Grade 9 Science Ecology

What is ecology?

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

What is an ecosystem?

A community of organisms interacting with each other and with the non-living parts of their environment.

What are biotic factors?

The living parts of an ecosystem, such as plants, animals, fungi, and bacteria.

What are abiotic factors?

The non-living parts of an ecosystem, such as sunlight, temperature, water, soil, air, and pH.

What is a producer?

An organism that makes its own food, usually through photosynthesis.

What is a consumer?

An organism that gets energy by eating other organisms.

What is a decomposer?

An organism such as fungi or bacteria that breaks down dead organisms and waste and returns nutrients to the environment.

What is a herbivore?

A consumer that eats plants or other producers.

What is a carnivore?

A consumer that eats other animals.

What is an omnivore?

A consumer that eats both plants and animals.

What does sustainability mean?

Using resources in a way that meets our needs today without preventing future generations from meeting their needs.

What is a predator?

An organism that hunts and eats another organism.

What is prey?

An organism that is hunted and eaten by a predator.

What is a predator-prey relationship?

A relationship where one organism hunts and eats another organism.

What is competition?

A relationship where organisms compete for limited resources such as food, water, space, territory, or mates.

What is mutualism?

A relationship where both organisms benefit.

What is commensalism?

A relationship where one organism benefits and the other is not significantly affected.

What is parasitism?

A relationship where one organism benefits while the other is harmed.

What is symbiosis?

A close, long-term relationship between two different species.

What happens to prey populations when predator populations increase?

Prey populations generally decrease because more prey are being eaten.

What can happen to predator populations when prey populations decrease?

Predator populations may decrease because there is less food available.

What is a food chain?

A model showing the transfer of energy from one organism to another through eating.

What is a food web?

A network of interconnected food chains showing multiple feeding relationships.

What does an arrow mean in a food chain?

It shows the direction that energy moves, from the organism being eaten to the organism eating it.

What is a trophic level?

A feeding position in a food chain or food web.

What is the first trophic level?

Producers.

What is the second trophic level?

Primary consumers.

What is the third trophic level?

Secondary consumers.

What is the fourth trophic level?

Tertiary consumers.

What is a primary consumer?

An organism that eats producers, usually a herbivore.

What is a secondary consumer?

An organism that eats primary consumers.

What is a tertiary consumer?

An organism that eats secondary consumers.

What is a top or apex predator?

A predator at or near the highest trophic level that generally has few or no natural predators.

What is a pyramid of energy?

A diagram showing the amount of energy available at each trophic level.

Why does energy decrease as you move up a food chain?

Organisms use much of the energy they obtain for life processes, and much of it is released as heat.

What is the 10% rule?

Approximately 10% of the energy at one trophic level is transferred to the next trophic level.

What is a pyramid of biomass?

A diagram showing the total mass of living organisms at each trophic level.

What is a pyramid of numbers?

A diagram showing the number of organisms at each trophic level.

Which trophic level usually has the most available energy?

Producers.

What is the carbon cycle?

The movement of carbon between the atmosphere, living organisms, soil, oceans, and Earth.

Why is carbon important?

Carbon is a major component of living organisms and is found in carbohydrates, proteins, fats, and DNA.

How does carbon enter plants?

Plants take in carbon dioxide from the atmosphere during photosynthesis.

What is photosynthesis?

The process plants use to convert light energy, carbon dioxide, and water into glucose and oxygen.

What is the word equation for photosynthesis?

Carbon dioxide + water + light energy → glucose + oxygen.

What is cellular respiration?

The process cells use to release usable energy from glucose.

What is the word equation for cellular respiration?

Glucose + oxygen → carbon dioxide + water + energy.

How are photosynthesis and cellular respiration connected?

The products of one process are the reactants of the other.

How does carbon return to the atmosphere?

Through cellular respiration, decomposition, combustion, and other processes.

How does burning fossil fuels affect the carbon cycle?

It releases large amounts of stored carbon as carbon dioxide into the atmosphere.

What are fossil fuels?

Coal, oil, and natural gas formed from ancient organisms over millions of years.

What is a toxin?

A poisonous substance that can harm an organism.

What is bioaccumulation?

The gradual buildup of a substance such as a toxin within an individual organism over time.

