Ecology and Human Impacts on the Biosphere – Vocabulary Review

30 vocabulary flashcards covering core concepts from the Unit I Ecology and Human Impacts lecture notes.

Scientific Method

A process of scientific thinking that involves making observations, proposing a hypothesis, designing and performing experiments, and drawing conclusions.

Observation

The first step in science; noticing patterns or cause-and-effect relationships in the natural world.

Hypothesis

A tentative, testable explanation for an observed phenomenon that generates predictions.

Experiment (Experimental Design)

A carefully structured test of a hypothesis in which variables are controlled to reveal cause-and-effect relationships and produce reproducible results.

Experimental Group

The set of subjects in an experiment that receives the independent variable or treatment being tested.

Control Group

The group in an experiment that does not receive the independent variable, providing a baseline for comparison.

Independent Variable

The factor intentionally manipulated by the experimenter to determine its effect.

Dependent Variable

The measured outcome that responds to changes in the independent variable.

Biology

The science that defines life and studies living organisms and their processes.

Ecology

The branch of biology that studies how organisms interact with each other and with their environment.

Biosphere

The global sum of all ecosystems; all regions of Earth inhabited by living organisms.

Biotic Components

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

Abiotic Components

The nonliving physical and chemical factors of an ecosystem (e.g., sunlight, water, soil, temperature).

Trophic Level

A feeding position in a food chain or web through which energy and nutrients flow (producer, consumer, etc.).

Producer

An organism, typically photosynthetic, that converts solar energy into chemical energy (e.g., plants, algae).

Primary Consumer (Herbivore)

An organism that eats producers for energy (e.g., rabbit, grasshopper).

Secondary Consumer (Carnivore)

An organism that eats primary consumers (e.g., frog, small bird).

Tertiary Consumer

A higher-level predator that feeds on secondary consumers in a food chain.

Omnivore

A consumer that eats both plant and animal matter (e.g., bears, humans).

Detritivore

An organism that feeds on dead organic matter, helping fragment it (e.g., earthworms, millipedes).

Decomposer

A microbe (bacteria, fungi) that chemically breaks down dead organisms and waste, recycling nutrients back to the ecosystem.

Energy Pyramid

A diagram that illustrates energy loss between trophic levels; roughly 10 % of energy is passed on, 90 % is lost as heat or waste.

Photosynthesis

The process in which light energy, water, and CO₂ are used by plants, algae, and some bacteria to produce sugars and O₂.

Chloroplast

The plant-cell organelle that contains chlorophyll and is the site of photosynthesis.

Chlorophyll

The green pigment in chloroplasts that captures sunlight energy for photosynthesis.

Cellular Respiration

A process, mainly in mitochondria, that converts glucose and O₂ into CO₂, water, and ATP to fuel cellular activities.

ATP (Adenosine Triphosphate)

The cell’s primary energy carrier; about 32 molecules are produced per glucose during cellular respiration.

Bioaccumulation

The gradual build-up of toxic substances in an organism’s tissues, leading to higher concentrations at higher trophic levels.

Carbon Cycle

The continuous movement of carbon through living organisms, the atmosphere, oceans, and geologic reservoirs via fast and slow pathways.

Greenhouse Effect

The trapping of heat in Earth’s atmosphere by greenhouse gases, resulting in global warming and driving climate change.