, not just the number of species.
Common mistakes
- More animals in an area always means higher biodiversity → Higher biodiversity means more different species, not just more individuals A million identical wheat plants have lower biodiversity than a forest with fewer but varied species.
- Biodiversity only counts animal and plant species → Biodiversity includes all living things: bacteria, fungi, protists, plus genetic and ecosystem variety Microorganisms and the variety of habitats are essential parts of biodiversity.
Where you'll use it next
You'll apply biodiversity when studying ecosystem stability, conservation biology, human impacts on habitats, extinction and endangered species, and climate change effects in later biology and environmental science courses.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026