Chapter 1: An Introduction to the Study of Life

Vocabulary flashcards covering the key terms, levels of organization, evolutionary concepts, and scientific methods introduced in Chapter 1.

Biology

The scientific study of life.

Unicellular

Describing living organisms that consist of just one single cell.

Multicellular

Describing living organisms that consist of many, sometimes trillions of cells.

Cell

The fundamental unit of life.

Biosphere

The global ecological system consisting of all life on Earth.

Ecosystem

A system consisting of all the living and non-living components in a given area.

Community

An ecological level consisting of all the interacting populations in an ecosystem.

Population

A group of interacting individuals belonging to one species.

Organism

An individual living being.

Organ system

A group of organs that work together to perform body functions.

Organ

A structure consisting of multiple tissues that cooperate to perform a specific task.

Tissue

An integrated group of similar cells that work together.

Organelle

A specialized component of a cell that performs a specific function.

Molecule

A group of atoms bonded together.

Atom

The fundamental unit of matter.

Natural selection

The nonrandom unequal reproductive success among individuals, favoring traits that increase survival and reproduction.

Artificial selection

The selective breeding of organisms by humans over millennia to promote desirable traits.

Canis lupus

The scientific name for the gray wolf, which is the ancestor to all modern dogs.

Emergent properties

Novel properties that emerge at each new level of biological organization due to the interaction of parts in an increasingly complex system.

Kingdom Plantae

A kingdom in domain Eukarya containing multicellular organisms that use sunlight to produce sugars via photosynthesis.

Kingdom Fungi

A kingdom in domain Eukarya containing single-celled or multicellular organisms that decompose and digest dead organisms.

Kingdom Animalia

A kingdom in domain Eukarya containing multicellular organisms that eat and digest other organisms.

Protists

A catch-all category for all remaining eukaryotic organisms that are single-celled or multicellular and do not fit into Plantae, Fungi, or Animalia.

Discovery science

Scientific inquiry that relies on measurements and data collection to describe the natural world without being hypothesis-driven.

Hypothesis

A proposed explanation for an observation that is testable, narrow in scope, and subject to immediate testing.

Theory

A broad explanation supported by a large and growing body of evidence that explains a great many observations.

Controlled experiment

An experiment that investigates a hypothesis by changing only one variable at a time while holding all other variables constant.

Independent variable

The factor being manipulated by the researcher in an experiment, plotted on the X-axis of a graph.

Dependent variable

The response being measured in an experiment, plotted on the Y-axis of a graph.

Negative control

A control group in an experiment in which no change is expected to occur.

Positive control

A control group in an experiment in which a specific change is expected to occur.

Blind experiment

An experimental setup in which specific information is withheld from participants to reduce bias.

Placebo

A medically ineffective control treatment used in experimental medical studies.

Placebo effect

A phenomenon in which test subjects experience measurable improvements despite receiving an ineffective treatment because they believe they are receiving medicine.

Pseudoscience

Any field or set of claims falsely presented as having a scientific basis, characterized by unprovable claims, reliance on anecdotal evidence, and specific agendas.

Peer review

The evaluation of scientific work by impartial, qualified, anonymous experts before publication.

Primary source

Original scientific material presented directly by the experimenter, such as peer-reviewed journals, technical reports, and dissertations.

Secondary source

A description, review, or commentary based on primary source material, such as newspaper articles, Wikipedia, magazine articles, and books.

Confidence interval

A graphical element displaying the area of $95\%$ confidence for the true value of a dataset.