BIOLOGY 20: Diversity & Evolution - Classifying Organisms

Flashcards covering the 5 kingdoms of life, 3 domains of life, hierarchical classification, Linnean binomial nomenclature, and dichotomous keys based on lecture notes for BIOLOGY 20: Diversity & Evolution.

What was the first classification system developed by naturalists?

The Scala Natura, a ladder-like system ranging from rocks to God.

Who developed a more scientific 5-kingdom classification system in the 1950s?

Robert Whittaker

What were the 5 kingdoms in Whittaker's system?

Monera, Protista, Fungi, Plantae, Animalia

What was the primary characteristic of the Monera kingdom?

No nucleus, cell walls, included all bacteria.

What characterized the Protista kingdom?

Unicellular organisms with a nucleus, including autotrophs and heterotrophs.

What characterizes organisms in the Fungi kingdom?

Mostly decomposers (heterotrophs), have nuclei and cell walls.

What are the key features of the Plantae kingdom?

Multicellular and photosynthetic, cells have nuclei and cell walls.

What defines the Animalia kingdom?

Multicellular heterotrophs, cells have nuclei but no cell walls.

What discovery led to comparisons and changes in the classification of groups like Monera and Protista?

The discovery of DNA allowed comparisons of nucleic acid sequences.

Who proposed the 3 Domain Model of classification?

Carl Woese

What are the three domains in the 3 Domain Model?

Eubacteria, Archae, Eukaryota

What distinguishes Eubacteria?

True bacteria, no nuclei, cell walls, includes typical bacteria like salmonella and e-coli.

What are Archae?

Extremophile bacteria that live in harsh environments.

What is the defining feature of Eukaryota?

All organisms that organize their DNA into a nucleus.

In a hierarchical classification system, which level is the broadest and which is the most exclusive?

Domains/kingdoms are the broadest, species is the most exclusive.

What is the Biological Species Concept?

Species can interbreed to form viable and fertile offspring.

Who developed a two-part naming system for organisms called binomial nomenclature?

Carl Linnaeus

What two parts make up an organism's name in binomial nomenclature?

Genus and species.

What is a tautonym?

When a genus and species name are the same (e.g., Gorilla gorilla).

What is a dichotomous key used for?

To classify or identify organisms based on their visible characteristics.