SSS1 Biology Classification of Living Things - Taxonomy

BEHAVIOURAL OBJECTIVES:

By the end of the lesson, students should be able to:

i. Briefly discuss the history of classification.
ii. Define classification of taxonomy.
iii. Define Binomial nomenclature.
iv. State three(3) features of the Kingdom Monera.
v. State three(3) features of the Kingdom Protista.
vi. State three(3) features of the Kingdom Fungi.

INTRODUCTION: There are over 2,000,000 known different organisms in the world today and probably over 1,000,000 are left to be discovered. All these living things have different characteristics such as shapes, size, colour, height. It will therefore be extremely difficult to study these millions of living things without first classifying them. Therefore, classification helps to give a universal scientific name to every species so that students of different languages will be able to know the scientific names of species.

History of classification

The system of classification of living things used today is based on that introduced by a Swiss scientist called Carl Von Linne(1707-1778). His name was latinized to Carolus Linnaeus. He published the classification of plants in 1753 and that of animals in 1758.

According to Carolus Linnaeus, living things are first split into kingdoms such as plants and animal kingdom. Kingdoms are further split into phyla in animals and divisions in plants. Each phyla or division is further broken down into classes. Each class is further broken down into classes. Each class is further broken down into families. Families to genera, genera are further broken down into species.

There are seven major groups used in classifying living things. They are:

N.B. Species is a population that can interbreed within themselves to produce fertile offspring. The basic unit of classification of living things is the Species.

Definition of Classification/Taxonomy

Classification or Taxonomy is defined as the grouping of living things into their kinds. The father of taxonomy is known as Carolus Linnaeus.

Three examples of classification are shown in the table below;

S/N	Classification	Man	Gorilla	Housefly
1.	Kingdom	Animalia	Animalia	Animalia
2.	Phylum	Chordata	Chordata	Arthropoda
3.	Class	Mammalia	Mammalia	Insecta
4.	Order	Primate	Primate	Diptera
5.	Family	Hominidae	Pongidae	Muscidae
6.	Genus	Homo	Gorilla	Musca
7.	Species	sapiens	gorilla	domestica

Definition of Binomial nomenclature

Binomial nomenclature is the system of giving two names to an organization. This system was developed by a Swedish botanist, Carolus Linnaeus in the 18th century. Scientifically, every living thing has two(2) names. The first name is the genus and must start with capital letter, the second name is the species and must start with a small letter, e.g. Homo sapiens(the scientific name for man).

Features of Kingdom Monera

i. Single celled.
ii. Motile or non-motile organisms.
iii. They are microscopic.
iv. Cell structure is simple.
v. No definite nucleus.
vi. Bacteria and blue green algae are members of Kingdom Monera.

Features of Kingdom Protista

i. Single celled.
ii. Motile or non-motile organisms.
iii. Cell structure is complex.
iv. Definite nucleus present.
v. Members include; Chlamydomonas and Amoeba.

Features of Kingdom Fungi

i. Members are non-motile.
ii. Consist of thread-like structures known as hyphae.
iii. Contains many nuclei.
iv. Members lack chlorophyll.
v. Members are saprophytic in nature.
vi. Members include; Mushroom, Toadstools, Breadmould, Slime mould, Rhizopus