Taxonomy – Classification of Living Organisms
Taxonomy is the science of __________________ groups of organisms based on their
_________________________. Our taxonomic system was developed by Swedish botanist ________
__________________________ in the 1700’s. He grouped organisms by their _______________
characteristics. Now, we also use ______________________ and ______________________
information to classify organisms.
All organisms are slotted into eight nested levels of taxonomic categories known as ranks. The
ranks go from biggest to smallest. This is a hierarchical system.
Domain K____________ P___________ C_________ O________ F_________ G______ S_________
There are 8 different groups called ________ (singular - ______________)
that are used to classify organisms . _______________ is the largest and
most general taxon but is often skipped. Kingdom is the second largest
taxon. Species is the _______________ _ taxon as it includes only a single
type of organism. A species is defined as individuals that can _______
____________________________________
Three Types of Evidence Used
Organisms have ______________________________ in their environment.
Taxonomy helps us classify organisms to see how _________________
they are. The taxonomic relationship between two organisms is based on
three types of evidence:
1.
Anatomical evidence – do the ___________________ of the
organisms look the same?
2.
Physiological evidence – do the _________________________ in the
cells work the same?
3.
DNA evidence - how genetically closely related are the ___________
and the __________________ they make?
What is a Domain?
A domain is the highest level of taxonomic classification. The three domains are
____________________________________________. Bacteria and Archaea are also names of
_______________. The domain Eukarya contains the other 4 kingdoms of _______________________
_______________________________
The domains are based on two types of cells - ___________________ and ________________________.
Bacteria and Archaea are prokaryote cells ______________________ and ______________________
and are much ______________________. All the
organisms in the domain Eukarya have cells that
evolved a nuclear membrane to protect DNA and they
have organelles like Golgi apparatus and endoplasmic
reticulum.
Taxonomic classification often skips the domain and
starts with the kingdoms.
Bacteria - also called __________________
Archaea – _______________________ in the 1990’s
______________
______________
_______________
_______________
Characteristics of the Six Kingdoms
This chart describes the main characteristics that differentiate the organisms in the six kingdoms. As we
study each kingdom you should focus on the _______________________________________________
___________________________________________________________________________
Viruses – Living or Not?
Viruses do have ______________ but reproduce only inside a host organism; Do not have _______ ;
Cannot make _____________ themselves; Cannot use _______________________. So without a
host a virus is simply a group of chemicals. So _____________________________
____________________ and do not get a taxonomic classification.
Taxonomy – Classification of Living Organisms
What is taxonomy?
Taxonomy is the science of classifying groups of organisms based on their characteristics.
Our taxonomic system was developed by Swedish botanist Carolus Linneaus in the 1700’s.
He grouped organisms by their physical characteristics. Now, we also use genetic and biochemical
information to classify organisms.
All organisms are slotted into eight nested levels of taxonomic categories known as ranks. The ranks go
from biggest to smallest. This is a hierarchical system.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
There are 8 different groups called taxa (singular - taxon) that are used to
classify organisms .
Domain is the largest and most general taxon but is often skipped.
Kingdom is the second largest taxon. Species is the smallest taxon as it
includes only a single type of organism.
A species is defined as individuals that can interbreed and produce fertile
offspring.
Three Types of Evidence Used
Organisms have evolved to survive in their environment. Taxonomy helps
us classify organisms to see how closely related they are. The taxonomic
relationship between two organisms is based on three types of evidence:
Anatomical evidence – do the structures of the organisms look the same?
Physiological evidence – do the proteins and enzymes in the cells work the
same?
DNA evidence - how genetically closely related are the genes and the
proteins they make?
What is a Domain?
A domain is the highest level of taxonomic classification
The three domains are Bacteria, Archaea, and Eukarya
Bacteria and Archaea are also names of kingdoms
The domain Eukarya contains the other 4 kingdoms of Protista, Fungi, Plantae and Animalia

The domains are based on two types of cells - prokaryotes and eukaryotes.

Bacteria and Archaea prokaryote cells lack a nucleus and membrane bound organelles and are
much smaller.

All the organisms in the domain Eukarya have cells that evolved a nuclear membrane to protect
DNA and they have organelles like Golgi apparatus and endoplasmic reticulum.
Taxonomic classification often skips the domain and starts with the kingdoms shown below:

Bacteria - also called Monera or Eubacteria

Archaea – separated from bacteria in the 1990’s

Protista

Fungi

Plantae

Animalia
Characteristics of the Six Kingdoms
This chart describes the main characteristics that differentiate the organisms in the six kingdoms. As we
study each kingdom you should focus on the cell types, number of cells, the cell wall material, nutrition
and reproduction.
Viruses – Living or Not?

Viruses do have nucleic acids but reproduce only inside a host organism

Do not have cells

Cannot make proteins themselves

Cannot use energy
Without a host a virus is simply a group of chemicals.
So viruses are not considered living organisms and do not get a taxonomic classification.