Structural adaptations (physical features):

  • Camouflage: animals like chameleons blend in with their environment so it is harder for predators to catch them

  • Fur: animals living in cold climates have thick fur coats to help them keep warm

Behavioral adaptations (activities):

  • Nocturnal animals: animals like mice only come out at night so that they can avoid predators that hunt during the day

  • Migration: animals make long seasonal trips to different regions, which can help them find more food, move to places with a better climate, or for other reasons

Populations, Communities, and Ecosystems

Population: all the organisms of the same species that live in the same place at the same time

  • A group of frogs living in a pond

Community: multiple populations that live in the same place at the same time

  • Groups of fish, frogs, ducks, and lily pads that live in that pond

Ecosystem: a community and the nonliving factors in its environment

  • All the organisms in the pond as well as non-living things such as water and rocks

Food Webs

A food web shows the connections between organisms in an ecosystem and shows what eats what.

Levels of a food web:

Producers: take in the sun’s energy and make their own food (examples: grass, trees, flowers, algae)


  • Primary consumers: herbivores that eat producers for energy (examples: rabbits, cows, deer)

  • Secondary consumers: carnivores that eat primary consumers (examples: lions, tigers)

  • Tertiary consumers eat secondary consumers and so on

  • Animals can belong to multiple levels of a food web: omnivores eat both producers (plants) and consumers (animals) (examples: foxes, bears)


  • An organism that breaks down dead bodies of organisms at every level (examples: mushrooms, bacteria)

Habitats and Niches

Habitat: place where an organism lives that provides food, water, shelter, and space to the organism

Niche: the function that an organism performs in the food web of that community, as well as everything the organism does and needs in its environment

  • No two types of organisms occupy exactly the same niche in a community.

During its life cycle, an organism’s role in the community (niche) may change.

  • Tadpoles and adult frogs have different interactions with their environment

Human Impacts

Humans can have major impacts on ecosystems, positive or negative.

Positive impacts:

  • Protecting endangered species: conserving species keeps ecosystems intact

  • Cleaning oceans and rivers: by doing this, we are providing a clean habitat for organisms

Negative impacts:

  • Deforestation: humans cut down trees, which disrupts ecosystems

  • Pollution: humans release chemicals into the air and water, which harms organisms

  • Global warming: the new hotter temperatures affect the balance of ecosystems


Sources Used and Helpful Links