Classification of Life Flashcards

Classification and Taxonomy

• Classification refers to grouping organisms based on shared characteristics.
• Taxonomy is the scientific study focused on classifying organisms through structural traits and genetic data.

Naming Organisms

• Binomial nomenclature is a two-word naming system for organisms, combining genus and species names.
• Scientific names are typically derived from Latin.

Taxonomic Hierarchy

• Organisms are categorized in a hierarchical system: domain > kingdom > phylum > class > order > family > genus > species.
• The smallest taxonomic unit is species, defined by organisms' ability to reproduce and create fertile offspring.

Cellular Structure

• Prokaryotic cells lack a nucleus and membrane-bound organelles, exemplified by bacteria.
• Eukaryotic cells contain a nucleus and organelles, represented by plants and animals.

Nutrition Types

• Heterotrophs obtain food by consuming other organisms, known as consumers.
• Autotrophs produce their own energy through processes like photosynthesis, recognized as producers.

Organism Types

• Unicellular organisms consist of a single cell, while multicellular organisms are composed of multiple cells.

Domains of Life

• Archaea is a domain that encompasses the kingdom Archaebacteria, consisting of unicellular organisms without a nucleus.
• Bacteria includes the kingdom Eubacteria, representing common unicellular bacteria.
• Eukarya includes all eukaryotic organisms, subdivided into kingdoms: Protista, Fungi, Plantae, and Animalia.

Kingdom Characteristics

• Archaebacteria: unicellular, no nucleus, resembles early Earth life forms.
• Eubacteria: unicellular, no nucleus, includes common modern bacteria.
• Protista: eukaryotic and mostly unicellular organisms.
• Fungi: eukaryotic, heterotrophic, largely multicellular, with cell walls made of chitin.
• Plantae: eukaryotic, autotrophic, multicellular, with cell walls made of cellulose; includes mosses and flowering plants.
• Animalia: eukaryotic, multicellular, heterotrophic, no cell walls; includes diverse life forms from sponges to mammals.

Evolutionary Relationships

• Cladograms visually represent evolutionary relationships among organisms, showing common ancestors.

Scientific Progress

• Approximately 2 million species recognized; the discovery of new organisms is an ongoing process.
• DNA and protein comparisons provide deeper insights into the relationships between organisms.

Language and Classification

• Latin is the standardized language for formatting scientific names.
• Domains represent the broadest category in current classification systems, including prokaryotes (no nucleus) and eukaryotes (with nucleus).

Taxonomic Confusion

• Phylum includes more organisms than the order, as it is a broader category within the classification hierarchy.

Flashcards covering key terms in classification of life, including taxonomy, binominal nomenclature, and taxa.