What is biomagnification?

The concentration of a toxin increases as it moves to higher trophic levels in a food chain.

What is the difference between bioaccumulation and biomagnification?

Bioaccumulation is the buildup of a toxin within one organism, while biomagnification is the increase in toxin concentration between trophic levels.

Why are top predators often most affected by biomagnification?

They eat many organisms from lower trophic levels, causing toxins to become concentrated in their bodies.

What types of substances are likely to biomagnify?

Persistent substances that break down slowly and are difficult for organisms to eliminate.

What is a native species?

A species that naturally occurs in a particular ecosystem or region.

What is a non-native species?

A species that occurs in an area where it does not naturally occur.

What is an invasive species?

A non-native species that spreads and causes ecological, economic, or social harm.

Are all non-native species invasive?

No. A species can be non-native without becoming invasive.

How can an invasive species affect an ecosystem?

It may compete with native species, eat native organisms, spread disease, alter habitats, or disrupt food webs.

Why can invasive species spread quickly?

They may have few natural predators or competitors in their new environment.

What is pollution?

The introduction of harmful substances or energy into the environment.

What is water pollution?

The contamination of water by harmful substances or waste.

How do humans contribute to water pollution?

Through sewage, industrial chemicals, fertilizers, pesticides, oil spills, plastic waste, and runoff.

What is air pollution?

Harmful substances released into the atmosphere.

What are some sources of air pollution?

Vehicles, factories, fossil-fuel power plants, fires, and industrial activities.

What is eutrophication?

The process where excess nutrients in water cause excessive plant or algae growth and can lead to low oxygen levels.

What is an algal bloom?

A rapid increase in algae, often caused by excess nutrients.

Why can algal blooms kill fish?

When algae die and decompose, decomposers use oxygen, which can cause low-oxygen conditions that kill aquatic organisms.

How can humans affect ecosystems overall?

Through pollution, habitat destruction, climate change, overharvesting, urbanization, agriculture, and introducing non-native species.

What is soil?

A mixture of mineral particles, organic matter, water, air, and living organisms.

What are the three main particle sizes in soil?

Sand, silt, and clay.

Which soil particle is largest?

Sand.

Which soil particle is smallest?

Clay.

Which soil particle is intermediate in size?

Silt.

What is sandy soil like?

It has large particles, drains quickly, and usually holds fewer nutrients.

What is clay soil like?

It has very small particles, holds lots of water, and drains slowly.

What is silt soil like?

It has medium-sized particles and generally holds more water and nutrients than sandy soil.

What is loam?

A soil mixture containing a relatively balanced combination of sand, silt, and clay.

Why is soil important to ecosystems?

It provides plants with water and nutrients, supports organisms, stores carbon, filters water, and provides habitat.

What is humus?

Decomposed organic matter in soil that contributes nutrients and improves soil structure.

How can you separate soil particles in a soil sample?

Mix soil with water and allow particles to settle into layers according to particle size and density.

What order do soil particles generally settle from bottom to top?

Sand → silt → clay → organic material.

How do you calculate the percentage of a soil type?

Percentage = (amount of that soil type ÷ total amount of soil) × 100.

What is pH?

A measure of how acidic or basic a substance is.

What is a pH of 7?

Neutral.

What is below pH 7?

Acidic.

What is above pH 7?

Basic or alkaline.

Why is soil pH important?

It affects nutrient availability and which plants and organisms can successfully live in the soil.

What is the water cycle?

The continuous movement of water through Earth's atmosphere, land, oceans, and living organisms.

What is evaporation?

The change of liquid water into water vapour because of heat energy.

What is condensation?

The process where water vapour cools and changes into liquid water droplets.

What is precipitation?

Water falling from the atmosphere as rain, snow, sleet, or hail.

What is runoff?

Water flowing over Earth's surface into streams, rivers, lakes, and oceans.

What is infiltration?

Water soaking into the ground.

What is transpiration?

Water vapour being released from plants.

What is a biological indicator?

A living organism or biological community whose presence, absence, or abundance gives information about environmental conditions.

What is a non-biological indicator?

A physical or chemical measurement used to assess environmental health.

What are examples of biological indicators?

Types and abundance of aquatic insects, fish, algae, and other organisms.