2.1 Life As We Name It
1. Identify differences among domains and kingdoms.
Readings: 2: 46-47, 12: 2. Name common species using scientific nomenclature.
Reading Quiz Due before class on Wednesday Sept 16th
Assignment Reminder: Welcome Survey on Vista due Wed. Sept. 23rd
New Assignment: Student Attitudes about Biology, complete by Monday Sept. 21st
- a way of classifying and naming all living things
- based on similarities between organisms
Classifying living organisms has been of importance to biologists for hundreds of years.
Originally characteristics used were structural or morphological (how an organism looked). Organisms can also
be classified based on organisms’ ecological roles, their chemical characteristics and now a lot of importance is
place on how genetically similar organisms are (DNA comparisons).
Categorize the items below.
Come up with a scheme for grouping items according to their similarity. For example one characteristic they
all share is that they are worn on feet. Try to come up with a scheme to subdivide the shoes into different
categories. Within each category you should be able to continue to create smaller and smaller groups until you
have differentiated between each different shoe. For example you could first divide the shoes into two groups
such as those made from natural materials vs. those made from synthetics. Then within each of these two
groups you could continue to subdivide the shoes into smaller and smaller categories. Create your own
a) b) c) d) e) f)
QUESTION: What did you do first to create your scheme?
The Latin Binomial
Carolus Linnaeus (Carl von Linné) lived
from 1707 –1778 in Sweden. In 1758 he
published a book called ‘Systema Naturae’
(System of Nature) in which he presented his idea of
naming living organisms according to a Latin binomial, or
two-part Latin name
Example: Helianthus annuus, the sunflower (Latin taken originally from Greek
helios = sun and anthos = flower and from Latin annuus = annual)
Rules for the Latin Binomial:
1. underline or italicize, each part of the scientific name separately
2. capitalize genus, The genus (first part of the name) is always capitalized, the
specific epithet (second part of the name) is always written in small letters
If the genus is known, but the species is not, then the abbreviation sp. is used e.g.
What does this have to do with classification?
The Latin binomial created a universal name (so scientists could all be sure they were talking about the same
Linneaus also created a hierarchical filing system (grouping species into a hierarchy of successively more
general categories) which helped in understanding how organisms are related
Eg.: Domain Eukarya
Subclass Asteridae OR
Species Helianthus annuus
The most general or inclusive group is the domain (which groups least similar organisms together)
Classification schemes have changed over time
The earliest groupings just differentiated between Animals and Plants. Whittaker (1969) devised the 5
kingdom system, shown below. The Kingdom Monera composed the bacteria and the Kingdom Protista was a
grab bag of mostly single-celled organisms with nuclei.
Kingdoms vs. Domains
Carl Woese (1980s) created domains to
indicate how very different Archaebacteria
(ancient bacteria) are from eubacteria (true
bacteria) and Eukarya.
Today the protists, eubacteria and archaea
have been divided into a number of
kingdoms to better reflect shared ancestry
Within each domain there are a number of kingdoms. Within Domain Eukarya there are 4 major groups.
Refer to Table 12.2 on Page 317
Domain Kingdom Characterisitics Example
Euryarchaeota, microscopic single cells, sperically, cylindrical, spiral or cube
Korarchaeota and They are generally found in very harsh extreme environments
Nanoarchaeota) eg extreme hot conditions such as hot sulfur pits, very saline,
very cold, acidic or alkaline conditions. Kingdom Euryarchaeota
They differ from Bacteria in the composition of their cell walls Methanothermus fervidus
and membranes as well as the machinery by which they lives in hot ponds’ producing
synthesize DNA and proteins methane, cannot tolerate
Bacteria numerous groups microscopic single cells found in most environments on earth
within the domain. except a few of the most extreme. They lack a nucleus and
Some call them arrange their genetic material in a single circular chromosome
kingdoms, some call ( as do the Archaea). Cells are spherical, cylindrical or spiral
them phyla. The in shape.
number of groups at
this classification level Domain Bacteria. spirochaete
varies Borrelia burgdorferi
(FY =lyme disease)
Eukarya Plantae -obtain energy from the sun through photosynthesis. Their
cells contain organelles called chloroplasts which are the sites
-multicellular and contain some type of pigments to absorb
light and perform photosynthesis
-cell walls contain cellulose
Eukarya Fungi -obtain energy from dead organic matter by secreting
enzymes outside their cells to break down complex molecules
and then absorb the simple molecules into their cells
-produce spores to reproduce, multicellular, composed of thin
filaments called hyphae, cell walls contain chitin
Eukarya Animalia - ingest their food and breakdown the complex molecules
inside their bodies
-multicellular, motile for part or all of life cycle
-do not have cell walls, only cell membranes
Eukarya Protists -organisms are generally unicellular (although there are
There are numerous exceptions in the algae) and obtain their food by one or more
groups and how of the mechanisms of the other Eukarya kingdoms.
many should be -due to their diversity they have been divided into a number
called kingdoms vs. of different kingdoms
phyla is under
You will be shown a number of pictures of organisms in class. Identify which group you think each of these
organisms belongs to and why you think so.
Questions to consider:
1. Members of the Kingdom Plantae have rigid cell walls made out of cellulose and some other tough polymers
which support the plants and allow them to grow to some height. Members of Kingdom Animalia lack cell walls,
so what do they use as a means of support to allow them obtain some height?
2. What some scientific advances or techniques which have likely caused scientists to change old classification
schemes into 3 domains and numerous kingdoms within those domains?
3. Besides the Fungi which group or groups do you suspect that contain organisms which obtain energy from
decaying organic matter?
4. What is a shared feature between all members of the Domain Eukarya?
5. If plants and many fungi are not motile during some phase of their life cycle, how do they distribute
themselves into new areas to obtain necessary resources?
6. You go butterfly watching with a friend and using a field guide identify two species Polygonia progne and
Polygonia satyrus. How do you know that they are in the same class order and family within the Biological
7. There are only several basic cell shapes for Archaea and Bacteria. What are other characteristics within
these domains that would allow for more detailed classification into smaller subdivisions of organisms?
8. How would you determine which group this green organism belongs to? Even if you intuitively think you
know which group it belongs to…how would you know for sure?