GRE Subject Test: Biology

This subject covers the key concepts and topics tested in the GRE Subject Test for Biology, including cellular biology, genetics, and ecology.

Basic Concepts

Principles of Ecology

The Study of Interactions

Ecology explores how living things interact with each other and their environments, from tiny bacteria to giant whales!

Levels of Organization

  • Individuals: Single organisms
  • Populations: Groups of the same species
  • Communities: Different species living together
  • Ecosystems: Communities plus their physical environment

Energy Flow & Food Webs

Sunlight powers life! Plants capture solar energy, animals eat plants, and so on. This energy transfer forms food chains and complex food webs.

Real-World Importance

Ecological knowledge helps us conserve species, manage resources, and tackle climate change.

Fun Facts

  • A keystone species can shape entire ecosystems!
  • Biodiversity boosts ecosystem resilience.

Examples

  • Removing wolves from Yellowstone affected the entire ecosystem, reshaping rivers and forests.

  • Coral bleaching impacts whole marine communities.

In a Nutshell

Ecology studies how organisms interact with each other and the environment at different scales.