BIOLOGY 2E Chapter 1 THE STUDY OF LIFE

Fundamental vocabulary and concepts from Chapter 1 regarding the study of life, scientific methods, levels of biological organization, and taxonomy.

Biology

The study of living organisms and their interactions with one another and their environments.

Science

Knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method.

Scientific method

A method of research with defined steps that include experiments and careful observation.

Cyanobacteria

Formerly called blue-green algae, these are some of Earth’s oldest life forms and were shown at $300\times$ magnification under a light microscope.

Stromatolites

Ancient structures formed by the layering of cyanobacteria in shallow waters, such as those found along the shores of Lake Thetis in Western Australia.

Escherichia coli (E. coli)

Bacteria that are normal residents of our digestive tracts aiding in the absorption of vitamin K and other nutrients, though virulent strains can cause disease.

Inductive reasoning

A form of logical thinking that uses related observation to arrive at a general conclusion.

Deductive reasoning

A form of logical thinking that uses a general principle or law to forecast specific results.

Hypothesis

A suggested explanation for an event, which can be tested and must be falsifiable.

Scientific theory

A generally accepted, thoroughly tested, and confirmed explanation for a set of observation or phenomena.

Scientific laws

Descriptions of how elements of nature will behave under certain specific conditions, often expressed in mathematical formula.

Control

The component in an experiment that is not affected by changes occurring from the independent variable and is used for comparisons.

Independent Variable

The component in an experiment that varies or is manipulated by the researcher.

Dependent Variable

The response or results that is measured in an experiment.

Peer review

A blind process whereby scientists submit details of their experiments, results, and interpretations, and reviewers determine the veracity and merit for publication.

Basic science

Also known as “pure” science, it seeks to expand knowledge regardless of the short-term application of that knowledge.

Applied science

Science that aims to use scientific knowledge to solve immediate problems defined by the researcher.

Homeostasis

The property of life where an organism maintains internal balance, such as a polar bear maintaining body temperature.

Atom

The smallest and most fundamental unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons.

Molecule

Two or more atoms held together by a chemical bond.

Macromolecules

Large molecules formed by combining smaller units called monomers.

Organelles

Small structures that exist within cells and perform specialized functions, such as the Golgi apparatus and nucleus.

Cell

The smallest fundamental unit of a living organism; all living things are made up of these.

Tissues

Groups of similar cells that come together to carry out the same function.

Organs

Collections of tissues grouped together based on a common function.

Organ System

A level of organization that consists of functionally related organs.

Population

All the individuals of a species living within a specific area.

Community

The set of populations inhabiting a particular area.

Ecosystem

Consists of all the living things and abiotic (non-living) things in a particular area.

Biosphere

The collection of all ecosystems representing the zones of life on Earth, including land, water, and portions of the atmosphere.

Evolution

The process of gradual change during which new species arise from older species.

Hierarchical taxonomy

An organizational system proposed by Carl Linnaeus in the $18^{th}$ century that groups organisms by their similarities into increasingly specific categories.

Binomial naming system

A naming system where organisms are given two unique names: the capitalized genus and the lower-case species, both set in italics.

Prokaryotes

Single-celled organisms that do not have a membrane-bound nucleus nor organelles surrounded by a membrane, including those in domains Bacteria and Archaea.

Eukaryotes

Organisms with cells that possess a membrane-bound nucleus and other membrane-bound organelles.

Autotrophs

Also known as producers, these are photosynthesizing organisms that produce their own food for energy.

Heterotrophs

Also known as consumers, these organisms consume other organisms to obtain their energy.

Decomposers

Organisms such as fungi and bacteria that obtain energy by consuming and breaking down dead organisms.

Phylogenetic tree

A diagram showing evolutionary relationships among biological species based on similarities and differences in genetic or physical traits.

DNA

A complex molecule composed of atoms that controls cell activity by coding for the creation of proteins.