Lesson 8 and 9- Classification and Cladistics

Lesson Objectives

Content Objective: Classification is the process of putting organisms into grouping based on their similarities to each other

Language Objective: Describe the major phyla of organisms and to create dichotomous keys.

Science of Classification

The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses
When species are discovered they are given scientific names using the binomial system
Taxonomists classify species using a hierarchy of taxa
The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family and genus and species
In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species
Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.

Classification of Organisms

All organisms are classified into three domains
Classification of one plant and one animal species from domain to species level
Recognition features of bryophyte, filicinophyta, coniferophyta, and angiospermophyta
Recognition features of porifera, cnidarian pletyhelmintha, annelida, Mollusca, arthropda and chordata
Recognition of features of birds, mammals, amphibians, reptiles and fish
Construction of dichotomous keys for use in identifying specimens
Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species.