Introduction to Biology: Phylogenetic Trees, Domains, and the Scientific Method

Vocabulary flashcards covering phylogenetic trees, domain levels, distinctions between prokaryotes and eukaryotes, characteristics of viral vs. bacterial organisms, biological kingdoms, and core concepts of the scientific method.

Phylogenetic tree

A diagram used by scientists and researchers to understand the origin, evolution, and common ancestors of life.

Taxonomy hierarchy

An eight-level system used by scientists to name and organize organisms, ranging from the most inclusive level (domain) to the least inclusive level (species).

Domain Eukarya

The domain of eukaryotic organisms whose cells contain a true nucleus housing DNA; it includes animals, plants, protists, and fungi.

Prokaryotic organisms

Unicellular organisms belonging to the domains Bacteria and Archaea that do not have a nucleus and possess exposed DNA.

Viruses

Non-living particles that cannot survive independently and must infect a host cell to utilize its organelles and ribosomes to produce viral proteins.

Antibiotics

Medications used to treat bacterial infections, which cannot be used to treat viral infections.

Kingdom Protista

The most diverse group of eukaryotic organisms within the domain Eukarya, which can be unicellular or multicellular, and autotrophs or heterotrophs.

Autotrophs

Producers that utilize energy from their own production, such as plants capturing light energy from the sun.

Heterotrophs

Consumers and decomposers that obtain their energy from external sources.

Kingdom Animalia

A kingdom in the domain Eukarya consisting of multicellular heterotrophic organisms such as fish, frogs, and humans.

Kingdom Fungi

A kingdom in the domain Eukarya composed of multicellular heterotrophic organisms that act as decomposers.

Kingdom Plantae

A kingdom in the domain Eukarya consisting of multicellular autotrophs that capture light energy from the sun to act as producers.

Science

An approach to understanding the natural world through systematic observation and experimentation.

Scientific method

A step-by-step procedure utilized by scientists to conduct research, beginning with observation and hypothesis formation.

Observation

The initial step of the scientific method that involves observing the natural world and gaining knowledge before an experiment begins.

Hypothesis

A potential, testable explanation for an observation that can be supported or falsified by data, but can never be proven true.

Quantifiable data

Objective data collected during an experiment that can be measured and expressed using numerical values.

Sample size

The total number of subjects or individuals included in a treatment group or control group within an experiment.

Independent variable

The variable in an experiment that is directly manipulated by the investigator to determine its influence on the dependent variable.

Dependent variable

The factor measured in an experiment to evaluate the outcome, which changes depending on the manipulation of the independent variable.

Control group

The group in an experiment that does not receive the active treatment or variable being tested, serving as a comparator.

Experimental group

The group of subjects in an experiment that receives the specific treatment, vaccine, or therapy being tested.

Placebo

An inactive substance, such as sugar water, administered to a control group in place of an active medication or vaccine.