5.3: Classification of biodiversity
Teaching time: 4 hours Practical time: 0 hours
NB - some of the applications and understanding of this topic we cover in the DP Biology introduction
U3: Taxonomists classify species using a hierarchy of taxa.
U4: All organisms are classified into three domains.
U5: The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species.
A1: Classification of one plant and one animal species from domain to species level.
Key Vocabulary
Essential idea: Species are named and classified using an internationally agreed system.
Exercise 1: Explain the features of the binomial system
Retrieval practice and prior learning
Review topic 1.1 introduction to cells
Review topic 1.1 life in a paramecium
The Binomial System of Nomeclature
U2: When species are discovered they are given scientific names using the binomial system.
NoS: Cooperation and collaboration between groups of scientists—scientists use the binomial system to identify a species rather than the many different local names. (4.3)
Exercise 1: Copy this table into your google doc and complete it with the name, in the languages indicated, of the organisms A-E included below. Look at the table before you start because some of the names are given already and will help you make a start.
A
B
C
D
E
U8: Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.
Exercise 3: Discuss the following questions
Why do you think it is useful for scientists to adopt a scientific name?
What do you notice about the scientific name?
What is the name given to the system of naming organisms scientifically?
What are the key features of this system?
Exercise 4: Create a presentation on each of the following groups - one slide per taxon! (include the animal and plant phyla and the classes of the phylum chordata)
Animal phyla
A3: Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata.
Phylum Chordata: Classes
A4: Recognition of features of birds, mammals, amphibians, reptiles and fish.
Plant Phyla
A2: Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta.
Uses of classification
U6: In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species.
U7: Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species.
Dichotomous Keys
S1: Construction of dichotomous keys for use in identifying specimens.
Exercise 5: Construct a key (following the example) using organisms from one of the groups (A or B) given.
Example of a dichotomus key
Group A
Group B
