science exam part 1 - ecology

Ecology

The study of relationships between living organisms and their physical environment. Example: studying energy movement through food webs.

Ecosystem

All living organisms and their physical and chemical environments. Example: aquatic ecosystem.

Population

A group of individuals of the same species living in the same area. Example: Toronto's human population.

Community

How populations interact with each other and their surroundings. Example: Toronto’s community.

Habitat

The natural environment of an organism. Example: forests.

Niche

The role or function a species serves in its ecosystem. Example: spider in the food chain.

Biome

An area classified by the species that live there. Example: rainforest.

Biosphere

Where life exists in the atmosphere, lithosphere, and hydrosphere. Example: Atlantic Ocean.

Sustainability

The ability to maintain ecological balance. Example: not cutting down trees.

Equilibrium

A balance of living and nonliving things in an ecosystem. Example: predator-prey balance.

Symbiotic relationship

Ongoing interaction between organisms of different species. Example: predation.

Predation

One individual feeds on another. Example: lynx preys on snowshoe hares.

Mutualism

Both individuals benefit. Example: nitrogen-fixing bacteria and plant roots.

Competition

Two individuals compete for the same resource. Example: humans and insects for crops.

Parasitism

One lives in or on a host and feeds on it. Example: tapeworms in cats and dogs.

Commensalism

One benefits, the other is unaffected. Example: Spanish moss on trees.

Biodiversity

The variety of all living things and their interactions.

Atmosphere

The layers of gases extending upward. Example: oxygen gas.

Hydrosphere

All Earth’s water in solid, liquid, or gas form. Example: icebergs.

Lithosphere

The rocky shell of Earth. Example: North America.

Biosphere (again)

Where life exists across Earth's systems. Example: Atlantic Ocean.

Most abundant gas on Earth

78% nitrogen gas and 21% oxygen gas.

Biotic factors

Living things in an ecosystem. Example: animals.

Abiotic factors

Non-living components of an ecosystem. Example: water.

Food chain

A sequence showing energy transfer from one organism to the next.

Food web

A diagram of feeding relationships within a community.

Producer

Organism that makes its own food using sunlight. Example: grass or algae.

Primary consumer

Eats producers. Example: rabbit or zooplankton.

Secondary consumer

Eats primary consumers. Example: snake or small fish.

Tertiary consumer

Eats secondary consumers. Example: hawk or killer whale.

Autotroph

Organism that makes its own food (producer). Example: trees or phytoplankton.

Heterotroph

Organism that relies on others for food (consumer). Example: humans or lions.

Decomposer

Breaks down dead organic matter. Example: fungi or bacteria.

Carnivore

Animal that eats other animals. Example: wolf or eagle.

Omnivore

Animal that eats both plants and animals. Example: bear or raccoon.

Herbivore

Animal that eats plants or producers. Example: cow or caterpillar.

Energy pyramid

Shows energy loss and transfer between trophic levels.

10% Rule

Only 10% of energy is passed to the next level; 90% is used for survival.

Photosynthesis (word)

Carbon dioxide + Water → Sugar + Oxygen.

Photosynthesis (chemical)

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.

Cellular respiration (word)

Sugar + Oxygen → Carbon dioxide + Water.

Cellular respiration (chemical)

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O.

Deforestation

The action of clearing a wide area of trees; disrupts water and nutrient cycles.

Fragmentation

Breaking up a region into smaller parts. Example: limits wildlife habitats.

Native species

A species naturally found in an area.

Non-native species

A species introduced to an area by humans.

Invasive species

A non-native species that harms the ecosystem.

Bioaccumulation

The gradual build-up of substances like pesticides in organisms.

Human threats to species

Activities that can lead to species becoming extinct or threatened: hunting, deforestation, fragmentation, and introducing invasive species to ecosystems.