Ecology Grade 9

Finals ecology key terms

Ecology

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

Abiotic

Non-living parts of the environment (like sunlight, water, and temperature).

Biotic

The living components of an ecosystem, including plants, animals, and microorganisms.

Species

A group of organisms that can interbreed and produce fertile offspring.

K. Archaebacteria

A domain of single-celled microorganisms that can thrive in extreme environments, often distinct from bacteria and eukaryotes.

Retrovirus

A type of virus that inserts its genetic material into the DNA of a host cell, often causing chronic infections.

Zoonotic Virus

A virus that can be transmitted from animals to humans, often causing disease.

Biodiversity

The variety of life in the world, including the variety of species, ecosystems, and genetic diversity within species.

Marine

biodiversity includes various marine species and ecosystems.

Estuary

A coastal area where freshwater from rivers meets and mixes with saltwater from the ocean, supporting diverse ecosystems.

Trophic Level

A step in the food chain that defines the position of organisms based on their feeding relationships, including primary producers, consumers, and decomposers.

Omnivore

An organism that eats both plants and animals.

Commensalism

A type of symbiotic relationship where one organism benefits while the other is neither helped nor harmed.

Limiting Factor

Any condition that restricts a population's growth, such as food availability or habitat space.

Sustainability

The ability to maintain ecological balance by using resources in a way that does not deplete them for future generations.

K. Eubacteria

A kingdom of single-celled organisms that are prokaryotic, lacking a nucleus. They play essential roles in various ecological processes.

K. Fungi

Kingdom of organisms like mushrooms and mold that break down dead things.

K. Plantae

Kingdom of plants; they make their own food through photosynthesis.

K. Protista

Kingdom of mostly single-celled organisms that don't fit into other groups (like algae).

K. Animalia

Kingdom of animals — multicellular, move, and eat other organisms.

Genetic Engineering

Changing the DNA of an organism for a specific purpose.

Unicellular

Made of only one cell (like bacteria).

Multicellular

Made of many cells (like humans, plants, animals).

Lytic Cycle

A viral cycle where the virus quickly copies itself and bursts the host cell.

Lysogenic Cycle

A viral cycle where the virus integrates its genetic material into the host cell's DNA and remains dormant until triggered to enter the lytic cycle.

Tropical Biomes

Biomes near the equator — hot and either very wet (rainforest) or very dry (desert).

Freshwater

Water without salt — like rivers, lakes, ponds.

Producer

An organism that makes its own food (like plants using photosynthesis).

10% Rule

Only 10% of energy moves from one trophic level to the next in a food chain.

Herbivore

An organism that only eats plants.

Lichen

A mix of fungi and algae that live together in a mutualistic relationship.

Cuticle

A waxy layer on plant leaves that helps prevent water loss.

Flower

The reproductive part of a plant where seeds are made.

Angiosperm

A flowering plant that produces seeds inside a fruit.

Invertebrate

An animal with no backbone (like insects, jellyfish, worms).

Population

All the members of one species in an area.

Community

All the different living things in an area.

Temperate Biomes

Biomes with changing seasons — not too hot or cold (like forests or grasslands).

Decomposer

Decomposer

Organisms that break down dead things and return nutrients to the soil (like fungi and bacteria).

Predator-Prey

A relationship where one organism hunts and eats another.

Carnivore

An organism that only eats other animals.

Parasitism

A relationship where one organism benefits and the other is harmed (like a tick on a dog).

Keystone Species

A species that has a big impact on its ecosystem (removing it would change everything).

Global Warming

The Earth's average temperature is increasing because of human activities.

Invasive Species

A non-native species that spreads and harms the environment, economy, or health.

Vertebrate

An animal with a backbone (like mammals, birds, reptiles).

Virus

A tiny non-living particle that infects cells and needs them to reproduce.

Capsid

The protein shell that surrounds a virus’s genetic material.

Biome

A large area with similar climate, plants, and animals (like desert, tundra, rainforest).

Ecosystem

All the living and nonliving things in an area and how they interact.

Permafrost

Frozen soil found in tundra biomes that stays frozen year-round.

Secondary Consumer

Eats primary consumers (like a snake eating a mouse).

Tertiary Consumer

Eats secondary consumers (like a hawk eating the snake).

Primary Consumer

Eats producers (like a rabbit eating grass).

Chemical Cycles

Cycles that move elements like carbon, nitrogen, and water through the Earth and living things.

Carrying Capacity

The maximum number of organisms an environment can support.

Niche

An organism’s role or job in its environment (what it eats, where it lives, etc.).

Greenhouse Effect

The trapping of heat in Earth’s atmosphere by greenhouse gases (like CO₂).

Mutualism

A relationship where both organisms benefit (like bees and flowers).

Finite

Limited — something that can run out (like oil or clean water).