TAXONOMY [CSEC BIOLOGY]

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SYLLABUS REFERENCE

  • [A1.1] group living organisms found in a named habitat based on observed similarities and differences; 
  • [A1.2] classify organisms into taxonomic groups based on physical similarities; 

Why is Classification so Important to Biology? 

Biology is a science.
Science is systematic knowledge of the physical or material world, gained through observation and experimentation. 

Systematic: done or acting according to a fixed plan or system; methodical. 

Biology is the scientific study of the living world, which can seem chaotic. Classification is a first step towards creating a framework and order within which the chaotic living world can be studied. 

One of the first steps of Biology is setting up a system to determine whether something is alive or not. Once something shows ALL the following characteristics, it is considered a living organism. That, and being made up or one or more cells. 


Millions of organisms exist, in a multitude of forms. 
A system is needed to make it easier to study them. One that places organisms into groups, based on shared features. Such a system also enables scientists to discover - as well as predict - relationships between organisms, according to their features. 

TAXONOMY is the science of developing such systems. 

Taxonomy: The science of producing a formal system for naming & classifying species. 

THERE ARE TWO TYPES OF CLASSIFICATION IN BIOLOGY 


THE BINOMIAL SYSTEM IS THE BASIS OF MOST CLASSIFICATION SYSTEMS 



The following are the mandatory categories in which organisms are placed, with two examples. Each group is called a TAXON. (Taxa, plural). 


HELPFUL MNEMONICS 


THE 5-KINGDOM SYSTEM 

Also known as the Whittaker system, having been proposed by RH Whittaker in 1969. 
It divides organisms first along the prokaryote - eukaryote line. 


Other Levels of Note... 

Blue - Phyla (Phylum, singular) 
Green - Classes (Class, singular) 

Note that all the Animal Phyla are invertebrates EXCEPT Chordata.

Here is a description of some of these groups... 

SPECIES - THE UNIT OF CLASSIFICATION 

Species: A group of organisms that can interbreed and produce fertile offspring. 

Each species has a scientific name with two parts (binomial): the Genus and species name. 

Example: the dog - Canis lupus; Human beings - Homo sapiens. 

PRACTICE QUESTIONS & ANSWER SCHEMES 











 

 

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