Science MP QUIZ

Ecology

The study of the relationships between organisms and their environment

Habitat

The place where an organism lives including both biotic and abiotic factors

Niche

The role or job of an organism in its environment

Generalist

An organism that eats a wide variety of foods and can live in many environments

Specialist

An organism that has a limited diet and specific habitat needs

Atmosphere gases

Nitrogen (78%)

Purpose of atmosphere

Blocks UV rays

Earth's four spheres

Atmosphere

Gaia Hypothesis

The idea that Earth behaves like a living organism that self-regulates

Biotic factors

Living parts of an ecosystem (e.g.

Abiotic factors

Non-living parts of an ecosystem (e.g.

Organism

An individual living thing (e.g.

Population

A group of the same species living in an area

Community

All the populations of different species living and interacting in an area

Ecosystem

A community of organisms and their abiotic environment

Pond ecosystem biotic factors

Frogs

Pond ecosystem abiotic factors

Still water

Sustainable ecosystem

An ecosystem that can maintain balance and function over time

Features of sustainable ecosystems

Biodiversity

Photosynthesis

Process by which producers convert CO₂ and H₂O into sugar using sunlight

Photosynthesis word equation

Carbon dioxide + water → sugar + oxygen

Cellular respiration

Process by which organisms break down sugar to release energy

Cellular respiration word equation

Sugar + oxygen → carbon dioxide + water + energy

Producer

An organism that makes its own food via photosynthesis (e.g.

Consumer

An organism that eats other organisms for energy

Ecological niche

The role and interactions of a species in its environment

Herbivore

A consumer that only eats plants

Carnivore

A consumer that only eats other animals

Omnivore

A consumer that eats both plants and animals

Scavenger

A consumer that feeds on dead or decaying animals

Food chain

A sequence showing what eats what in an ecosystem

Food web

A network of interconnected food chains

Trophic level

A step in a food chain (e.g.

Effect of removing species

Prey may increase

Effect of adding new species

Can disrupt food webs or outcompete native species

Energy transfer between levels

Only about 10% of energy passes to the next level

Energy pyramid

Diagram showing energy loss through trophic levels

Number pyramid

Diagram showing the number of organisms at each trophic level

Biomass pyramid

Diagram showing the total mass of organisms at each level

Biogeochemical cycle

Natural cycles that move matter (e.g.

Water cycle steps

Evaporation

Human disruption of water cycle

Pollution

Carbon cycle main parts

Photosynthesis

Human impact on carbon cycle

Burning fossil fuels and deforestation add CO₂

Nitrogen importance

Needed for DNA and proteins

Nitrogen fixation

Bacteria convert nitrogen gas into usable forms for plants

How animals get nitrogen

By eating plants or other animals

Decomposers in nitrogen cycle

Break down matter and return nitrogen to the soil

Denitrification

Process by which bacteria return nitrogen to the atmosphere

Human impact on nitrogen cycle

Overuse of fertilizer causes runoff and algal blooms

Limiting factor

Any condition that restricts the size of a population

Biotic limiting factors

Predators

Abiotic limiting factors

Water

Tolerance range

The full range of conditions in which an organism can survive

Optimal range

Ideal conditions for growth and reproduction

Human impact on terrestrial ecosystems

Deforestation

Human impact on aquatic ecosystems

Thermal pollution

Species interaction types

Competition

Mutualism example

Nitrogen-fixing bacteria and plant roots

Parasitism example

Tapeworm in a dog

Commensalism example

Barnacles on a whale

Carrying capacity

Maximum population size that an ecosystem can support

What happens when population exceeds carrying capacity

Resource shortage

How humans affect carrying capacity

By increasing or decreasing resources like water or shelter

Abiotic Factor

The non-living physical and chemical elements in an ecosystem (e.g.

Biotic Factor

The living components of an ecosystem (e.g.

Photosynthesis

The process by which green plants use sunlight to convert carbon dioxide and water into glucose and oxygen.

Cellular Respiration

A process in which cells break down glucose and oxygen to release energy (ATP)

Producer

An organism that makes its own food using sunlight (photosynthesis) or chemicals (chemosynthesis); also called autotroph.

Consumer

An organism that obtains energy by feeding on other organisms; also called heterotroph.

Herbivore

A consumer that eats only plants (e.g.

Carnivore

A consumer that eats only other animals (e.g.

Omnivore

An organism that eats both plants and animals (e.g.

Decomposer

An organism that breaks down dead organisms and recycles nutrients into the ecosystem (e.g.

Food Chain

A linear sequence showing how energy and nutrients flow from one organism to another.

Food Web

A complex network of interconnected food chains in an ecosystem.

Trophic Level

The level or position an organism occupies in a food chain (e.g.

Primary Consumer

An organism that eats producers; usually a herbivore.

Secondary Consumer

An organism that eats primary consumers; usually a carnivore or omnivore.

Tertiary Consumer

A predator that eats secondary consumers; top of the food chain.

Energy Pyramid

A diagram showing how energy decreases at each trophic level; only ~10% of energy is transferred upward.

Biomass

The total mass of all living organisms at a given trophic level.

Limiting Factor

A condition that restricts the growth

Carrying Capacity

The maximum population size that an environment can sustain over time without degrading resources.

Ecological Niche

The specific role an organism plays in its environment

Competition

Occurs when organisms compete for the same resource (e.g.

Predation

Interaction where one organism (predator) hunts and eats another (prey).

Mutualism

A symbiotic relationship where both species benefit (e.g.

Parasitism

A symbiotic relationship where one organism benefits and the other is harmed (e.g.

Commensalism

A symbiotic relationship where one species benefits and the other is unaffected (e.g.

Biodiversity

The variety of life in an area; includes genetic

Ecological Succession

The natural process of change in ecosystems over time; species are replaced gradually.

Primary Succession

Succession that starts from bare rock or lava where no soil exists (e.g.

Secondary Succession

Succession that occurs after a disturbance in an area with existing soil (e.g.

Invasive Species

Non-native species that spread rapidly and disrupt ecosystems (e.g.

Native Species

A species that occurs naturally in a given area or ecosystem.

Sustainability

The ability of ecosystems to remain diverse and productive over time without human-caused degradation.

Bioaccumulation

The buildup of toxic substances (like mercury or pesticides) in an organism over time.

Biomagnification

The increasing concentration of toxic substances in organisms at higher trophic levels in a food chain.