Grade 9 Science Unit 2: Ecosystems

Comprehensive vocabulary flashcards covering ecological principles, energy dynamics, biochemical cycles, and human environmental impacts from Grade 9 Science Unit 2 study sheets.

Ecology

The study of how organisms interact with each other and their environment.

Organism

One individual living thing, such as one rabbit.

Population

Members of the same species living in one area.

Community

All the different populations living in one area.

Ecosystem

Living and non-living things interacting in an environment.

Biotic factors

Living or once-living parts of an ecosystem.

Abiotic factors

Non-living parts of an ecosystem, such as water, sunlight, air and rocks.

Earth's four spheres

Atmosphere (air), hydrosphere (water), lithosphere (land and rocks), and biosphere (living things).

Producer

An organism that makes its own food, usually using sunlight.

Consumer

An organism that gets energy by eating other organisms.

Herbivore

A consumer that eats plants.

Carnivore

A consumer that eats animals.

Scavenger

An organism that eats dead animals.

Predator

An organism that hunts and eats another organism.

Prey

An organism that is hunted and eaten by a predator.

Competition

When organisms need the same limited resource, such as food, water, space or shelter.

Food chain

A diagram that shows one single pathway of energy.

Food web

A diagram that shows many connected food chains.

Food chain arrows

Arrows that point in the direction energy moves: from the organism being eaten to the organism that eats it.

Trophic levels

The feeding levels in a food chain: producer, primary consumer, secondary consumer, and so on.

10% rule

The ecological principle that about $10\%$ of energy at one trophic level transfers to the next level.

Energy transfer inefficiency

The loss of energy between levels because organisms use energy for life processes and movement, and much is released as heat or leaves as waste.

10% rule energy calculation

If grass has $10{,}000\,\text{J}$, sheep receive $1{,}000\,\text{J}$ and wolves receive $100\,\text{J}$, transferring only about $10\%$ at each step.

Photosynthesis

The process by which plants use light energy, carbon dioxide and water to make glucose and oxygen.

Word equation for photosynthesis

$$\text{Water} + \text{light energy} \rightarrow \text{glucose} + \text{oxygen}$$

Word equation for cellular respiration

$$\text{Glucose} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water} + \text{energy}$$

Balanced chemical equation for cellular respiration

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy}$$

Relationship between photosynthesis and cellular respiration

Their reactants and products are opposites: photosynthesis stores energy in glucose, while cellular respiration releases energy from glucose.

Water cycle processes

The four main processes of the water cycle: evaporation, condensation, precipitation and collection.

Evaporation

The process where liquid water changes into water vapour and enters the atmosphere.

Condensation

The process where water vapour cools and changes into tiny liquid droplets, forming clouds.

Precipitation

Water that falls from clouds as rain, snow, sleet or hail.

Transpiration

The process where plants release water vapour from their leaves into the atmosphere.

Carbon uptake in plants

The entry of carbon into plants when they take in carbon dioxide from the air during photosynthesis.

Processes releasing carbon dioxide

Cellular respiration and combustion (burning fuels or wood), along with decomposition returning carbon to the environment.

Nitrogen fixation

The process in which certain bacteria change nitrogen gas from the atmosphere into ammonia or other forms plants can use.

Biodiversity

The variety of living organisms in an area or ecosystem.

CHIPPO

An acronym standing for Climate change, Habitat loss, Invasive species, Pollution, Population growth and Overexploitation.

Invasive species

A species introduced to an area where it is not native that can spread and cause harm to the ecosystem.

Invasive species in Ontario

Examples of non-native harmful species including zebra mussels, emerald ash borers and garlic mustard.

Easter Island human impact

An example of human impact where heavy use of resources and deforestation damaged the environment, contributing to habitat loss, soil erosion and resource shortages.

Human dependence on ecosystems

The reliance of humans on ecosystems to provide food, clean water, oxygen, medicine, materials and other resources.

Environmental stewardship

Taking responsibility for protecting and caring for the environment.

Bioaccumulation

The buildup of a harmful substance inside one organism over time.

Biomagnification

The process whereby the concentration of a harmful substance becomes greater at higher levels of a food chain.

Community environmental actions

Actions a community can take to help protect the environment, such as reducing waste, planting native species, joining cleanups, raising awareness and contacting government representatives.

Sustainability

Using resources in a way that meets people's needs now without preventing future generations from meeting needs.