Science - 2018-19

LS.4 - Classification

The student will investigate and understand how organisms can be classified. Key concepts include

a) the distinguishing characteristics of domains of organisms;

b) the distinguishing characteristics of kingdoms of organisms;

c) the distinguishing characteristics of major animal phyla and plant divisions; and

d) the characteristics that define a species. 

Bloom's Levels:  Analyze; Understand

Adopted: 2010


  • Organisms are diverse, yet share similar characteristics.
  • Life can be organized into a functional and structural hierarchy.

  • I can identify how humans are similar to other organisms.
  • I can classify a newly discovered (or new to me) organism and relate it to other, similar organisms.


  • Information about physical features and activities is arranged in a hierarchy of increasing specificity. The levels in the accepted hierarchy include domain, kingdom, phylum, class, order, family, genus and species.
  • Current classification systems now generally recognize the categorization of organisms into three domains, Archaea, Bacteria and Eukarya.
  • As living things are constantly being investigated, new attributes (physical and chemical) are revealed that affect how organisms are placed in a standard classification system. This system is the basis for scientific binomial nomenclature.
  • Any grouping of organisms into domains or kingdoms is based on several factors, including the presence or absence of cellular structures, such as the nucleus, mitochondria, or a cell wall; whether the organisms exist as single cells or are multicellular; and how the organisms get their food. For example, simple, single-celled organisms that are able to survive in extreme environments are believed to be fundamentally different from other organisms and may be classified in their own domain (Archaea). Four different kingdoms of the Eukarya domain of organisms are generally recognized by scientists today (Protista, Fungi, Plants, and Animals).
  • Some important animal groups (phyla) are the cnidarians, mollusks, annelids, arthropods, echinoderms, and chordates.
  • Four important plant groups (divisions) are the mosses, ferns, conifers, and flowering plants.
  • A group of similar-looking organisms that can interbreed under natural conditions and produce offspring that are capable of reproduction defines a species.


In order to meet this standard, it is expected that students will

a)  categorize examples of organisms as representative of the three domains (Archaea, Bacteria and Eukarya) and recognize that the number of domains is subject to change as new data are collected.

b)  categorize examples of organisms as representative of the kingdoms and recognize that the number of kingdoms is subject to change as new data are collected.

c)  recognize examples of major animal phyla.

recognize examples of major plant divisions.

d)  classify organisms based on a comparison of key physical features and activities.

arrange organisms in a hierarchy according to similarities and differences in features.

a, b, c, d)  recognize scientific names as part of a binomial nomenclature.


classification groups/levels, mnemonic for classification levels, species, binomial nomenclature, six kingdoms of classification, animal phyla, important plant groups

Updated: Jun 29, 2018