Summary
Biodiversity refers to the variety of life on Earth, encompassing diversity within species, between species, and of ecosystems. Extinction is a natural process where species die out, often accelerated by human activities.
- Extinction — the dying out of a species. Example: Dinosaurs went extinct due to a mass extinction event.
- Ecosystem — a community of organisms and their environment. Example: A forest with trees, animals, and microorganisms.
- Niche — the role of an organism in its ecosystem. Example: Bees pollinate flowers, helping plants reproduce.
- Species Diversity — the number of species and their relative abundance in an area. Example: A rainforest with many different tree species.
- Genetic Diversity — the variety of genes within a species. Example: Different dog breeds have genetic diversity.
- Heterozygosity Index — a measure of genetic diversity within a species. Example: High heterozygosity in a population indicates many individuals have different alleles.
- Sampling Methods — techniques to study species distribution. Example: Using quadrats to count plant species in a field.
- Index of Diversity (D) — a measure of biodiversity considering species richness and evenness. Example: A high D value indicates a diverse ecosystem.
Exam Tips
Key Definitions to Remember
- Extinction
- Ecosystem
- Niche
- Species Diversity
- Genetic Diversity
Common Confusions
- Confusing species richness with species diversity
- Misunderstanding the role of genetic diversity in adaptation
Typical Exam Questions
- What is biodiversity? Biodiversity is the variety of life on Earth, including diversity within species, between species, and of ecosystems.
- How does climate change affect extinction rates? Climate change alters habitats, making them unsuitable for some species, leading to extinction.
- What is the role of zoos in conservation? Zoos help conserve species through captive breeding and education.
What Examiners Usually Test
- Understanding of biodiversity levels
- Ability to explain causes of extinction
- Knowledge of conservation methods