Evolution, Themes of Biology, and Scientific Inquiry Vocabulary

Vocabulary terms and definitions from Chapter 1 on Evolution, Themes of Biology, and Scientific Inquiry.

Community

All the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for potential interaction.

Organ

A specialized center of body function composed of several different types of tissues.

Model Organism

A particular species chosen for research into broad biological principles because it is representative of a larger group and usually easy to grow in a lab.

Organism

An individual living thing, consisting of one or more cells.

Bacteria

One of two prokaryotic domains, the other being Archaea.

Deductive Reasoning

A type of logic in which specific results are predicted from a general premise.

Technology

The application of scientific knowledge for a specific purpose, often involving industry or commerce but also including uses in basic research.

Prokaryotic Cell

A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes.

Eukaryotic Cell

A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with eukaryotic cells (protists, plants, fungi, and animals) are called eukaryotes.

Independent Variable

A factor whose value is manipulated or changed during an experiment to reveal possible effects on another factor (the dependent variable).

Organelle

Any of several membrane-enclosed structures with specialized functions, suspended in the cytosol of eukaryotic cells.

Producer

An organism that produces organic compounds from $CO_2$ by harnessing light energy (in photosynthesis) or by oxidizing inorganic chemicals (in chemosynthetic reactions carried out by some prokaryotes).

Experiment

A scientific test, often carried out under controlled conditions that involve manipulating one factor in a system in order to see the effects of changing that factor.

Data

Recorded observations.

Evolution

Descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones; also defined more narrowly as the change in the genetic composition of a population from generation to generation.

Ecosystem

All the organisms in a given area as well as the abiotic factors with which they interact; one or more communities and the physical environment around them.

Deoxyribonucleic Acid

A nucleic acid molecule, usually a double-stranded helix, in which each polynucleotide strand consists of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T); capable of being replicated and determining the inherited structure of a cell's proteins.

Proteomics

The systematic study of sets of proteins and their properties, including their abundance, chemical modifications, and interactions.

Science

An approach to understanding the natural world.

Dependent Variable

A factor whose value is measured during an experiment or other test to see whether it is influenced by changes in another factor (the independent variable).

Experimental Group

A set of subjects that has (or receives) the specific factor being tested in a controlled experiment. Ideally, the experimental group should be identical to the control group for all other factors.

Inquiry

The search for information and explanation, often focusing on specific questions.

Systems Biology

An approach to studying biology that aims to model the dynamic behavior of whole biological systems based on a study of the interactions among the system's parts.

Population

A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.

Archaea

One of two prokaryotic domains, the other being Bacteria.

Biology

The scientific study of life.

Theory

An explanation that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence.

Inductive Reasoning

A type of logic in which generalizations are based on a large number of specific observations.

Climate Change

A directional change in temperature, precipitation, or other aspect of the global climate that lasts for three decades or more.

Eukarya

The domain that includes all eukaryotic organisms.

Genome

The genetic material of an organism or virus; the complete complement of an organism's or virus's genes along with its noncoding nucleic acid sequences.

Gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses).

Genomics

The systematic study of whole sets of genes (or other DNA) and their interactions within a species, as well as genome comparisons between species.

Hypothesis

A testable explanation for a set of observations based on the available data and guided by inductive reasoning. A hypothesis is narrower in scope than a theory.

Controlled Experiment

An experiment designed to compare an experimental group with a control group; ideally, the two groups differ only in the factor being tested.

Bioinformatics

The use of computers, software, and mathematical models to process and integrate biological information from large data sets.

Molecule

Two or more atoms held together by covalent bonds.

Emergent Properties

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases.

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Consumer

An organism that feeds on producers, other consumers, or nonliving organic material.

Gene Expression

The process by which information encoded in DNA directs the synthesis of proteins or, in some cases, RNAs that are not translated into proteins and instead function as RNAs.

Feedback Regulation

The regulation of a process by its output or end product.

Biosphere

The entire portion of Earth inhabited by life; the sum of all the planet's ecosystems.

Cell

Life's fundamental unit of structure and function; the smallest unit of organization that can perform all activities required for life.

Tissue

An integrated group of cells with a common structure, function, or both.

Variable

A factor that varies in an experiment.

Proteome

The entire set of proteins expressed by a given cell, tissue, or organism.

Null Hypothesis

A hypothesis that predicts no effect or no relationship between variables, which a researcher tries to disprove.

Alternative Hypothesis

A hypothesis that states the research prediction of an effect or relationship between variables, which a researcher tries to prove.

Placebo

A treatment that appears real but is designed to have no therapeutic benefit (e.g., a 'dummy' treatment or 'sugar pill').

Single-Blind Study

An experiment in which patients do not know which study group they are in (for example, whether they are taking an experimental drug or a placebo).

Double-Blind Study

An experiment in which neither the patients nor the researchers/doctors know which study group the patients are in.

Five Unifying Themes in Biology

Evolution, organization, information, energy and matter, and interactions.

Scientific Method Flowchart Diagram

A sequential diagram outlining steps in scientific inquiry: #1 Observation, #2 Question, #3 Hypothesis, #4 Prediction, #5 Experiment or Observation, #6 Conclusion.