Overview
This lecture explains the concepts of classification and taxonomy, detailing how living things are grouped and named in biology.
Classification in Biology
- Classification organizes organisms into categories based on shared characteristics.
- Categories range from broad to specific: domain, kingdom, phylum, class, order, family, genus, species.
- The domain is the broadest grouping; species is the most specific.
- Knowing the order of these categories in both directions is required for exams.
- Classification becomes more specific as you move down the hierarchy.
Taxonomy and Binomial Nomenclature
- Taxonomy is the science of naming and categorizing organisms.
- Binomial nomenclature assigns each organism two names: the genus and species.
- Genus is always capitalized and either italicized or underlined.
- Species is always lowercase and also italicized or underlined; never use bold.
- Examples include Homo sapiens (humans), Gorilla gorilla (gorilla), Streptococcus pneumoniae (bacterium), and Boa constrictor.
- Binomial names are universal to avoid confusion among scientists worldwide.
Key Terms & Definitions
- Classification — grouping organisms based on similarities.
- Taxonomy — science of naming and classifying organisms.
- Binomial Nomenclature — two-part scientific naming system (genus and species).
- Genus — the general group name for an organism; capitalized.
- Species — the specific name for an organism; lowercase.
Action Items / Next Steps
- Memorize the classification hierarchy: domain, kingdom, phylum, class, order, family, genus, species.
- Practice writing scientific names correctly (genus capitalized, species lowercase, both italicized or underlined).
- Review the scientific name for humans: Homo sapiens.